Chapter 01 13e CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 1) Cell theory is one of the foundations of biology. What are the tenets of the cell theory? Check all that apply. A) All organisms aremade up of more than one cell. B) All cells have theability to move. C) Cells carry geneticmaterial passed to daughter cells during cellular division. D) Cells arise fromother cells through the process of cell division. E) Organisms are formed throughspontaneous generation F) All livingorganisms consist of cells
2) Darwin's theory of evolution is supported by many modern pieces of evidence. Check all that apply. A) New measurements ofthe age of the earth. B) Anunderstanding of the mechanism of heredity. C) Human populationgrowth. D) Comparativestudies of animal structures. E) Similaritiesin DNA of related species.
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 3) Science is subdivided into specific areas of study termed disciplines. These divisions are artificial but are helpful to narrow the massive scope of scientific knowledge to a manageable amount. Given what you know about each, which scientific division is likely to present the best answer to a question about how fluid dynamics affect blood pressure in mammals? A) Biochemistry –study of chemical reactions needed for life function, usually at the cellularlevel. B) Bioinformatics – use of technology to study and store biological data C) Biophysics – studyof biological processes through physics D) Biology – study of life
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4) Based on hierarchical levels of biological organization, which of these choices represents the broadest level? A) Endocrine system B) 3 toed sloths C) School of piranhas D) Amazon Basin E) Jaguars, giant anteaters, macaws,capybaras
5) Experiments are carried out to test a hypothesis by changing one variable at a time and should include an unchanged variable termed a(n)_________blank. A) experimentalvariable B) alteredvariable C) control D) stablevariable
6) The method of reasoning that uses construction of general principles by careful examination of many specific cases is called: A) deductive reasoning. B) theoretical reasoning. C) hypothetical reasoning. D) inductive reasoning. E) experimental reasoning.
7) Dr. Ratard was trying to determine the cause of a mysterious epidemic affecting fish in the Gulf of Mexico. His proposal that the deaths were caused by an organism called a protist is considered a(n)_________blank
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A) experiment. B) hypothesis. C) conclusion. D) theory. E) data set.
8) After Darwin concluded his voyage on the Beagle, he proposed that the process of natural selection was a mechanism for: A) artificial selection. B) evolution. C) sexual selection. D) speciation. E) overpopulation of finches on the Galapagos Islands.
9)
A scientific theory is:
A) a suggestedexplanation that accounts for observations. B) a way to organizehow we think about a problem. C) a concept that issupported by experimental evidence that explains the facts in an area ofstudy. D) a way to understanda complex system by reducing it to its working parts.
10)
What common life characteristic would cells from a daisy, bacteria, and a dog all have? A) DNA B) cell walls C) organs D) ability to conduct photosynthesis
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11) A yellow jacket, an insect in the order Hymenoptera, stung me. A wasp, an insect in Hymenoptera, stung me. A hornet, an insect in Hymenoptera, stung me. I see a pattern. All insects in this order must have stingers. What type of reasoning does this represent? A) inductivereasoning B) deductivereasoning C) reductionism D) comparativereasoning
12)
You explain to your study group that a hypothesis is: A) an explanation thataccounts for careful observations. B) a proposition thatwill be true and fits the known facts. C) a theory. D) constant overtime.
13) A suggested explanation that might be true and is subject to testing by further observations is a(n): A) experiment. B) generality. C) hypothesis. D) scientific principle. E) theory.
14) Based on the literature, you hypothesize that students in traditional biology lectures will have the same grades as students in online biology lectures. You decide to test your hypothesis by comparing grades of students in traditional and online biology lectures over a semester. As a result of the experiment, you observe that the grades in the traditional lectures and the grades in the online lectures are not significantly different. What do these observations allow you to do?
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A) reject thehypothesis B) modify the hypothesis to fit the results C) develop ascientific theory D) retain the hypothesis
15) Your microwave will not turn on, and you speculate that a circuit breaker in the house has been tripped. In scientific terminology, the steps would be described as: A) forming conclusions from the results of experiments. B) developing an observation based on a hypothesis. C) developing ahypothesis based on an observation. D) testing a prediction generated from a hypothesis.
16) A student poses the question: How does the presence of dissolved salt affect the freezing point of water? To answer this question, the student set up two conditions. In the first condition, the student added salt to water in a container and referred to this condition as the variable. In the second condition, the student did not add any salt to water in a second container and referred to this condition as the control. The student took both containers and attempted to freeze the water at various temperatures to assess the freezing point. Would this be a valid experiment? A) Yes, because there is more than one variable. B) Yes, because there is one variable and a control C) No, because there is not more than one variable D) No because thereis only one variable and a control
17) Karl Popper suggested that scientists use "imaginative preconception," which means that successful scientists:
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A) often predict the outcome of experiments. B) cannot predict the outcome of experiments. C) do not need to do experiments to test their ideas. D) do not keep records of experiments that fail. E) only perform applied research.
18) The proposal that one type of organism can change gradually into another type over a long period of time is known as: A) evolution. B) natural history. C) preconception. D) preservation.
19) Darwin's ideas on evolution were advanced for his time. His approach to science and natural selection were supported by what main tenet? A) Various organismsand their structures resulted from a spontaneous action. B) Species wereunchangeable over the course of time. C) The world is fixedand constant. D) Operation of natural laws produces constant change and improvement.
20) Besides Darwin, the theory of evolution by means of natural selection was also independently proposed by: A) Alfred Wallace. B) Charles Lyell. C) Thomas Malthus. D) Karl Popper. E) Peter Raven.
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21) The term that Darwin used to describe the concept that those with superior physical, behavior or other attributes are more likely to survive than those that are not so well endowed, and thus are more likely to pass their traits to the next generation, is called: A) biological diversity B) geometric progression C) natural selection D) superior beings E) survival of modifications
22) A key contribution to Darwin's thinking was the concept of limits put on the geometric growth of populations by nature, originally proposed by: A) Charles Lyell. B) Thomas Malthus. C) Karl Popper. D) Peter Raven. E) Russel Wallace.
23)
Darwin's book in which he described his views on evolution is: A) Principles of Geology. B) On the Principle of Population. C) On the Origin of Species. D) Survival of the Fittest.
24) Recent discoveries of microscopic fossils have extended the known history of life to about:
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A) 3.5billion years ago. B) 2 billion yearsago. C) 4.5billion years ago. D) 1 billion yearsago.
25) In California, a species of salamanders were geographically separated over time. The group that lived in southern California relied heavily on large gold blotches on their skin that helped to camouflage them from predators. The group that lived along the coast adopted a color pattern that mimicked a poisonous, colorful newt common to that area. Instead of being camouflaged, these salamanders advertised their colors. What type of selection process has occurred over time? A) artificialselection B) naturalselection C) experimentalselection D) theoreticalselection
26) The same basic array of bones is modified to give rise to the wing of a bat and the fin of a porpoise. Such anatomical structures are called: A) analogous. B) uniform. C) homologous. D) inherited. E) evolutionary modifications.
27) Structures that have similar structure and function but different evolutionary origins are called:
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A) homologous. B) analogous. C) inherited. D) uniform. E) evolutionary modifications.
28)
The rate at which evolution is occurring cannot be estimated by: A) studying comparative anatomy. B) inferring that apes are related to humans. C) measuring the degree of difference in genetic coding. D) interpretation of the fossil record.
29) Differences in domesticated animals over relatively short periods of time most likely occur through: A) natural selection B) adaptation C) evolution D) experimentalselection E) artificialselection
30) If you were to design a long-term research study to determine why there are no human births in Lapland during the months of August, September, and October, you would need to examine a comparison population of humans in which births took place every month. The primary reason for including a comparison population within the design of this experiment would be to:
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A) accumulate more facts that could be reported to other scientists. B) test the effects of more than one variable at the same time. C) prove that there are no births in Lapland during August, September, and October. D) act as a control to ensure that the results obtained are due to a difference in only one variable.
31) Essay on the Principle of Population, written by Thomas Malthus in 1798, influenced Darwin's thoughts as he struggled to understand what mechanisms could be at work to produce evolution. Malthus proposed that populations of animals and plants, including humans, A) increased arithmetically in numbers while the nutrients available only increased geometrically. B) increased geometrically in numbers while the nutrients available only increased arithmetically. C) decreased arithmetically in numbers while the nutrients available increased geometrically. D) evolved from islands to mainland, thus explaining why unrelated species on the mainland are found in the same location. E) evolved from mainland to islands, thus explaining why the island flora and fauna resembled the mainland species so closely.
32) A student set up an experiment to test if plants give off water vapor. Fifty pea plants, growing in pots, were covered with individual glass containers and left overnight. The next morning, the inside of each lid was covered in droplets of water. The lab student concluded that plants generally give off water vapor. What critique would you make of the experimental design? A) There was nocontrol so the water could have come from other sources such as air in the jaror the soil. B) There was not alarge enough sample of pea plants used to get adequate data. C) The student did nothave a clearly stated hypothesis before beginning the experiment. D) The experiment wasnot precise, meaning it was not reproducible.
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33) It is known that many trees lose their leaves in response to decreasing day length. As a result, you think that Gingko trees may also lose their leaves in response to decreasing day length. This statement is an example of: A) deductive reasoning B) an experiment C) a hypothesis D) a theory
34) Multiple independent experiments have demonstrated that phytochrome helps trigger seasonal change responses in planta such as changing color and losing leaves. Plants have the ability to adapt to seasonal changes in their surroundings. This statement is an example of: A) deductive reasoning B) an experiment C) a hypothesis D) inductive reasoning E) a theory
35) Plants are raised under artificial lights turned off and on by an electric clock. Some are given long periods of light, others short periods. This is an example of: A) deductive reasoning B) an experiment C) a hypothesis D) inductive reasoning E) a theory
36) Both walnut and Gingko trees lose their leaves in the fall when day length starts decreasing. Based on these observations one may conclude that many tree species will lose their leaves in the fall in response to decreasing day length. This statement is an example of:
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A) deductive reasoning B) an experiment C) inductive reasoning D) a theory
37) Gingko trees are known to lose their leaves at a certain time each year throughout the United States. Based on this information, Gingko trees in China must behave the same way. These statements are an example of: A) deductive reasoning B) an experiment C) inductivereasoning D) a theory
38) Most individuals in academia are basic researchers, funded through research grants from agencies or foundations. Based on your knowledge of applied research, an industrial company would most likely employ individuals A) who developalternative fuel sources. B) who identify a newspecies of beetle in the Amazon rainforest. C) looking at novelproteins involved in the development of a neurological disease. D) who documentfossils found in a specific archeological expedition.
39) Wings of birds and butterflies have similar functions, but different evolutionary origins. They are: A) homologousstructures. B) physiologicalstructures. C) phylogenetic structures. D) analogousstructures.
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40) An alien from another planet landed on earth. He is fascinated by cars and is determined to figure out how they work. He decides to disassemble one of them and examine each part independently. He removes one of the tires and proceeds to learn all he can about the tire. He then removes one of the headlights and proceeds to learn all he can about the headlight. What type of approach is this alien taking to learn about the car? A) reductionism B) deductive reasoning C) inductive reasoning D) Emergentproperties
41) While you are riding the ski lift up to the top of the mountain on a very cold day you start to shiver involuntarily. You know that the shivering is your bodyʹs attempt to help regulate your body temperature and is an example of what type of mechanism? A) energy utilization B) sensitivity C) homeostasis D) evolutionary adaptation
42) You have been assigned to address the problem of overpopulation of species X in a nearby county. One of the members of your team suggests introducing species Y, which is a natural predator of species X, but not normally found in the area. After some discussion, you go ahead and introduce species Y. What aspects of the hierarchical organization may be affected within a period of a several years? A) population, species, community B) population, community C) population, species, community, biosphere D) organism, population, species
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43) You have been assigned to analyze some extraterrestrial material recently collected from Mars. After examining a sample using a microscope you jump up excitedly and shout to your colleagues that you have confirmed the existence of life on Mars. One of your colleagues takes a look at your sample and remarks that all he sees is a single-celled "blob" with little internal structure. Assuming that life on Mars can be classified into similar domains and kingdoms as Earth, to which domain does your "blob" belong? A) Animalia B) Fungi C) Protista D) Archaea
44) Why was the determination of the actual sequence of the human genome considered to be descriptive science? A) It involved hypothesis-driven research. B) It did not involve hypothesis-driven research. C) It involved inductive reasoning. D) It did not involve deductive reasoning.
45) You look outside and realize that your grass needs to be mowed. You pick up the container of gasoline and see that you have approximately a third of a gallon left. You hypothesize that this amount will be enough to mow your entire lawn. Unfortunately, half way through mowing your lawn you run out of gasoline. You grumble and think to yourself that the next time you mow the lawn, you hypothesize that you will need to have at least two-thirds of a gallon of gasoline available. How did the results of your lawn-mowing experience influence the validity of your new hypothesis for future gasoline needs? A) Your prediction of future gas needs is based on experimental data and therefore increases the validity of your hypothesis. B) The hypothesis was invalidated by your experimental evidence. C) Your hypothesis was supported by trial and error. One more trial added to your data set. D) Your prediction proved that your hypothesis is correct.
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46)
Why is it necessary to take an interdisciplinary approach to studying biology?
A) Interdisciplinary approaches are required to answer all scientific questions since all disciplines borrow knowledge from each. B) Research methods used to solve many biological questions often require a number of different types of approaches and the expertise of a variety of scientists. C) Aninterdisciplinary approach is the only way we can further our biologicalknowledge.
47)
How does peer review influence the development of scientific theories?
A) Peer review allows other scientists to know what is current in their field. B) Careful evaluation of research results by other scientists ensures that only solid and legitimate research results are published, and helps prevent faulty research or false claims from being viewed as scientific fact. C) Peer review increases competition among scientists and thus increases the quality of the published work. D) Peer review makes it extremely difficult for work to be published other than earthshattering scientific theories.
48) Amanda was studying turtles based on DNA analysis. Under the current classification scheme, which of the following turtle species are thought to be most closely related? (1) Graptemys ouachitensis, (2) Trachemys scripta, (3) Apalone spinifera, (4) Graptemys kohni. A) 1 and 3 due to inductive reasoning B) 1 and 3 due to deductive reasoning C) 2 and 3 due to inductive reasoning D) 1 and 4 due toinductive reasoning E) 2 and 3 due to deductive reasoning F) 1 and 4 due to deductive reasoning
49) Marceau is studying small single-celled organisms that contain phospholipid membranes. These organisms can be broadly classified into the domain:
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A) Bacteria B) Protista C) Animalia D) Fungi
50) Bacterial cells are placed into a 250mL liquid growth medium in a closed laboratory flask. According to Malthusian theory, they will reproduce exponentially and then: A) continuereproducing geometrically as long as there are no limitations on foodsupply. B) continuereproducing arithmetically as long as there are no limitations on foodsupply. C) continuereproducing geometrically until the food supply is used up, then they willcease to grow. D) continuereproducing arithmetically until the food supply is used up, then they willcease to grow.
51) If two different species of fish fossils were found in two different layers of sedimentary rock, what might one infer about the specimens? A) They died at the same time B) The two species areunrelated C) The species in the higher layer evolved from the species in the lowerlayer D) The species inlower layer died first E) The species in the higher layer died first
52) A dental student wants to test if fluoride is an effective additive against tooth decay. The student studies tooth decay in a population of people who live in neighborhoods supplied with fluoridated water. This student would like to ask whether access to fluoridated water prevents tooth decay. What would be an effective control group to ask this question?
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A) Individuals withaccess to fluoridated water. B) Individuals withaccess to differing amounts of fluoride in the water. C) Individuals whohave fluoride added to their toothpaste but not their water. D) Individuals withaccess to water with no fluoride added.
53) Which statement represents the biological characteristics that kittens, oak trees, swans, earth worms, elephants and crickets have in common? A) DNA nucleotidesform the basis of all inherited life, with cells that are formed fromother cells. B) DNA nucleotidesform the basis of inherited life, with cells that are formed spontaneouslyfrom the environment. C) RNA nucleotidesform the basis of all inherited life, with cells that are formed fromother cells. D) RNA nucleotidesform the basis of inherited life, with cells that are formed spontaneouslyfrom the environment.
54) Viruses contain DNA or RNA, but lack genes necessary for metabolism and reproduction. Why are viruses not considered to be alive? A) Viruses are unable to reproduce independently of a host. B) Viruses do not contain nucleic acids. C) Viruses do not have the ability to evolve in their environment. D) Viruses do not contain internal organelles.
55) Osmometer cells in the brain sense an increase in the salt concentration of plasma. This information is sent to the hypothalamus, which notifies the pituitary gland to release the hormone, ADH. ADH causes the kidney to save water, which lowers the salt concentration of the plasma. What characteristic of life does this overall pathway represent?
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A) Cellularorganization B) Sensitivity C) Energyutilization D) Evolutionaryadaptation E) Homeostasis
56) A chemical imbalance in the blood can cause the heart to stop pumping blood, which will have a detrimental effect on other organs. This observation can be attributed to: A) Reductionism B) Emergentproperties C) Equilibrium state D) Evolutionary conservation
57) Dr. Edward Jenner realized that cows have a disease called cowpox, which is like a disease that infects humans called smallpox; Jenner noticed that milkmaids whose hands were infected with cowpox were not contracting smallpox. Jenner infected a child with the pus from a cowpox blister, and found that the child did not contract smallpox. Which statement represents a supporting hypothesis? A) The cowpox infection will prevent the child from being infected by the smallpox virus. B) The cowpox infection will have no effect on the child’s immunity to the smallpox virus. C) The smallpox virus was so similar to the cowpox virus that the child’s immune system recognized it and was able to fight it. D) The cowpox virus prevented the smallpox virus from entering the child’s immune system.
58) A beautiful wood desk you may do your homework on was once a living tree, but after being cut down its tissues died. Now, it only exhibits what property of life?
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A) Metabolism B) Homeostasis C) Sensitivity D) Organization
SECTION BREAK. Answer all the part questions. 59) As part of your research project, you travel to an island to learn more about the habitats and relationships of flies, spiders, and centipedes. You and your assistant plot out five different areas on the island and count the numbers of flies, spiders, and centipedes living in each plot. Your results show the following: Plot 1 2 3 4 5
59.1)
Flies Spiders 300 426 147 739 79
Centipedes 25 17 15 78 13
4 10 21 0 93
The most plausible explanation for the high number of spiders in plot 4 is:
A) there are too many flies overall. B) there are no centipedes to prey on the spiders and there are abundant flies upon which to feed. C) the spiders preyed on the centipedes and ignored the flies. D) the flies and spiders worked together to eliminate the centipedes.
59.2)
The plots that were staked out on the island were part of the:
A) appliedresearch. B) basic research. C) constructedmodel. D) experimental design.
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59.3) Based in the information provided, the best explanation for the low numbers of spiders and flies in plot 5 is: A) centipedes are actively consuming flies and spiders. B) there were not enough flies to support a large centipede population. C) centipedes prefer spiders to flies. D) there were not enough spiders to catch and consume all the flies.
59.4)
The hypothesis that closely matches the data provided is:
A) herbivorousinsects survive best on islands where spiders and centipedes live. B) herbivorousinsects feed on spiders and centipedes. C) herbivorousinsects and spider populations are decreased by centipedes. D) spiders are thetop predators on all islands.
60) McGraw-Hill Education
60.1) The common ancestor that produced the most evolutionary recent derived characters is
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A) 12 B) 9 C) 8 D) 6
60.2)
The species that have had proportionally the most time to diverge are:
A) R and D B) F and Z C) A and Z D) F and R E) F
61) Phil is conducting a seed germination experiment. He places 3 groups of lettuce seeds in a 34º Celsius incubator with adequate moisture. One set of seeds is placed in a dark area with no light source. A second set is placed under artificial light and third set of seeds is placed in direct sunlight. This experiment is intended to test Phil's hypothesis that light is necessary for lettuce seed germination.
61.1)
Based on the experimental design, which variable was the control?
A) Seeds in thedark B) Type of light C) Germinationrate D) Temperature E) Moisture
61.2)
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A) Seeds in thedark B) Type of light C) Germinationrate D) Temperature E) Moisture
62) Luke was taken to a pediatrician when he was 6 months old. The pediatrician consulted a graph and concluded that Luke was in the 97th percentile for height, weight and length. The pediatrician predicted that Luke would be tall when he reached adulthood.
62.1) What type of reasoning did the pediatrician use to generate her prediction about Luke’s future growth in height? A) Inductivereasoning B) Deductivereasoning C) Applied theory D) Reductionism
62.2) What type of logic is being used when the pediatrician uses the graph to make conclusions about Luke’s progress? A) Inductivereasoning B) Applied theory C) Reductionism D) Deductivereasoning
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63) Turtle hatchling survivorship rate is low in many turtle species due to predation. Amanda researched the predatory rate on a species of turtle eggs in the Red River. The eggs were harvested from trapped turtles and the egg's cloaca film (reproductive discharge) was either washed off or left on once gathered. Research suggests that predators use the female's cloaca scent to locate the eggs. The eggs were only handled when wearing gloves and then reburied along islands where the turtles were trapped. The nests were monitored by cameras and manually on foot and data on nest predation were recorded.
63.1)
Based on the experimental design, what is the dependent variable?
A) Number ofhatchlings B) Cloaca film oneggs C) Eggs without cloaca film D) Time eggs spent inground
63.2)
Based on the experimental design, what is the independent variable?
A) Number ofhatchlings B) Cloaca film on eggs C) Inducing egglaying D) Time eggs spent inground
63.3)
Based on the experimental design, what is the control?
A) Hatchling survivalrate B) Cloaca scent oneggs C) No cloaca scent oneggs D) Time eggs spent inground
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Answer Key Test name: Chap 01_13e_Raven 1) [C, D, F] 2) [A, B, D, E] 3) C
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Clarify Question What is the key concept addressed by the question? ● The question is about the differences between different divisions of biological research. What type of thinking is required? ● This question is asking for you to apply your understanding to identify which areas of research would focus on the movement of fluids. What key words does the question contain and what do they mean? ● Fluid dynamics: refers to the physics of how fluids (liquids) move. Gather Content What do you know about different divisions of biology?How does it relate to the question? ● Bioinformatics is the study of biological data like sequences using computers ● Biology is a very broad area of research covering all areas of the study of life ● Biochemistry is the study of biological molecules smaller than a cell ● Biophysics is the study of how biological molecules move using the laws of physics Consider Possibilities What other information is related to the question? Which information is most useful? ● The study of the movement of fluids like blood are not sequence or structural data and not biological molecules, thus bioinformatics and biochemistry are not good answers. ● Biology is a very broad heading, and not the best answer. Choose Answer Version 1
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Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● The best answer is biophysics because the movement of fluids are well described using the laws of physics. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply the definitions different areas of biology to determine which might study fluid dynamics. ● If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that fluid dynamics were part of a cell or represented by large data sets? Did you not know that the movement of fluids was an area of study in physics? 4) D 5) C 6) D 7) B 8) B 9) C 10) A 11) A 12) A 13) C 14) D
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Clarify Question What is the key concept addressed by the question? ● The question is about hypotheses. What type of thinking is required? ● This question is asking to apply your knowledge of a hypothesis to interpret the results of an experiment. What key words does the question contain and what do they mean? ● Scientific theory: a well-tested, accepted principle or body of knowledge. ● Hypothesis: a theory that can be modified, but must be retested based on new predictions. Gather Content What do you know about hypotheses?How does it relate to the question? ● Hypotheses that are supported by results are retained. ● Hypothesis that are inconsistent with the results are rejected. ● A hypothesis can be modified and the modified version re-tested. Consider Possibilities What other information is related to the question? Which information is most useful? ● You hypothesize that students in traditional biology lectures will have the same grades as students in online biology lectures ● The grades in the traditional lectures and the grades in the online lectures are not significantly different Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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● Because the results support your hypothesis, you do not reject the hypothesis. A scientific theory cannot be developed from the results of one experiment. A hypothesis for an experiment must be formulated independent of the results. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply the definition of a hypothesis to a specific example. ● If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that you can develop a scientific theory based on the results of one experiment? Did you think that the results were inconsistent with your hypothesis? 15) C 16) B 17) A 18) A 19) D 20) A 21) C 22) B 23) C 24) A 25) B
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Clarify Question What is the key concept addressed by the question? ● The question is about different forms of selection. What type of thinking is required? ● This question is asking you to apply the definition of different forms of selection to a specific example. What keywords does the question contain and what do they mean? ● Geographic separation: members of two or more populations can no longer interbreed which can drive the evolution of new species. Gather Content What do you know about selection? How does it relate to the question? ● Selection works on the phenotype of an organism, with beneficial traits being more likely to be passed on to the next generation. Consider Possibilities What other information is related to the question? Which information is most useful? ● Artificial selection requires humans to be involved to make the selection. ● Theoretical and experimental selection are part of an experiment. The selection in this example did not involve humans or any experiments. Choose Answer Given what you now know, what information and/or problem-solving approach is most likely to produce the correct answer? ● This is an example of natural selection due to geographic separation. Once the two groups of salamanders became separated they could no longer interbreed and developed different adaptations to their local environments. ● One group of salamanders hides by being camouflaged while the other has bright colors that mimic another poisonous species. Version 1
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply the definitions selection to a specific example. ● If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that natural selection would not occur with geographical separation, or that humans were involved in the speciation in some way? 26) C 27) B 28) B 29) E 30) D 31) B 32) A
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Clarify Question What is the key concept addressed by the question? ● The question is about designing an experiment. What type of thinking is required? ● This question is asking to analyze the design of an experiment. What key words does the question contain and what do they mean? ● Not applicable Gather Content What do you know about experimental design? How does it relate to the question? ● The hypothesis is that plants give off water vapor. There are 50 pots each containing plants (the test) were covered with lids. The next day each pot contained water vapor. ● The weakness of this experiment is that it does not contain a control group, so you cannot conclude that the water came from the plants or from the soil or other components of the experiment. Consider Possibilities What other information is related to the question? Which information is most useful? ● Are there other explanations for these results? 50 plants is a large sample size, there was a hypothesis and the experiment was carried out correctly. So you can eliminate these as answers. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● The best answer is there was no appropriate control group. Half of the pots should have been prepared with no plants in them to be sure the Version 1
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water vapor was not coming from the soil or pots. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply the definitions of deductive and inductive reasoning to specific examples. ● If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you not realize that all of the pots contained a plant? While the hypothesis was not clearly stated, you could infer it from the first sentence of the problem. Did you think that 50 plants was too small a sample? 33) A 34) E 35) B 36) C 37) A 38) A 39) D 40) A
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Clarify Question What is the key concept addressed by the question? ● The question is about different types reasoning. What type of thinking is required? ● Apply the definitions of different types of reasoning to a specific example. What key words does the question contain and what do they mean? ● Inductive reasoning: uses data to create a hypothesis ● Deductive reasoning: draws conclusions from existing observations or definitions ● Reductionism: breaking down something into its component parts to study them individually Gather Content What do you know about different types of reasoning? How does it relate to the question? ● The key concept here is that the alien is breaking down the car to figure out how each part works independently. Consider Possibilities What other information is related to the question? Which information is most useful? ● What are other types of reasoning? Is a hypothesis being tested or data analyzed? If not, then this is not an example of inductive or deductive reasoning. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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● Without data or a hypothesis, breaking down an object to be studied is a reductionist method Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply the definitions of reductionist reasoning to a specific example. ● If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you forget the definitions of deductive and inductive reasoning? Did you not realize the that taking something apart to figure out how it works is reductionism? 41) C 42) A
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Clarify Question What is the key concept addressed by the question? ● The question is about the impact of a new species on the hierarchical organization of living systems. What type of thinking is required? ● Applying the definition of levels of organization to determine how they are affected by addition of a new species. What key words does the question contain and what do they mean? ● Y is a predator of X. This means that Y eats X. ● Population: members of a species in a local area ● Species: all members of a species ● Community: multiple species interacting with each other ● Biosphere: both living and non-living components Gather Content What do you know about hierarchical organization?How does it relate to the question? ● Heirarchical refers to one level building on the level below it, like a pyramid. So if one level is affected it can impact the levels above it. Consider Possibilities What other information is related to the question? Which information is most useful? ● If a predator is added which levels of structure would be affected? A predator would impact the prey species at the population level. Levels above this would also be affected up to the level of community. Choose Answer Given what you now know, what information and/or problem solving Version 1
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approach is most likely to produce the correct answer? ● The best answer that the population of X will be affected, which in turn affects the species and the community that it belongs to. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to predict the impact of a predator on different levels of a hierarchical system. ● If you got the correct answer, great job! If you got an incorrect answer, where did you get stuck? A decrease in the number of species X would affect the hierarchical levels above it up to the community level. Increased predation will not have an impact at the level of an individual organism or the biosphere. 43) D
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Clarify Question What is the key concept addressed by the question? ● The question asks you to determining the domain of a new organism. What type of thinking is required? ● Apply the criteria of different domains to specific examples. What key words does the question contain and what do they mean? ● Single celled: the entire organism contains only one cell. ● Internal structure: organelles, such as the nucleus. Gather Content What do you know about different domains? How does it relate to the question? ● Protista and fungi both have single celled members, but have internal structures. ● Animals are all multicellular and have internal structures. ● Archaea are like bacteria, are single celled, and do not have internal structures. Consider Possibilities What other information is related to the question? Which information is most useful? ● If the only clue was single celled which could be correct? Protista and fungi both have single celled members, animals are all multicellular. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● All members of the domain Archaea are single celled and do not have internal structures, so this is the best answer.
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply the characteristics of different domains to specific examples to classify an unknown organism. ● If you got the correct answer, great job! If you got an incorrect answer, where did you get stuck? While three of the domains listed have single celled organisms, only one lacks internal structures. 44) B 45) A 46) B 47) B 48) D
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Clarify Question What is the key concept addressed by the question? ● The question is about the differences between inductive and deductive reasoning. What type of thinking is required? ● This question is asking for you to apply the definition of inductive and deductive reasoning to specific examples. What key words does the question contain and what do they mean? ● DNA analysis: sequencing the DNA from individuals and comparing the similarity of the sequences. The more closely related the species, the more similar their DNA sequences will be. ● Genus and species names are given. Closely related species will have the same genus. Gather Content What do you know about relatedness based on species names? How does it relate to the question? ● There are two parts of a species name and those with the same genus are the most closely related. Consider Possibilities What other information is related to the question? Which information is most useful? ● In which examples are general principles being used and in which are specific results being considered? ● In inductive reasoning there are data to analyze to create a hypothesis. In deductive reasoning you make conclusions or predictions from existing data or observations Choose Answer Version 1
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Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● Data (DNA sequences) are being analyzed to draw conclusions, so this is inductive reasoning. The two turtle species with the same genus should have the most similarity in their DNA sequences. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply the definition of inductive reasoning to a specific example and also to recognize that two species of the same genus will be more closely related. ● If you got the correct answer, great job! If you got an incorrect answer, where did you get stuck? Did you not realize that the two species of turtles from the same genus would be closely related? Did you not recognize that analyzing DNA sequences to draw a conclusion was inductive reasoning? 49) A 50) C 51) D
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Clarify Question What is the key concept addressed by the question? ● The question is about the formation of fossils. What type of thinking is required? ● This question is asking you to apply the principles of fossil formation to interpret data. What key words does the question contain and what do they mean? ● Fossils: can be found at different layers of sedimentary rock. Gather Content What do you know about relatedness based on location in a rock layer? How does it relate to the question? ● Sedimentary rock forms when sediment (silt and sand) drops to the bottom of a lake or ocean, covering whatever is on the bottom of the lake or ocean. In general when fossils are found in different layers, the older fossils are found at the bottom. Consider Possibilities What other information is related to the question? Which information is most useful? ● In sedimentary rock the upper layers are newer. Whether or not the two different species are related does not impact what layer they are found in, and you also cannot assume that one evolved from the other. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● Sediments form at the bottom of a lake and accumulate over time. Thus the older fossils are in the older layer and these organisms died Version 1
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before those in the upper layer. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply your understanding of fossil formation to predict the relative age of different fossils. ● If you got the correct answer, great job! If you got an incorrect answer, where did you get stuck? Did you recall that as sedimentary rock forms it traps dead animals that can then become fossils? 52) D
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Clarify Question What is the key concept addressed by the question? ● The question is about designing an experiment. What type of thinking is required? ● This question is asking you to apply you knowledge to identify an appropriate control for the experiment. What key words does the question contain and what do they mean? ● Hypothesis: in this case, to test the effectiveness of fluoride in the water on preventing tooth decay. Gather Content What do you know about experimental design? How does it relate to the question? ● The neighborhood being tested already has fluoride in the water. If you want to see if fluoride is effective in preventing tooth decay you need a control group with no fluoride to compare it with. Consider Possibilities What other information is related to the question? Which information is most useful? ● What are other explanations for these results? Adding any fluoride to the water would not be a good control group. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● The best control would be a group of individuals with no fluoride in their water. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply your understanding of a hypothesis to identify the proper control group for an experiment. ● If you got the correct answer, great job! If you got an incorrect answer, where did you get stuck? Did you realize that fluoride is your independent variable, this is the variable the researcher can control? Did you realize that adding any fluoride to the water of the control group would make it more difficult to test your hypothesis? 53) A 54) A 55) E 56) B 57) A 58) D
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Clarify Question What is the key concept addressed by the question? ● The question is about identifying different properties of life. What type of thinking is required? ● Applying the definitions of the properties of life. What key words does the question contain and what do they mean? ● Wood: tissue from a living tree. ● Properties of life: 1.Homeostasis: keeping things in balance, requires energy 2.Sensitivity: nerve signals require energy 3.Organization: requires energy to establish, but can be maintained after death 4.Metabolism: extraction of energy from food Gather Content What are the properties of life after the trees death? How do they relate to the question? ● Wood is the tissue that was formed when the tree was alive and remains after death of the tree. Consider Possibilities What other information is related to the question? Which information is most useful? ● Homeostasis, sensitivity and metabolism all require that an organism be alive. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● While organization requires energy to become established, it can Version 1
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remain after the death of an organism. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply your understanding of the properties of life to specific examples. ● If you got the correct answer, great job! If you got an incorrect answer, where did you get stuck? A tree still has structure after it dies from its cell walls. The other answers all require the organism to still be alive. 59) Section Break 59.1) B
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Clarify Question What is the key concept addressed by the question? ● The question is about a food web. What type of thinking is required? ● This question is asking to analyze data on a food web. What key words does the question contain and what do they mean? ● Flies: prey for spiders ● Spiders: prey for centipedes and predators of flies ● Centipedes: predators of flies and spiders Gather Content What do you know about food webs?How does it relate to the question? ● In a food web an organism will often be prey for some species and a predator of others. As a result, the abundance of prey and/or predators can influence the numbers of a specific species. Consider Possibilities What other information is related to the question? Which information is most useful? ● If flies are at the bottom of the food web, they will not consume other species and only serve as a food supply. ● Spiders are in the middle of the food web and their numbers are influenced by the levels of prey (flies) and predators (centipedes). ● Centipedes are the top predators in this food web and their numbers can be affected by the abundance of prey (flies and spiders).
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Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● The best answer is that there are a lot of flies (prey) and few predators (centipedes) which leads to an abundance of spiders. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to analyze data on a food web to draw specific explanations for the results. To do this you needed to recognize which species were predators and which were prey. ● If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that flies were not at the bottom of the food web, or centipedes were not at the top of the food web? 59.2) D 59.3) A
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Clarify Question What is the key concept addressed by the question? ● The question is about a food web, specifically why flies and spiders are less abundant. What type of thinking is required? ● This question is asking to evaluate explanations about a food web. What key words does the question contain and what do they mean? ● Flies: prey for spiders ● Spiders: prey for centipedes and predators of flies ● Centipedes: predators of flies and spiders Gather Content What do you know about food webs?How does it relate to the question? ● In a food web an organism will often be prey for some species and a predator of others. As a result the abundance of prey and/or predators can influence the numbers of a specific species. Consider Possibilities What other information is related to the question? Which information is most useful? ● Both spiders and flies are decreased in number, while centipedes are increased in plot 5. ● If centipedes preferred spiders over flies then the numbers of flies would be more similar to those in plots 1-4. ● The centipede population is larger than in the other plots, so there must have been enough flies to support them. ● If there were not enough spiders to consume all of the flies then Version 1
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the number of flies would be increased. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● Which food webs would be consistent with these results? The best answer is that the abundant centipedes ate a lot of flies and spiders, reducing their number in plot 5. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply the definitions of deductive and inductive reasoning to specific examples. ● If you got the correct answer, great job! If you got an incorrect answer, where did the process break down?Did you think that flies were not at the bottom of the food web, or centipedes were not at the top of the food web? 59.4) C 60) Section Break 60.1) D
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Clarify Question What is the key concept addressed by the question? ● The question is about interpreting phylogenetic trees. What type of thinking is required? ● This question is asking for you to apply the principles of a phylogenetic tree to infer relatedness. What key words does the question contain and what do they mean? ● Evolutionary recent derived characterists: traits that related species have. Evolutionary recent means that they happened more recently than other shared traits. Gather Content What do you know about relatedness based on a phylogenetic tree?How does it relate to the question? ● The Y axis measures time, the longer the line, the more time since the living species at the end of either branch shared a common ancestor. ● The nodes or branch points refer to recent common ancestors. Consider Possibilities What other information is related to the question? Which information is most useful? ● Which lines are the shortest? The lines between species R and D and their most recent common ancestor are the shortest and occurred most recently. ● The other pairs of species all have more distant common ancestors based on the lengths of the lines. Choose Answer Version 1
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Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● R and D have the most recent common ancestor and this ancestor is indicated by branch point 6. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply your understanding of a phylogenetic tree to determine recent ancestors. ● If you got the correct answer, great job! If you got an incorrect answer, where did you get stuck? Did you realize that the Y axis (vertical) represents time and the numbers at the branch points represent common ancestors? 60.2) B
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Clarify Question What is the key concept addressed by the question? ● The question is about interpreting phylogenetic trees. What type of thinking is required? ● This question is asking for you to apply the principles of a phylogenetic tree to infer the most distant common ancestor. What key words does the question contain and what do they mean? ● Time to diverge: the most time elapsed since the species had a common ancestor. Gather Content What do you know about relatedness based on a phylogenetic tree? How does it relate to the question? ● The Y-axis reflects the amount of time since two species had a common ancestor. The common ancestors are indicated by the branch points. Consider Possibilities What other information is related to the question? Which information is most useful? ● Which lines connecting two species are the longest? R and D have a common ancestor at branch point 6, this is the shortest of the links between two species. So these species had the shortest time to diverge. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● Using the logic above, the two species with the longest time to Version 1
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diverge are F and Z with a common ancestor at branch point 12. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply your understanding of a phylogenetic tree to determine which species had the most time to diverge. ● If you got the correct answer, great job! If you got an incorrect answer, where did you get stuck? Did you realize that the Y axis (vertical) represents time and the numbers at the branch points represent common ancestors? 61) Section Break 61.1) A
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Clarify Question What is the key concept addressed by the question? ● The question is about designing an experiment. What type of thinking is required? ● This question is asking you to apply your knowledge of experimental design to identify an appropriate control for the experiment. What key words does the question contain and what do they mean? ● Hypothesis: in this case, that light is necessary for seed germination. Gather Content What do you know about experimental design? How does it relate to the question? ● Seeds were placed in three conditions: in the dark, artificial light and direct sunlight. Consider Possibilities What other information is related to the question? Which information is most useful? ● Which of the three groups is the control? If you are testing to see if light is necessary for germination then the two conditions exposing seeds to light are not good control groups. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● The seeds in the dark are the control group. The other two groups are receiving some kind of light, and this is the hypothesis that is Version 1
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being tested, so these seeds are in the test or experimental group. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply your understanding of experimental design to identify the correct control group for an experiment. ● If you got the correct answer, great job! If you got an incorrect answer, where did you get stuck? A control group is what you are comparing your test groups to. Were you confused that the hypothesis being tested was that light was required for germination? 61.2) C
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Clarify Question What is the key concept addressed by the question? ● The question is about designing an experiment. What type of thinking is required? ● This question asks you to apply the definition of dependent variable to identify it in an experiment. What key words does the question contain and what do they mean? ● Dependent variable: the variable that the researchers are measuring. Gather Content What do you know about dependent variables? How does it relate to the question? ● This is what the researcher is measuring after making changes in the independent variable. Consider Possibilities What other information is related to the question? Which information is most useful? ● Moisture and temperature were kept constant and were controlled variables. ● The amount of light was the independent variable the researcher changed. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● The variable being measured was the rate of seed germination, so this is the dependent variable. Version 1
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● The amount of light was being changed by the experimenter, so light is the independent variable. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply your understanding of experimental design to identify the correct dependant variable for an experiment. ● If you got the correct answer, great job! If you got an incorrect answer, where did you get stuck? Did you recall that the dependent variable is dependent on changes in the independent variable? In this example the amount of germination (dependent variable) was affected by the amount of light (independent variable). 62) Section Break 62.1) A
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Clarify Question What is the key concept addressed by the question? ● The question is about different types reasoning. What type of thinking is required? ● Applying the definitions of different types of reasoning to a specific example. What key words does the question contain and what do they mean? ● Applied theory: using a theory to solve a problem ● Reductionism: breaking something into its parts and studying each part individually ● Inductive reasoning: using data to draw a conclusion ● Deductive reasoning: using an existing theory or definition to draw a conclusion Gather Content What do you know about different types of reasoning?How does it relate to the question? ● Data was being analyzed and used to make a prediction. Consider Possibilities What other information is related to the question? Which information is most useful? ● Deductive reasoning uses a definition or theory to draw conclusions. ● Reductionism breaks an object into pieces to study how each piece works independently. Choose Answer
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Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● Inductive reasoning uses data to make a prediction, so this is the correct answer. The doctor was measuring Luke’s current height and using it to predict his future growth. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply the definition of inductive reasoning to a specific example. ● If you got the correct answer, great job! If you got an incorrect answer, where did you get stuck? Did you forget that a specific prediction or hypothesis based on data is called inductive reasoning? Or did you forget that deductive reasoning is based on creating a general hypothesis from existing data or definitions? 62.2) D
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Clarify Question What is the key concept addressed by the question? ● The question is about different types reasoning. What type of thinking is required? ● Applying the definitions of different types of reasoning to a specific example. What key words does the question contain and what do they mean? ● Applied theory: using a theory to solve a problem ● Reductionism: breaking something into its parts and studying each part individually ● Inductive reasoning: using data to draw a conclusion ● Deductive reasoning: using an existing theory or definition to draw a conclusion Gather Content What do you know about different types of reasoning? How does it relate to the question? ● A definition or theory is used to draw conclusions in deductive reasoning. Consider Possibilities What other information is related to the question? Which information is most useful? ● Inductive reasoning analyzes data to make a prediction. ● Reductionism breaks an object into pieces to study how each piece works independently. Choose Answer
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Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● As an existing graph of percentile weight and length was used, this is deductive reasoning. ● Based on Luke’s current height the doctor could make a prediction about Luke’s height in the future. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply the definition of inductive reasoning to a specific example. ● If you got the correct answer, great job! If you got an incorrect answer, where did you get stuck? Did you forget that using a chart or table to make a prediction is deductive reasoning? 63) Section Break 63.1) A
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Clarify Question What is the key concept addressed by the question? ● The question is asking about designing an experiment. What type of thinking is required? ● This question is asking you to apply the definition of the dependent variable and identify it in an experiment. What key words does the question contain and what do they mean? ● Cloaca: a thin film on eggs. Predators may use its scent to locate the eggs. ● Dependent variable: this is what the researcher is measuring to see if it changes when the independent variable is changed. Gather Content What do you know about dependent variables? How does it relate to the question? ● The dependent variable is the variable the researcher measures. Consider Possibilities What other information is related to the question? Which information is most useful? ● The independent variable is the variable that the researcher changes, in this case the presence or absence of cloaca. ● Control variables are held constant, in this case the time spent in the ground. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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● The dependent variable is the number of hatchlings. This is what the researchers are measuring to see if the presence of cloaca affects predation of the eggs. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply your understanding of experimental design to identify the dependent variable in an experiment. ● If you got the correct answer, great job! If you got an incorrect answer, where did you get stuck? Did you recall that the dependent variable is dependent on changes in the independent variable? In this case the number of hatchlings is dependent on the presence or absence of cloaca. 63.2) B
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Clarify Question What is the key concept addressed by the question? ● The question is about designing an experiment. What type of thinking is required? ● This question is asking you to apply the definition of the independent variable to identify it in an experiment. What key words does the question contain and what do they mean? ● The eggs were harvested from trapped turtles and the egg's cloaca film (reproductive discharge) was either washed off or left on once gathered. Gather Content What do you know about controls? How does it relate to the question? ● This is what the researcher compares their test samples to. Consider Possibilities What other information is related to the question? Which information is most useful? ● The dependent variable is the variable that the researcher measures, in this case the number of hatchlings. ● Control variables are held constant, in this case the time spent in the ground. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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● The independent variable is the presence or absence of cloaca on the eggs. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply your understanding of experimental design to identify the independent variable in an experiment. ● If you got the correct answer, great job! If you got an incorrect answer, where did you get stuck? Did you recall that the dependent variable is dependent on changes in the independent variable? In this case the number of hatchlings is dependent on the presence or absence of cloaca. 63.3) B
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Clarify Question What is the key concept addressed by the question? ● The question is about designing an experiment. What type of thinking is required? ● This question is asking you to identify the control group of an experiment by definition. What key words does the question contain and what do they mean? ● Control group: the group in which the researcher keeps the independent variable constant. In other groups the independent variable is changed and compared to the control. Gather Content What do you know about control groups? How does it relate to the question? ● The control group is what you compare the test group to by changing the independent variable. Consider Possibilities What other information is related to the question? Which information is most useful? ● The independent variable is the variable that the researcher changes, in this case the presence or absence of cloaca. ● The dependent variable is the variable that the researcher measures, in this case the number of hatchlings. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● The control group are the turtle eggs that did not have their cloaca Version 1
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wiped off. The rate of hatching can then be compared to the rate of hatching in eggs with their cloaca wiped off. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply your understanding of experimental design to identify the correct control group for an experiment. ● If you got the correct answer, great job! If you got an incorrect answer, where did you get stuck? Did you confuse the control with the dependent and independent variables? Which eggs were not altered by the researcher in the experiment?
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Chapter 02 13e MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 1) Matter is composed of: A) atoms B) energy C) mass D) molecules
2)
The number of protons in a given atom is equal to its: A) atomic number B) mass C) neutron number D) molecularnumber
3) Isotopes that are unstable and decay when their nucleus breaks up into elements with lower atomic numbers, and emit significant amounts of energy in the process, are called: A) energetic B) ionic C) radioactive D) isometric
4)
Atoms containing a specific number of protons are called: A) minerals B) elements C) metals D) molecules
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5)
Sugar dissolves completely in water because of water's ______. A) ionic bonds B) cohesiveness C) hydrophobicexclusion D) polarity
6)
The negative logarithm of the hydrogen ion concentration in a solution is referred to as: A) pH B) atomic mass C) -OHconcentration D) electronegativity E) specific heat
7) Bicarbonate ions in the blood can absorb hydrogen ions, keeping the pH balanced. Bicarbonate acts as a ____ in blood. A) buffer B) acid C) base D) alkaline
8)
Atomic nuclei contain protons and _______. A) isomers B) ions C) moles D) neutrons
9)
Carbon-12, Carbon-13 and Carbon-14 are examples of:
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A) ions B) isotopes C) isomers D) molecules
10)
Organisms are composed of molecules, which are collections of smaller units, termed: A) monomers. B) atoms. C) electrons. D) polymers. E) ions.
11)
Negatively charged subatomic particles that have almost no mass are called: A) electrons. B) protons. C) neutrons. D) ions. E) polymers.
12)
Atoms of a single element that possess different numbers of neutrons are called: A) polymers. B) ions. C) monomers. D) isomers. E) isotopes.
13)
Cl + e- → Cl- is an example of a:
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A) oxidation. B) reduction. C) polymerization. D) ionization.
14) When atoms gain or lose electrons, they can become negatively or positively charged. These charged atoms are known as: A) isotopes. B) ions. C) isomers. D) unstableatoms.
15)
When two atoms share a pair of electrons, this bonding is referred to as: A) ionic. B) covalent. C) unstable. D) hydrogen.
16) Water molecules are polar, with regions that exhibit partial positive or negative charges. These opposite charges allow water molecules to attract each other via: A) ionic bonds. B) covalent bonds. C) hydrogen bonds. D) peptide bonds.
17) An atom has 20 electrons and 20 neutrons. Assume it has a net charge of zero. What is the total mass of this atom?
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A) 10 B) 20 C) 40 D) 80
18) Sanai was monitoring the oil spill in the Gulf of Mexico from an oil tanker. From her observations, she noted that the oil was moving in large patches through the water. The oil did not appear to dissolve into the water. Why did the oil not dissolve into the water? A) Hydrophobicinteractions B) Surface tension C) Sea water acts as asolvent D) Water formshydration shells E) Water has a high heat ofvaporization
19)
The atomic number of an element is equal to the number of: A) protons only. B) neutrons only. C) protons plus electrons. D) protons plus neutrons. E) neutrons plus electrons.
20) Oxygen has an atomic mass of 16 and an atomic number of 8. How many neutrons are present? A) 24 B) 8 C) 16 D) 4
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21) <p>The pH of your small intestines is around 7.5 and the pH of your large intestine can be 5.5. As substances travel from the small intestines to the large intestine, what would happen to the ion concentration? A) It decreases 100-fold. B) It increases by 100-fold. C) It increases 10-fold. D) It increases 2-fold. E) It decreases 10-fold.
22) Oxygen-16 is abundant in the environment and has 8 protons and 8 neutrons. Oxygen-18 has two extra neutrons. These two forms of oxygen are: A) oxygen ions. B) oxygenisotopes. C) oxygen isomers. D) oxygen dimers.
23) Which element's isotope is commonly used to determine when biological samples such as fossils were formed? A) oxygen B) hydrogen C) carbon D) nitrogen E) sulfur
24) A type of atom where the number of electrons does not equal the number of protons is also referred to as:
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A) valences. B) ions. C) isotopes. D) isomers.
25)
The area around a nucleus where an electron is most likely to be found is the: A) electrical space. B) energy level. C) polar space. D) orbital.
26)
Regardless of its shape, a given orbital may contain no more than: A) 1 electron. B) 4 electrons. C) 8 electrons. D) 2 electrons.
27) All atoms tend to fill their outer energy levels with the maximum number of electrons, usually eight. Depending on whether atoms satisfy the octet rule, this will predict: A) the chemicalbehavior of the atoms. B) whether they willbe found in nature. C) whether they will dissolve in water. D) their radioactive energy.
28) Mendeleev found that when he arranged the known elements according to their atomic mass, the entries in the table exhibited a pattern of chemical properties that repeated itself in groups of eight elements. This led to the generalization now known as:
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A) an atomic model. B) valanceelectrons. C) the periodictable. D) the octetrule.
29) Sodium has 11 electrons arranged in three energy levels. In order to become stable, sodium forms an ion that contains: A) no charge. B) -1 charge. C) -8 charge. D) +1 charge. E) +8 charge.
30)
In the crystal matrix of ordinary salt, the sodium and chlorine are held together by: A) peptide bonds. B) covalent bonds. C) ionic bonds. D) hydrogen bonds. E) nonpolar bonds.
31) Two oxygen atoms bind to each other by sharing two pairs of electrons. This molecule forms a(n): A) single bond. B) ionic bond. C) hydrogen bond. D) double covalentbond.
32) In a chemical analysis of a sample of animal tissue, which element would you expect to find in the least quantity?
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A) carbon B) hydrogen C) nitrogen D) oxygen E) iodine
33) Life is thought to have evolved from complex molecules formed by the interaction of smaller molecules in the oceans and atmosphere. The substance which brought these molecules together to interact is: A) hydrogen. B) acids. C) water. D) buffers. E) salts.
34)
Because oxygen is more electronegative than hydrogen, the water molecule is: A) hydrophobic. B) hydrophilic. C) nonpolar. D) ionic. E) polar.
35) Water molecules are attracted to each other due to the opposite charges created by partial charge separations within the molecules. These attractions are called: A) peptide bonds. B) covalent bonds. C) ionic bonds. D) hydrogen bonds. E) double bonds.
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36)
How many hydrogen bonds can a water molecule form? A) 1 B) 2 C) 3 D) 4 E) 5
37) Nitrogen has a higher electronegativity than hydrogen. As a result you would expect that ammonia (NH3) molecules can form ____ with each other. A) hydrogen bonds B) hydrophilicbonds C) ionic bonds D) covalent bonds E) cohesive bonds
38) When water ionizes, it produces equal amounts of hydrogen and hydroxide ions that can reassociate with each other. The pH of water is: A) 3 B) 4 C) 5 D) 6 E) 7
39) A scientist conducts a procedure that causes nitrogen atoms to gain neutrons. The resulting atoms will be:
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A) ions of nitrogen. B) positively charged. C) negatively charged. D) isotopes of nitrogen. E) new elements with higher atomic numbers.
40) The half-life of Carbon-14 is approximately 5,700 years. Using this information scientists have been able to determine the age of some artifacts left by humans. A scientist wants to know approximately how old a piece of wood is that she found on the floor in an old cave that had recently been discovered. She removed the wood (with permission) and took it to her laboratory. Her wood sample contained 2 grams of Carbon-14. If the age of the wood was determined to be 22,800 years old, how much Carbon-14 originally existed in this piece of wood? A) 32 grams B) 16 grams C) 12 grams D) 8 grams E) 4 grams
41) Plants transport water to their leaves through the xylem when water evaporates from the leaves. The evaporating water pulls other water molecules up the xylem by means of ____ . A) hydrogen bonds B) ionic bonds C) covalent bonds D) hydrophobic interactions
42) Water is most dense and thus heaviest at 4°C. At 0°C, ice forms and can float on liquid water. Suppose ice was more dense then water at 0°C. What would happen in a lake at this temperature?
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A) The ice wouldcover the surface of the aquatic system and would never melt. B) The ice wouldcover the bottom of the aquatic system and would build up in layers overtime. C) Ice would not formbecause solids are always less dense than liquids. D) The cold temperatures and the subsequent ice formation would prevent hydrogen bonds from forming between the water molecules, thus causing the existing ice crystals to become disassociated from each other.
43) Your dog becomes ill and you rush him to the veterinarian's office. A technician draws blood from your dog's leg for a vet-ordered lab test. After a few minutes the lab results are given to the vet, who immediately grabs a bottle from a shelf and begins to fill a syringe with an unknown fluid. You inquire about the fluid, and the vet informs you that the fluid is necessary to manage your dog's metabolic acidosis. Based on the information provided, what is acidosis, and what is the likely effect of the veterinarian's injection? A) Acidosis means thatyour dog's blood pH has dropped from its normal level, and an injection ofsaline is required to reverse the condition. B) Acidosis means thatyour dog's blood pH has increased from its normal level, and an injection ofsaline is required to reverse the condition. C) Acidosis means thatyour dog's blood pH has decreased from its normal level, and an injection ofbuffering solution is required to reverse the condition. D) Acidosis means thatyour dog's blood pH has increased from its normal level, and an injection ofbuffering solution is required to reverse the condition.
44) As you and a friend are entering a chemistry laboratory at your university, you see a sign that states: DANGER—RADIOACTIVE ISOTOPES IN USE. Your friend is an accounting major and has not had any science courses yet. She asks you what a radioactive isotope is and you respond correctly with:
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A) Radioactiveisotopes are atoms that are unstable and as a result emit energy in a processcalled radioactive decay. B) Radioactiveisotopes are atoms that are stable and as a result emit energy in a processcalled radioactive decay. C) Radioactiveisotopes are atoms that are stable and as a result only emit energy if they areexposed to higher temperatures. D) Radioactive isotopes are atoms that are unstable but unless actively disturbed by some chemical process will remain intact and pose no problems.
45)
To increase the rate of a reaction you could: A) Add more products. B) Decrease thetemperature. C) Add more reactants. D) remove a catlyst
46)
The two nitrogen atoms in nitrogen gas (N2) share six electrons forming a _____. A) triple covalentbond B) double covalentbond C) single covalentbond D) hydrogen bond E) double bond
47) Capillary action is one of the forces that aids water's upward movement in plants. The narrower the diameter of the tube, the farther the water column will rise. Capillary action is a result of water molecules:
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A) storing heat and thus moving faster because of heat of vaporization. B) producing sufficient surface tension to overcome the pull of gravity. C) having a strong cohesive force and attaching to the surrounding vessel walls. D) having an adhesive force, which allows them to attach to the vessel walls. E) being associated with hydrophobic molecules, which can result in upward movement.
48)
Which atomic particle has no charge and is located in the nucleus? A) electron B) ion C) neutron D) proton E) isotope
49)
A subatomic particle with a positive charge is _____. A) an electron B) an ion C) a neutron D) a proton E) an isotope
50)
The smallest subatomic particle is the ______. A) electron B) ion C) isotope D) neutron E) proton
51)
An atom that becomes negatively charged because it has accepted an electron is a(n):
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A) isomer. B) ion. C) isotope. D) monomer.
52) One mole of a substance contains 6.02 x 1023 molecules. The atomic number of Li is 3 and the atomic mass is approximately 7. If you have three moles of Li, how many grams does it weigh? A) 9 B) 21 C) 7 x 6.02 x 1023 D) 3 x 6.02 x 1023
53) After taking your biology exam, you return to your car to find that you had left the lights on and now the car battery is dead. Your friend offers to jump-start your car, but when you go to hook up the jumper cables you find that the battery terminals are covered with corrosion due to battery acid condensation. Based off your knowledge, what substance could be used to clean the corrosion? A) coffee (pH of5) B) water (pH of 7) C) vinegar (pH of3) D) baking soda (pH of9)
54)
The amino acid glycine (C3NO2H6) is a(n): A) organicmolecule B) inorganicmolecule C) element D) vitamin
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55) Consider the following electronegativity values: Boron (B) = 1.8 Carbon (C) = 2.5 Chlorine (Cl) = 3.2 Selenium (Se) = 2.6 Which of the following bonds is the most polar? A) B-Cl B) C-Cl C) Se-Cl D) It cannot be determined from the information provided.
56) The reaction (H2 + F2 → 2HF) is an example of a redox reaction. In reality, two half reactions are occurring. The half reaction (H2 → 2H+ + 2e-) is a(n): A) reduction reaction B) oxidation reaction C) redox reaction D) potential energy reaction
57) The electronic configuration of the noble gas Neon, which has an atomic number of 10, can be written as follows: 1s22s22p6. What is the electronic configuration of the noble gas Argon, which has an atomic number of 18? A) 1s22s23p64s25p6 B) 1s22s62p23s63p2 C) 1s22s22p63s23p6 D) 1s22s83p8
58) You identify an enzyme involved in a cellular reaction. How does the enzyme affect the reaction equilibrium between reactants and products and the time needed to reach equilibrium?
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A) It alters the reaction equilibrium and shortens the time needed to reach equilibrium. B) The reaction equilibrium is unaffected, but it shortens the time needed to reach equilibrium. C) It alters the reaction equilibrium and lengthens the time needed to reach equilibrium. D) The reaction equilibrium is unaffected, but it lengthens the time needed to reach equilibrium.
59) You walk down into your basement to find that the carpeting on the floor is damp. Concerned, you look around for large puddles of water or broken pipes, but find none. In fact, only the basement floor and carpeting is damp. You realize that water must have wicked into the carpet from the floor by ______. A) adhesion and cohesion B) adhesion and solubility C) adhesion, cohesion,and solubility D) cohesion and solubility
60) You recently discovered a new element, and find that this particular element has one electron in its outer energy level. What do you expect will happen to an atom of this element if placed in water? A) It will lose an electron forming a positive ion. B) It will lose anelectron forming a negative ion. C) It will gain an electron forming a positive ion. D) It will gain anelectron forming a negative ion.
61)
Why is it necessary to take special safety precautions when using radioactive materials? A) Radioactive substances will ionize cells. B) Radioactive substances have the potential to cause damage to living cells. C) Radioactive substances decay. D) Radioactive substances will perforate plasma membranes.
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62) The high heat of vaporization of water helps you to feel cooler when you sweat because the transition of water from a liquid to a gas requires a ______ of energy to break hydrogen bonds. The energy is _____ from heat produced by your body, thus helping to lower the surface temperature of your body. A) release;released B) release;obtained C) input;obtained D) input; released
63) Salt is often used to melt ice on roads during the winter because it lowers the freezing/melting point of water. When salt dissolves in water, individual Na+ and Cl- ions break away from the salt lattice and become surrounded by water molecules. Why would this cause ice to melt? A) Hydrogen bondsare broken, and the salt ions interfere with interactions between H and O. As aresult, it is more difficult for water molecules to bond and form ice. B) Hydrogen bonds are formed, and the salt ions bond with O. As a result, it is more difficult for water molecules to bond and form ice. C) Hydrogen bonds are broken, and the salt ions bond with O and H respectively. As a result, it is more difficult for water molecules to bond and form ice.
64) A chemist adds a chemical to pure water and there is a 100-fold increase in the concentration of hydrogen ions. What is the best approximation of the new pH value? A) 0 B) 5 C) 7 D) 9 E) 14
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65) The electronegativity of nitrogen (N) is 3.0, while the electronegativity of hydrogen (H) is 2.1. Knowing this, consider how the electrons will be shared in ammonia (NH3). What do you predict about the polarity of ammonia? A) Each H atom has a partial positive charge B) The N atom has a partial positive charge C) Each H atom has a partial negative charge D) The N atom has astrong positive charge
66) Magnesium chloride (MgCl2) is a salt formed with ionic bonds between one magnesium ion and two chloride ions. Magnesium has two electrons in its outer shell and chlorine has seven electrons in its outer shell. How are the electrons transferred between these atoms? A) Both magnesium and chlorine are reduced. B) Both magnesium and chlorine are oxidized. C) Chlorine is oxidized and magnesium is reduced. D) Magnesium is oxidized and chlorine is reduced.
67) Carbonic acid and bicarbonate buffer in blood are extremely important to help maintain homeostasis. What would happen to the pH of the blood if bicarbonate were removed? A) Removingbicarbonate from the blood would increase the pH B) Removingbicarbonate from the blood would decrease the pH C) Removingbicarbonate from the blood would not affect the pH
68) The common basilisk lizard will run across water on its hind legs in an erect position when startled by predators. This lizard has large feet and flaps of skin along its toes. What properties of water allow this lizard to walk on water?
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A) Hydrogen bondsabsorb heat when they break and release heat when they form. This helps tominimize temperature changes. B) The surface tension created by hydrogen bonds is greater than the weight of the lizard initially. C) Polar molecules areattracted to ions and polar compounds, making these compounds soluble. D) Hydrogen bonds hold water moleculestogether; many hydrogen bonds must be broken for water to evaporate.
69)
How is the bond in F2 different from the bond in KCl? A) F2 iscovalent and KCl is ionic B) F2 andKCl are both ionic C) F2 isionic and KCl is covalent
70)
Carbon has 4 valence electrons and oxygen has 6. Carbon dioxide would contain _____. A) one single covalent bond B) four hydrogen bonds C) two double covalent bonds D) two single covalent bonds
71) If water were nonpolar it would not form hydrogen bonds. At normal room temperature this nonpolar water would be _____. A) a gas B) a liquid C) a solid
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72) Proteins are three dimensional molecules made from strands of amino acids (imagine a string of beads). There are 20 different amino acids that can be used in proteins found in living organisms. Some of these amino acids are polar and others are nonpolar. In the watery cytosol of a cell, the protein folds into the three dimensional structure. Where would a series of nonpolar amino acids most likely be located in a protein that is found in the cytosol of an animal cell? A) On the surface of the protein B) In the interior ofthe protein C) At the very top ofthe protein D) At the very bottom of the protein
73) According to most car mechanics, plain water is the best coolant to use in an engine provided the engine is not being exposed to freezing temperatures. If the car is subject to freezing temperatures then a mixture of water and ethylene glycol (antifreeze) is recommended but it does not cool as efficiently as plain water. Why would ethylene glycol reduce the cooling efficiency of water? A) Ethylene glycolhas a lower heat capacity than water. B) Ethylene glycolhas a higher heat capacity than water. C) Hydrogen bonds inwater allow high levels of heat absorption and a large increase intemperature. D) Ethylene glycolraises the freezing point of water.
74) Dennis had a history of heart disease in his family and was reducing his intake of saturated fats. Saturated means each carbon atom is bonded to as many hydrogen atoms as it can accept. If a carbon were bonded to two carbons, how many hydrogens could it accept? A) 0 B) 1 C) 2 D) 3 E) 4
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Answer Key Test name: Chap 02_13e_Raven 1) A 2) A 3) C 4) B 5) D 6) A 7) A 8) D 9) B 10) B 11) A 12) E 13) B 14) B 15) B 16) C 17) C
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Clarify Question • What is the key concept addressed by the question? The question asks about calculating the mass of an atom. • What type of thinking is required? You are being asked to apply the definition of atomic mass to calculate the atomic mass. • What key words does the question contain and what do they mean? o Atomic mass is the sum of the masses of protons and neutrons in a single atom. We assume the mass of electrons is so small it doesn’t contribute to total mass. Gather Content • What do you know about atomic mass? How does it relate to the question? o The masses of a single proton and single neutron are both 1 each. Consider Possibilities • What other information is related to the question? Which information is most useful? o There are 20 protons and 20 neutrons, each with a mass of 1 within this atom. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o 20 protons + 20 neutrons = an atomic mass of 40. Reflect on Process Version 1
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the definition of atomic mass to calculate an atomic mass. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you confuse atomic number (the number of protons alone) with the atomic mass (the sum of protons and neutrons)? 18) A
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Clarify Question • What is the key concept addressed by the question? The question asks why oil and water don’t mix. • What type of thinking is required? You are being asked to apply your knowledge of the properties of water and oil, in order to explain why the oil did not dissolve in water. • What key words does the question contain and what do they mean? o Dissolve: when one compound mixes completely with a solvent, like water. Gather Content • What do you know about water as a solvent? How does it relate to the question? o Water is a polar molecule, meaning other polar molecules or ions will dissolve in it. These water loving molecules are called hydrophilic. o Oil is a nonpolar molecule and will dissolve better in a nonpolar solvent. These molecules are called hydrophobic, or water fearing. Consider Possibilities • What other information is related to the question? Which information is most useful? o Water is a solvent with a high heat of vaporization and also forms surface tension. However, none of these properties explain why oil does not dissolve in water. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The best answer is that oil is hydrophobic, meaning it does not interact well with water. This is because water is a polar molecule and oil is nonpolar. Water has -O-H bonds which do not share electrons equally and give O a partial negative charge and H a partial positive charge. In contrast, oil is made up of -C-H bonds where the electrons are shared more equally, leading to no partial charges. Because oil does not have these charges it is not attracted to the charges in water, and thus does not dissolve well in water. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the properties of water to explain why oil and water do not mix well. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you know what the word hydrophobic meant? Did you have difficulty remembering which properties of water make it a good solvent for other polar molecules? 19) A 20) B
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Clarify Question • What is the key concept addressed by the question? The question asks you to calculate the number of neutrons from the atomic mass and number of an atom. • What type of thinking is required? You are being asked to apply your knowledge of how atomic mass and atomic number are calculated. • What key words does the question contain and what do they mean? o Atomic mass: the number of neutrons plus protons in an atom. o Atomic number: the number of protons in an atom. Gather Content • What do you know about the number of neutrons in an atom? How does it relate to the question? o Atomic mass refers to the combinded number of neutrons and protons in an atom. Consider Possibilities • What other information is related to the question? Which information is most useful? o Atomic number is defined by the number of protons in an atom. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o To calculate the number simply take atomic mass (P + N) and subtract the atomic number (P). o In this example: 16 – 8 = 8 neutrons Version 1
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the structure of an atom to predict some of its properties. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you know the definitions of how atomic mass and atomic numbers? Did you have difficulty figuring out how to calculate the number of neutrons by subtracting the atomic number from the atomic mass? 21) B
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Clarify Question • What is the key concept addressed by the question? The question asks about relating pH to H+ concentration. • What type of thinking is required? You are being asked to apply the definition of pH to a specific example. • What key words does the question contain and what do they mean? o pH: this is calculated as –log[H+] Gather Content • What do you know about the link between H+ concentration and pH? How does it relate to the question? o Because the relationship between H+ concentration and pH is on a log scale, a change in pH of 1 corresponds to a change in H+ concentration by 10-fold. o Because the relationship is calculated as negative, an increase in pH of 1 means there is a decrease in H+ concentration by 10-fold. Consider Possibilities • What other information is related to the question? Which information is most useful? o When moving from the small intestines to the large intestines, the pH goes from 7.5 to 5.5, which means the substance is moving to a more acidic environment. This means that the H+ concentration will increase. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Because the pH drops by 2 pH units, the H+ concentration will increase by 10x10 or 102 = 100 fold. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the definition of pH to calculate H+ concentration. If you got Version 1
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the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that pH is on a log scale? Did you recall that pH has a negative relationship to H+ concentration, so an increase in pH leads to a decrease in H+ concentration?
22) B 23) C 24) B 25) D 26) D 27) A 28) D 29) D
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Clarify Question • What is the key concept addressed by the question? The question asks about predicting an atom's ionic form. • What type of thinking is required? You are being asked to apply your knowledge of the structure of an atom to predict ion formation. • What key words does the question contain and what do they mean? o Energy levels: the first level holds 2 electrons and each higher level holds 8 electrons. Gather Content • What do you know about the structure of atoms? How does it relate to the question? o If you make an electron diagram of the structure of a sodium atom, there are 2 electrons in the first shell, 8 in the second shell and 1 in the outer (valence) shell. Consider Possibilities • What other information is related to the question? Which information is most useful? o If there is one valence electron then the atom could lose that electron or gain 7 more to have a full outer shell (octet). Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The atom will lose its single valence electron, losing the -1 charge carried by the electron. This will give the Na ion a +1 charge. Version 1
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the structure of an atom to predict if it will form an ion. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you have trouble drawing the structure of a sodium ion? Did you recognize that the sodium atom would lose an electron to have a stable outer shell? 30) C 31) D 32) E 33) C 34) E 35) D 36) D
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Clarify Question • What is the key concept addressed by the question? The question asks about the formation of hydrogen bonds in water. • What type of thinking is required? You are being asked to apply your knowledge of the structure of water to predict the formation of hydrogen bonds. • What key words does the question contain and what do they mean? o Hydrogen bonds: weak ionic interactions between a partial positive charge on one atom/molecule and a partial negative charge on another atom/molecule. o Water has the structure H-O-H Gather Content • What do you know about hydrogen bonds? How does it relate to the question? o Oxygen has a stronger attraction for electrons than hydrogen and ends up with two partial negative charges. o Hydrogen has a weaker attraction for electrons than oxygen and ends up with a partial positive charge. o Hydrogen bonds will form between the H atom on one water molecule and the O atom on a second water molecule. Consider Possibilities • What other information is related to the question? Which information is most useful?
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o Each H atom can form one hydrogen bond with an O atom on another water molecule. o Each O atom can form hydrogen bonds with two H atoms on other water molecules. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Water can form hydrogen bonds with 4 water molecules. Two bonds will be through the H atoms and two through the O atom. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to interpret the structure of a water molecule to predict how many hydrogen bonds it could form. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Could you draw the structure of a water molecule? Could you identify which atoms would be involved in forming a hydrogen bond? 37) A
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Clarify Question • What is the key concept addressed by the question? The question asks about electronegativity. • What type of thinking is required? You are being asked to apply your knowledge of electronegativity to predict what types of bonds a molecule could form. • What key words does the question contain and what do they mean? o Electronegativity: the pull of an atom on an electron. Gather Content • What do you know about electronegativity? How does it relate to the question? o Nitrogen has a higher electronegativity than hydrogen. This means that the nitrogen atoms will have a partial negative charge and the hydrogen atoms will have a partial positive charge. Consider Possibilities • What other information is related to the question? Which information is most useful? o The partial charges on N and H atoms on adjacent NH3 molecules will be attracted to each other. o These are not covalent bonds which share electrons. o These are partial charges, so they are not ionic bonds. o Because these are charged they are hydrophilic and not hydrophobic. Choose Answer • Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer? o The best answer is that the attraction through partial charges is a hydrogen bond between the N on one NH3 and the H on another. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to interpret the structure of a molecule to predict some of its properties. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Could you draw the structure of an NH3 molecule? Did you realize how hydrogen bonds form? 38) E 39) D 40) A
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Clarify Question • What is the key concept addressed by the question? The question asks about radioactive carbon. • What type of thinking is required? You are being asked to analyze data on radioactive decay. • What key words does the question contain and what do they mean? o Half-life: the amount of time in which half of a dose of radioactivity in a sample will be lost to decay. Gather Content • What do you know about half life? How does it relate to the question? o The first step is to figure out how many half-lives have occurred: 22,800 ÷ 5,700 = 4. Consider Possibilities • What other information is related to the question? Which information is most useful? o 4 half-lives means the amount of radiation will have been cut in half 4 times. o 2x2x2x2 = 24 = 16, which means that the total amount of radiation will have decreased by 16-fold. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o 2 grams of Carbon-14 remain, and this represents the amount left after Version 1
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a 16-fold decrease. This means the original amount should be 2 grams x 16 = 32 grams. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze radioactive decay and calculate the original amount of radioactive carbon from a sample. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that the amount of sample would be cut in half with each decay? One common misconception is to think that 4 rounds of decay would decrease the radioactivity 4-fold. Each round cuts the amount of radioactivity in half, so this leads to a 16-fold decrease. 41) A
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Clarify Question • What is the key concept addressed by the question? The question asks about attraction interactions between water molecules. • What type of thinking is required? You are being asked to apply your knowledge about the properties of water. • What key words does the question contain and what do they mean? o Ionic bonds: a full positive charge on one molecule attracted to a full negative charge on another molecule o Hydrophobic interactions: hydrophobic groups repel water and clump together o Hydrogen bonds: a partial negative charge on one atom is attracted to a partial positive charge on another atom. One of these atoms would be a hydrogen atom. o Covalent bonds: when two atoms share a pair of electrons Gather Content • What do you know about the properties of water? How does it relate to the question? o Water is a polar molecule with partial negative charges on oxygen atoms and partial positive charges on hydrogen atoms. Consider Possibilities • What other information is related to the question? Which information is most useful? o Covalent bonds form between atoms within the same molecule. The question refers to interactions between water molecules, so these cannot be covalent. o Ionic bonds involve full charges, while water has partial charges. o Hydrophobic interactions are found in non-polar molecules, and water Version 1
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is polar. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The best answer is that hydrogen bonds form between water molecules. As one water molecule evaporates it pulls the next water molecule up, moving water through the xylem. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply principles of hydrogen bonding to the properties of water. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall the structure of water and types of bonds it forms? 42) B
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Clarify Question • What is the key concept addressed by the question? The question asks about the properties of liquid water and ice. • What type of thinking is required? You are being asked to apply your knowledge of the relative densities of liquid water and ice to what happens in a lake in the winter. • What key words does the question contain and what do they mean? o Density: this is the measure of mass/volume. Gather Content • What do you know about ice? How does it relate to the question? o Because ice has a more rigid structure than liquid water it occupies more volume. Thus the same mass of liquid water and ice vary in their density. Because liquid water occupies less volume it has a larger density than ice. This is why ice floats on top of liquid water. Consider Possibilities • What other information is related to the question? Which information is most useful? o As with many molecules, solids are denser than liquids. The question asks you to predict what would happen if ice was denser than liquid water. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If ice were denser than water it would sink to the bottom of a lake Version 1
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during the winter. Over time the ice would fill in the lake from the bottom up, eventually freezing everything in the lake. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the properties of water to predict what would happen if ice was denser than water. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize that if ice was denser than liquid water it would sink? The density would not affect water's ability to form or break hydrogen bonds. 43) C
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Clarify Question • What is the key concept addressed by the question? The question asks about the treatment of acidosis. • What type of thinking is required? You are being asked to apply your knowledge of acids to explain how acidosis is treated. • What key words does the question contain and what do they mean? o Acidosis: when the blood is more acidic. o Buffers: solutions used to adjust the pH of a solution. o Saline: a salt solution with the same osmolarity of blood. Gather Content • What do you know about acids and buffers? How does it relate to the question? o Acids will lower the pH of a solution. o Buffers can be used to neutralize acids. Consider Possibilities • What other information is related to the question? Which information is most useful? o Saline is a salt solution and will not affect pH. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If your dog has acidosis then the pH of his blood is too low. A buffer will be used to neutralize the acid and raise the pH back to a healthy level. Version 1
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the properties of a buffer to neutralize an acid. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that acids will lower pH? Did you recall that buffers will neutralize pH? 44) A 45) C 46) A
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Clarify Question • What is the key concept addressed by the question? The question asks about the formation of covalent bonds. • What type of thinking is required? You are being asked to apply your knowledge of covalent bonds to predict how many bonds are present in N2. • What key words does the question contain and what do they mean? o Covalent bonds: when two atoms share a pair of electrons Gather Content • What do you know about covalent bonds? How does it relate to the question? o Two atoms share a pair of electrons to form a covalent bond. o Atoms can form more than one covalent bond. Consider Possibilities • What other information is related to the question? Which information is most useful? o If the two N atoms are sharing 6 electrons, and there are 2 electrons shared in one covalent bond, then there are 6 ÷ 2 = 3 covalent bonds. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o There are 3 covalent bonds between the two N atoms in N2. Reflect on Process • Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze the structure of a covalent bond to predict the number formed in N2. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize that a covalent bond contains 2 shared electrons? Did you realize that two atoms can have more than one covalent bond? 47) D 48) C 49) D 50) A 51) B 52) B
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Clarify Question • What is the key concept addressed by the question? The question asks about calculating the mass of 3 moles of Li. • What type of thinking is required? You are being asked to apply the atomic mass of a compound to calculate the mass of 3 moles. • What key words does the question contain and what do they mean? o Atomic mass: the mass (in grams) of one mole of an element o Atomic number: the number of protons in an atom o 6.02 x 1023 atoms/mole: this is defined as Avagadro’s number, and is universal for each atom. Gather Content • What do you know about converting from moles to mass? How does it relate to the question? o If you have 3 moles of Li, you will want to multiply that by a factor with the units 'grams/mole' so the moles unit cancels and you are left with grams. Consider Possibilities • What other information is related to the question? Which information is most useful? o Atomic number has the units protons/atom and won’t be useful in calculating grams. o Avagadro’s number has the units atoms/mole and won’t be useful in calculating grams. Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Atomic mass has the units grams/mole. o 3 moles of Li x 7 grams/mole = 21 grams of Li Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the concept of moles and atomic mass to calculate the mass of 3 moles of Li. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall the units for atomic mass, atomic number, and Avagadro’s number? Were you able to set up the calculation properly? 53) D
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Clarify Question • What is the key concept addressed by the question? The question asks about pH. • What type of thinking is required? You are being asked to apply your knowledge of pH to neutralize an acid. • What key words does the question contain and what do they mean? o Acid: solution with a pH less than 7. o Base: solution with a pH greater than 7 Gather Content • What do you know about acids? How does it relate to the question? o Acids have a pH less than 7, so to neutralize the acid you would want to use a base (solution with a pH greater than 7). Consider Possibilities • What other information is related to the question? Which information is most useful? o Water is neutral (pH 7) and will not neutralize an acid. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The only base on the list of answers is baking soda (pH 9). Adding a base with a high pH will neutralize an acid with a low pH. Reflect on Process
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the definition of an acid to neutralize an acid. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that acids have a low pH? Did you realize that a base with a high pH would neutralize an acid? 54) A 55) A
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Clarify Question • What is the key concept addressed by the question? The question asks about the link between electronegativity and polar bonds. • What type of thinking is required? You are being asked to analyze the relative electronegativities of two atoms in a bond to predict which would be most polar. • What key words does the question contain and what do they mean? o Electronegativity: the attraction of an atom for an electron. o Polar bond: a covalent bond in which the electrons are not shared equally. Gather Content • What do you know about polar bonds? How does it relate to the question? o The greater the difference in electronegativity between two atoms in a covalent bond, the more polar the bond will be. Consider Possibilities • What other information is related to the question? Which information is most useful? o To calculate the relative polarity of the bonds, simply subtract the electronegativities of each atom in the bond. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o Se-Cl: 3.2-2.6 = 0.6 o C-Cl: 3.2-2.5 = 0.7 o B-Cl: 3.2-1.8 = 1.4 o The largest difference is between B and Cl, so the B-Cl bond will be the most polar with Cl pulling the electrons away from B. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the definition of electronegativity to predict the polarity of a covalent bond. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you know what electronegativity and polar bonds were? Did you know how to compare the difference in electronegativity between the two atoms to determine the polarity of the bond? 56) B
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Clarify Question • What is the key concept addressed by the question? The question asks about redox reactions. • What type of thinking is required? You are being asked to apply the definition of reactions that lose an electron. • What key words does the question contain and what do they mean? o Redox reaction: contains an oxidation and a reduction reaction. o Oxidation: reaction involving a loss of an electron(s) (the charge of the atom or molecule losing the electron is oxidized) o Reduction: reaction involving a gain of an electron(s) (the charge of the atom or molecule gaining the electron is reduced) Gather Content • What do you know about redox reactions? How does it relate to the question? o In a redox reaction electron(s) are transferred from one atom or molecule to another. o This is made up of an oxidation half reaction where the electrons are lost by one reactant, and a reduction half reaction where the electrons are gained by the second reactant. Consider Possibilities • What other information is related to the question? Which information is most useful? o In the half reaction H2 → 2H+ + 2e-, H2 is losing 2 electrons Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Because H2 is losing 2 electrons this is an oxidation half reaction. o This would be balanced by the reduction half reaction F2 + 2e- → 2Fo Finally the 2H+ + 2F-→ 2HF o Putting this all together you get the reaction: H2+ F2→ 2HF Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the definition of an oxidation reaction. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you have trouble recognizing that an oxidation half reaction was being shown? Did the mention of a redox reaction confuse the problem for you? 57) C
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Clarify Question • What is the key concept addressed by the question? The question asks about the configuration of electrons in an atom. • What type of thinking is required? You are being asked to apply your knowledge of electron configuration to create one for Argon. • What key words does the question contain and what do they mean? o Electron configuration: the occupancy of electrons in different shells. o Atomic number: the number of protons in an atom, and thus also the number of electrons. Gather Content • What do you know about electron configuration? How does it relate to the question? o The first shell contains 2 electrons in an “s” orbital. A full first shell is represented by 1s2 . o The next shells each contain 8 electrons: 2 electrons in an “s” orbital and 6 electrons in a “p” orbital. A full second shell is represented by 2s22p6. Consider Possibilities • What other information is related to the question? Which information is most useful? o Argon has an atomic number 18 and Neon is 10. Thus Argon has 8 more electrons than Neon, which adds one more shell. Choose Answer • Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer? o Adding a third shell to Neon will add 8 more electrons, 2 electrons in an “s” orbital and 6 electrons in a “p” orbital. o Following the same numbering as with Neon this would add 2s22p6. o The complete electron configuration for Argon will be 1s22s22p63s23p6. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the orbitals of electrons in an atom to write an electron configuration. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you have trouble understanding what was being represented in the numbering system of an electron configuration? Did you realize that the 8 electrons in shells 2 and 3 were split between “s” and “p” orbitals? 58) B 59) A
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Clarify Question • What is the key concept addressed by the question? The question asks about properties of water. • What type of thinking is required? You are being asked to apply your understanding of properties of water to explain an observation. • What key words does the question contain and what do they mean? o Wicked: this means the water moved upward, in this case from the floor to the carpet Gather Content • What do you know about properties of water? How does it relate to the question? o Water is a polar molecule that forms hydrogen bonds with other water molecules and polar compounds. This allows water to move upward by wicking. Consider Possibilities • What other information is related to the question? Which information is most useful? o Adhesion: water sticking to other molecules through hydrogen bonds. o Cohesion: water molecules sticking to each other. o Solubility: substances dissolving in water. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Both adhesion and cohesion will allow water molecules to bind to Version 1
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polar molecules in the carpet and wick upward from the floor. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the properties of water to explain wicking. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall the definitions of adhesion, cohesion, and solubility? 60) A
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Clarify Question • What is the key concept addressed by the question? The question asks about the formation of ions. • What type of thinking is required? You are being asked to apply your knowledge of electron energy levels to the formation of ions. • What key words does the question contain and what do they mean? o Outer energy level: an atom is most stable when its outer energy level is full. Also called a valance shell. Gather Content • What do you know about ions? How does it relate to the question? o To be most stable, an atom may gain or lose electrons to end up with a full outer shell of electrons. Consider Possibilities • What other information is related to the question? Which information is most useful? o This atom has one extra electron in its outer shell. o If it gains an electron it will still have a partially full outer shell (2 electrons). o If the atom loses an electron it will have a full outer shell (8 electrons). Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Losing an electron will give the atom a full outer shell. Version 1
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o Because an electron has a -1 charge, losing the electron will give the atom a +1 charge, forming a positive ion. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze the structure of an atom to predict the formation of its ion. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize that the atom would be most stable if it lost an electron? Did you recognize that losing an electron would lead to the formation of a positively charged ion? 61) B 62) C 63) A
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Clarify Question • What is the key concept addressed by the question? The question asks how salt would prevent ice from forming. • What type of thinking is required? You are being asked to apply your knowledge of the properties of water to explain how salt melts ice. • What key words does the question contain and what do they mean? o Freezing point: the temperature below which water molecules hydrogen bond to each other in a solid lattice commonly known as ice Gather Content • What do you know about ice? How does it relate to the question? o Ice forms because the water molecules are in a 3-dimensional lattice with each water molecule hydrogen bonded to 4 other water molecules. Consider Possibilities • What other information is related to the question? Which information is most useful? o When salt dissolves in water the NaCl dissociates into Na+ and Clions. Each of these ions interact with water molecules. The Na+ will be attracted to the partial negative charge on O in water and the Cl- ions will be attracted to the partial positive charge on H in water. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Because Na+ and Cl- ions interact with water molecules through the partial charges on water, this interferes with the ability of water Version 1
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molecules to hydrogen bond with each other. o Because water molecules can no longer form hydrogen bonds with each other, they cannot form a lattice and ice does not form. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the properties of water to explain why salt melts ice. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize that ice forms because of hydrogen bonding between water molecules? Did you understand that salt ions interfere with this hydrogen bonding, reducing water’s ability to form ice? 64) B
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Clarify Question • What is the key concept addressed by the question? The question asks about the relationship between pH and hydrogen ion concentration. • What type of thinking is required? You are being asked to apply your knowledge of pH to predict what would happen to water when the hydrogen ion concentration is increased. • What key words does the question contain and what do they mean? o pH: this is from the formula, pH= –log[H+] Gather Content • What do you know about pH? How does it relate to the question? o Because pH is the –log[H+], as the H+ concentration goes up the pH goes down. o Because it is a log scale, each 10-fold change in H+ concentration results in a change in pH of 1. o In this case, a 100-fold increase in H+ concentration would lead to a decrease in pH of 2. Consider Possibilities • What other information is related to the question? Which information is most useful? o Next we need to figure out what the pH was before the chemical was added to water. Pure water has a pH of 7. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o Pure water has a pH of 7 and the chemical dropped the pH by 2, so the new pH will be about 5. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the definition of pH to predict what would happen if a chemical was added that raised the H+ concentration. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you have trouble using the equation of pH? Did you recall that there is a negative log relationship between pH and H+ concentration, so the pH decreases? Did you recall that the pH of water is 7? 65) A
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Clarify Question • What is the key concept addressed by the question? The question asks about electronegativity. • What type of thinking is required? You are being asked to apply your knowledge of electronegativity to predict the effect of partial charge on an atom. • What key words does the question contain and what do they mean? o Electronegativity: the attraction of an atom for an electron. o Partial charges: if two atoms in a covalent bond have different attractions for an electron, this is called a polar covalent bond. o The atom with the stronger attraction will have a partial negative charge and the atom with the weaker attraction will have a partial positive charge. Gather Content • What do you know about electronegativity? How does it relate to the question? o The electronegativity of N is 3.0 and that of H is 2.1. o N has a stronger attraction for the electrons in its covalent bond with H. Consider Possibilities • What other information is related to the question? Which information is most useful? o Because electrons have a negative charge, the N will have a partial negative charge.
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Based on the same logic, each H atom will have a partial positive charge as the electrons are pulled towards N. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the definition of electronegativity to predict the partial charges on atoms in a polar covalent bond. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recognize that the higher electronegativity on N meant it had more attraction for electrons than H? Did you realize that a stronger pull for electrons gave N a partial negative charge, while this led to a partial positive charge on each H? 66) D
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Clarify Question • What is the key concept addressed by the question? The question asks about reduction and oxidation reactions. • What type of thinking is required? You are being asked to apply your knowledge on the formation of ions through reduction and oxidation. • What key words does the question contain and what do they mean? o Outer shell of electrons: an atom is most stable with a full outer shell of electrons. This can be obtained by gaining or losing electrons. Gather Content • What do you know about oxidations and reductions? How does it relate to the question? o If an atom loses an electron it becomes oxidized and forms a positive charge. o If an atom gains an electron it becomes reduced and forms a negative charge. Consider Possibilities • What other information is related to the question? Which information is most useful? o Mg has 2 extra electrons in its outer shell, so it will be most stable losing two electrons. o Cl has 7 electrons in its outer shell, so it will be most stable gaining one electron. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Mg will lose two electrons, forming Mg2+ and becoming oxidized in the process. o Cl will gain one electron, forming Cl- and becoming reduced in the process. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the structure of an atom to predict if it would become reduced or oxidized in forming an ion. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize that Mg would lose electrons and Cl would gain them? Did you remember that oxidations lose electrons and reductions gain electrons? 67) B
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Clarify Question • What is the key concept addressed by the question? The question asks about buffers. • What type of thinking is required? You are being asked to apply your knowledge of buffers to predict what would happen if a base was removed. • What key words does the question contain and what do they mean? o Carbonic acid: this is the acid of the buffer. o Bicarbonate: this is the base of the buffer. Gather Content • What do you know about buffers? How does it relate to the question? o Buffers contain a weak acid and its complementary base. o Acids lower the pH of a solution and bases raise the pH. Consider Possibilities • What other information is related to the question? Which information is most useful? o If the bicarbonate was removed from the solution all that would be left is the carbonic acid. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Acids lower the pH of a solution, so the pH of blood would drop.
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the definition of a buffer to determine what would happen if the base was removed. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize that bicarbonate was the base in the problem? One clue was that carbonic acid had to be the acid, based on its name. Did you recall that acids lower the pH and bases raise the pH? 68) B 69) A 70) C
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Clarify Question • What is the key concept addressed by the question? The question asks about the formation of covalent bonds. • What type of thinking is required? You are being asked to apply your knowledge of the structure of atoms to predict how many covalent bonds carbon dioxide could form. • What key words does the question contain and what do they mean? o Valence electrons: electrons in the outer shell of an atom. Gather Content • What do you know about covalent bonds? How does it relate to the question? o Typically an atom is most stable if it has a full outer shell. This can be accomplished by gaining, losing, or sharing electrons. When two electrons are shared between two atoms this forms a covalent bond. Consider Possibilities • What other information is related to the question? Which information is most useful? o The name carbon dioxide indicates that there are one carbon atom and two oxygen atoms in this molecule. o Carbon has 4 valence electrons, so it needs to share 4 more electrons to get a full outer shell. This means it can form 4 covalent bonds. o Oxygen has 6 valence electrons, so it needs to share 2 more electrons to get a full outer shell. This means each oxygen atom can form 2 covalent bonds Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The carbon atom can form a double bond with each of the oxygen atoms. That will give the carbon atom 4 bonds and each oxygen atom 2 bonds needed to fill their outer shells. The structure O=C=O would thus contain two double covalent bonds. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the structure of an atom to predict how many bonds would form in carbon dioxide. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you have trouble figuring out how many bonds carbon and oxygen each needed to form to be stable? Were you confused on whether all of the bonds were between C and O or did you try to make some O-O bonds? 71) A 72) B
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Clarify Question • What is the key concept addressed by the question? The question asks about nonpolar amino acids. • What type of thinking is required? You are being asked to apply your knowledge of polarity to predict how this would affect the structure of a protein. • What key words does the question contain and what do they mean? o Polar: molecules in which electrons are not shared equally between atoms, leading to partial charges on the atoms. o Nonpolar: molecules in which electrons are shared equally between atoms, leading to no partial charges. Gather Content • What do you know about nonpolar molecules? How does it relate to the question? o Nonpolar molecules do not interact well with water, which is a polar molecule. These nonpolar molecules actually interfere with the formation of hydrogen bonds between water molecules. Consider Possibilities • What other information is related to the question? Which information is most useful? o The inside of an animal cell contains cytoplasm which is made up of a lot of water. Thus the inside of the cell is a polar environment. o Nonpolar amino acids in the inside of a cell do not interact well with and are repelled by the water of the cytoplasm.
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The repulsion of nonpolar amino acids by water will cause them to cluster in the center of the protein where they are shielded from water. This is why most proteins are ball shaped, with the nonpolar or hydrophobic amino acids in the center of the ball. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply polar and nonpolar definitions to predict the structure of a protein. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you understand the difference between polar and nonpolar amino acids? Did you realize that the inside of the cell would be a polar environment? Did you know that nonpolar groups will cluster near each other to be shielded from water? 73) A
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Clarify Question • What is the key concept addressed by the question? The question asks about the ability of water to absorb heat. • What type of thinking is required? You are being asked to apply your understanding of the properties of water to explain the effect of adding antifreeze. • What key words does the question contain and what do they mean? o Cooling efficiency: a measure of how well a solution can absorb heat. Gather Content • What do you know about the properties of water? How does it relate to the question? o Water has a very high heat capacity. This means that it can absorb a lot of heat. Consider Possibilities • What other information is related to the question? Which information is most useful? o Adding ethylene glycol decreases the cooling efficiency of water in the radiator. This is done to lower the freezing point of water, which keeps the radiator from freezing solid in the winter. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The ethylene glycol has a lower heat capacity than water, so adding ethylene glycol to the radiator decreases the amount of heat that the Version 1
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water can absorb. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the properties of water to explain the ability of water to absorb heat. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize that the property of water relevant to cooling efficiency was its heat capacity? Did you recognize that the question was not asking about changes in the freezing point? 74) C
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Clarify Question • What is the key concept addressed by the question? The question asks about forming covalent bonds. • What type of thinking is required? You are being asked to apply your knowledge of the structure of an atom to predict how many bonds it can form. • What key words does the question contain and what do they mean? o Saturated fat: molecules with a backbone of C-C bonds, with as many C-H bonds as possible. Gather Content • What do you know about covalent bonds? How does it relate to the question? o Carbon has 4 valence electrons, and needs to share an additional 4 electrons to have a full outer shell. This means it needs to form 4 covalent bonds. Consider Possibilities • What other information is related to the question? Which information is most useful? o In a saturated fat there is a backbone of C atoms attached by covalent bonds giving a structure like: -C-C-Co These covalent bonds provide 2 additional electrons, leaving a need for 2 more for carbon to have a full outer shell. Choose Answer • Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer? o To obtain the remaining 2 electrons, each C atom forms covalent bonds with two H atoms. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the structure of an atom to predict how many bonds would form in a saturated fat. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you understand what was meant by a saturated fat? Could you figure out how many total covalent bonds each C atom would form?
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Chapter 03 13e MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 1) Organic molecules have a carbon backbone and_________blank such as -OH and -NH2 that affect their chemical properties. A) R groups B) extensiongroups C) functionalgroups D) chemical groups
2) A polysaccharide that is composed of modified glucose subunits and is found in the exoskeletons of insects and crustaceans is known as: A) chitin B) starch C) amylose D) glycogen
3)
These biological compounds are nonpolar and insoluble in water: A) carbohydrates B) lipids C) proteins D) nucleic acids
4)
A DNA molecule containing 32% thymine would contain how much cytosine? A) 18% B) 32% C) 36% D) 64%
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5) The covalent bonds connecting monomer units in sugars can be formed by the removal of a water molecule. This reaction is referred to as: A) a hydrolysisreaction. B) anoxidation-reduction reaction. C) a dehydrationreaction. D) a hydration reaction.
6) This atom in its unbound state has four valence electrons. These electrons readily form single, double, and even triple bonds among themselves to become stable. This atom is: A) carbon. B) hydrogen. C) oxygen. D) nitrogen. E) phosphorus.
7)
Macromolecules are broken down to monomers in_________blank A) anabolicreactions. B) hydrolysisreactions. C) denaturationreactions. D) dehydrationreactions.
8) Relatively small organic molecules with a central carbon atom bonded to a carboxyl group, an amino group, a carbon containing group, and a hydrogen atom are called: A) amino acids. B) fatty acids. C) enzymes. D) peptides. E) nucleotides.
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9)
Macromolecules that are used by all organisms to store hereditary information are called: A) transfer RNAmolecules. B) messenger RNA molecules. C) proteins. D) ribosomalRNA molecules. E) DNA molecules.
10)
DNA and RNA contain functional units known as: A) peptides. B) enzymes. C) amino acids. D) nucleotides. E) fatty acids.
11)
Carbohydrates are polymers formed from structural units called: A) amino acids. B) fatty acids. C) nucleotides. D) glycerols. E) monosaccharides.
12)
Proteins are polymers formed of structural units called: A) fatty acids. B) amino acids. C) nucleotides. D) phosphate groups. E) monosaccharides.
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13)
Lipids are the only class of macromolecules that contain: A) amino acids. B) nucleotides. C) fatty acids. D) phosphate groups. E) monosaccharides.
14) A double stranded DNA strand contains 26 pyrimidines. How many purines will the copied strand contain? A) 0 B) 13 C) 26 D) 52
15) A monosaccharide that plays an important role in energy storage is a six-carbon sugar called: A) galactose. B) lactose. C) cellulose. D) glucose. E) sucrose.
16)
Humans are unable to derive metabolic energy from cellulose because: A) cellulose contains very little chemical energy. B) cellulose is not part of a normal diet. C) cellulose digestingenzymes are absent from the human gut. D) cellulose does not taste good. E) cellulose is present in large quantities in the gut.
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17)
What polysaccharide forms the long, tough fibers found in plant cell walls? A) cellulose B) starch C) glycogen D) chitin E) amylopectin
18)
The biological macromolecule that is least soluble in water is a(n): A) protein. B) nucleic acid. C) enzyme D) lipid. E) carbohydrate.
19)
Common lipids for energy storage are: A) phospholipids. B) steroids. C) triglycerides. D) cholesterols. E) waxes.
20)
Three fatty acids bonded together with a glycerol are found in a(n): A) alcohol. B) enzyme. C) phospholipid. D) chlorophyll pigment. E) triglyceride.
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21)
Biological membranes contain bilayers containing mostly_________blank. A) phospholipids B) oils C) prostaglandins D) triglycerides E) cholesterol
22) This type of lipid is found in pigments such as chlorophyll, in the visual pigment retinal, and in rubber: A) phospholipid. B) terpene. C) steroid. D) prostaglandin. E) wax.
23)
Amino acids are linked together by peptide bonds in a_________blank A) phospholipid. B) nucleic acid. C) polysaccharide. D) polypeptide. E) starch.
24)
The specific amino acid sequence of a protein is its_________blank. A) primarystructure B) secondarystructure C) tertiarystructure D) quaternarystructure
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25)
What is the difference in the bonding between alpha-helix and beta sheet?
A) Hydrogen bondingbetween the amides only occurs in one of these two types of secondarystructures. B) Hydrogen bondingoccurs between the amides of adjacent chains in the sheets instead ofbetween the amides in different parts of the helices. C) Sulfur bridges allow the spring like turns in alpha helices and van der Waals dispersion allows the folds in beta sheets. D) Hydrogen bonding always occurs in the alpha helices but only occurs inparallel beta sheets.
26) Denaturation disrupts the secondary and tertiary structure of proteins. However, denaturation is not strong enough to disrupt what interaction that is relevant to protein structure? A) hydrogen bonds B) ionic bonds C) van der Waalsattraction D) hydrophobicexclusion E) peptide bonds
27)
The information storage molecules of cells are called: A) proteins. B) phospholipids. C) enzymes. D) hormones. E) nucleic acids.
28)
The nitrogenous base that is only found in DNA and not in RNA is:
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A) adenine. B) cytosine. C) guanine. D) thymine. E) uracil.
29)
The nitrogenous base that is only found in RNA and not DNA is: A) adenine B) cytosine C) guanine D) thymine E) uracil
30) Fructose and galactose both have six carbon atoms, twelve hydrogen atoms and six oxygen atoms; just like glucose. A friend of yours says: "Since those sugars have the same number of atoms, they should have the same name." You answer: "While they do have the same number and type of atoms, A) they are all polysaccharides and have slightly different functions within organisms and therefore have different names." B) they are named differently because of their quaternary structures, which is very important in carbohydrates, especially glucose." C) they are named differently because when heated above their optimal temperature they become denatured and will not react with their substrates." D) they are named differently because they are involved in different DNA nucleotide formation." E) they are named differently because they are alternate forms of the monosaccharide, glucose."
31) A candy bar contains 108 calories per serving. There are 4 grams of carbohydrate, 5 grams of protein, and 8 grams of fat in a serving. How many of the calories come from fat? Note: One food calorie equals one kilocalorie.
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A) 20 B) 16 C) 72 D) 18
32)
A nucleic acid contains uracil, allowing you to conclude that: A) this nucleic acidis DNA. B) this nucleic acidis RNA. C) this nucleic acidcould be either DNA or RNA.
33)
A nucleic acid contains thymine, allowing you to conclude that: A) this nucleic acidis DNA. B) this nucleic acidis RNA. C) this nucleic acidcould be either DNA or RNA.
34)
Proteins are created with: A) phosphodiesterbonds. B) peptide bonds. C) triglycerides. D) polysaccharides.
35)
Phospholipids are made up of: A) a glycerol andthree fatty acids. B) four fused carbonrings. C) a phosphate, twofatty acids and a glycerol. D) five-carbon rings with two nonpolar tails.
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36)
Cellulose is composed of monomers of: A) ribose B) deoxyribose C) α-glucose D) β-glucose
37)
Enzymes function to: A) react with otherenzymes to form a product. B) catalyze chemicalreactions. C) transportmolecules and ions across membranes. D) regulate messagesbetween cells.
38)
The types of bonds found in nucleic acids are: A) phosphodiesterbonds. B) peptide bonds. C) ionic bonds. D) nonpolar covalent bonds.
39)
Which of the following reactions is a dehydration reaction? A) A + H2O → B + C B) A + B → C + H2O C) A + B + H2O → C D) A → B + C+ H2O
40)
Which of the following reactions is a hydrolysis reaction?
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A) A + H2O → B + C B) A + B → C + H2O C) A + B + H2O → C D) A → B + C+ H2O
41)
The DNA sequence capable of pairing with 5' CGATTAGT 3' is: A) 3' GCTAATCA 5'. B) 3' CGATTAGT 5'. C) 5' GCTAATCA 3'. D) 5' CGATTAGT 3'.
42) You recently identified a novel protein that contains several membrane-spanning domains. You would predict that the amino acids embedded in the membrane would have_________blank side groups. A) nonpolar B) polaruncharged C) positivelycharged D) negativelycharged
43) L-lysine is an essential amino acid and must be supplied in the diet. By comparison, the stereoisomer D-lysine is not biologically active. Why can your body only utilize one form? A) Since the L form and D form are enantiomers, they will bind together and inhibit utilization of the D form. B) Since the L form and D form are chiral molecules, they will bind together and inhibit utilization of the D form. C) Antibodies recognize the D form and destroy it before your body can use it for nutritional purposes. D) Enzymes can only recognize a single, specific stereoisomer.
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44) People who are lactose intolerant can often consume some products made from milk such as cheese and yogurt because microorganisms in their digestive system consume the lactose. By comparison, people with a true milk allergy, which involves an immune response to milk protein, cannot consume milk or products made from milk. Given this information, what can you conclude about milk? A) The protein that causes a true milk allergy is lactose. B) All people who are lactose intolerant are also allergic to milk. C) Yogurt contains live and active cultures of Lactobacillus acidophilus bacteria and therefore prevents an allergic response in people with a true milk allergy. D) Lactose is a carbohydrate, not a protein, and is therefore not the cause of true milk allergies.
45) Egg whites consist primarily of water and the protein albumin. When you fry an egg, why does the egg white turn from clear to white? A) The protein becomes dissociated. B) The protein acquires tertiary structure. C) The protein becomes denatured. D) The protein becomes dehydrated.
46) Margarine is made by hydrogenating vegetable oils so that they take on the consistency of butter. Propose a chemical basis for this change from a liquid to a solid. A) Hydrogenation of fats changes them from unsaturated to saturated, which makes them more solid. B) Hydrogenation of fats changes them from saturated to unsaturated, which makes them more solid. C) Trans-fatty acids are changed from unsaturated to saturated, allowing them to solidify. D) Trans fatty acids are changed from saturated to unsaturated, allowing them to solidify.
47) Vitamin D can be synthesized by the body from a derivative of cholesterol. Given this information, predict vitamin D's solubility.
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A) Vitamin Dis water-soluble. B) Vitamin D is fat-soluble. C) Vitamin D is soluble in both water and fat. D) Vitamin D is not soluble in either water or fat.
48) You arrive late to a biological seminar. However, just as you enter the room, you hear the speaker referring to the "amino end" and the "carboxyl end" of a macromolecule. Immediately, you know that they are talking about a: A) carbohydrate. B) protein. C) nucleic acid. D) lipid.
49) You arrive late to a biological seminar. However, just as you enter the room, you hear the speaker referring to the "five-prime end" and the "three-prime end" of a macromolecule. Immediately, you know that they are talking about a: A) carbohydrate. B) protein. C) nucleic acid. D) lipid.
50)
What type of monomer does ATP represent? A) monosaccharide B) amino acid C) nucleotide D) fatty acid E) glycerol
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51) The digestive enzyme pepsin works in the acidic environment of the stomach to hydrolyze peptide bonds. As a result, pepsin affects which macromolecule? A) carbohydrate B) protein C) DNA D) lipid
52) The human immunodeficiency virus (HIV) uses RNA, rather than DNA, to encode genetic information. During infection, however, HIV uses an enzyme known as reverse transcriptase to generate double-stranded DNA. Generally speaking, how would the enzyme generate a double strand of DNA from a single strand of RNA? A) Reverse transcriptase first catalyzes the synthesis of a DNA copy from the viral RNA, and then catalyzes the synthesis of a second strand of DNA complementary to the first one. B) Reversetranscriptase first catalyzes the synthesis of a RNA copy from the viral DNA,and then catalyzes the synthesis of a second strand of DNA complementary to thefirst one. C) Reversetranscriptase first catalyzes the synthesis of a DNA copy from the viral RNA,and then catalyzes the synthesis of a second strand of DNA from the viralRNA.
53) You have recently identified a novel protein and obtained its sequence. How could you use this sequence to predict the function of the protein? A) By determiningthe secondary structure of the protein. B) By using the sequence to makeantibodies against the protein. C) By looking forconserved domains. D) By determiningthe DNA sequence that could encode the protein.
54) At the pH of most bodily fluids, which functional group will lose a proton and which functional group will accept a proton?
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A) sulfhydryl;carbonyl B) Hydroxyl; amino C) amino;carboxyl D) carboxyl;amino E) carbonyl; Hydroxyl
55) A bobcat is feeding on a white-tailed deer. It first eats the liver, which is rich in stored sugars. In what form would sugar be stored in the deer’s liver? A) Glucose B) Maltose C) Glycogen D) Amylose E) Cellulose
56) Seth ordered lobster at a restaurant and realized that the outer shell was made of a tough carbohydrate similar to that used to make the carapace of a cockroach. What do you think the outer shell of the lobster is made of? A) Fibrin B) Cellulose C) Glycogen D) Chitin E) Amylopectin
57) Yogurt contains galactose and glucose, which are generated when bacterial enzymes act on milk sugars. What is the main source of the galactose in yogurt? A) Maltose B) Sucrose C) Lactose D) Fructose E) Glycogen
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58) Hemoglobin transports oxygen in the blood and consists of a chain of 146 amino acids. How many different types of amino acids are used to construct proteins? A) 2 B) 20 C) 146 D) 200
59) Luke sprained his ankle, tearing some of the collagen protein that forms his ligaments. Some types of collagen consist of three polypeptide chains twisted together to form a rope-like strand. What level of protein structure does this rope-like strand represent? A) Primary B) Secondary C) Tertiary D) Quaternary
60)
Which amino acid is least soluble in water? A) Isoleucine B) Alanine C) Glutamine D) Glycine
61)
Which amino acid is most soluble in water? A) Serine B) Valine C) Glycine D) Leucine
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62) The formula for glucose is C6H12O6. What is the formula for a polymer made by linking ten glucose molecules together by dehydration synthesis?
A) C60H120O60 B) C60H102O51 C) C60H100O50 D) C60H111O51
63) The myoglobin protein, which carries oxygen in muscle cells, has only the first three levels of protein structure. What can you infer about myoglobin? A) Myoglobin lacks hydrogen bonds B) Myoglobin is made of nucleic acids C) Myoglobin is not helical or pleated D) Myoglobin is madeof only one polypeptide chain
64)
A phosphorus shortage in soil would make it difficult for plants to produce: A) cellulose B) amylose C) starch D) DNA
65)
This nucleotide containing molecule is commonly used to carry electrons in the cell. A) ADP B) ATP C) NAD+ D) pyruvic acid
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66) Benedict's reagent is a chemical that is used to test for the presence of a free aldehyde functional group on glucose. The aldehyde is used when glucose and fructose bind together to form sucrose, so the Benedict's test will be negative. Starch contains a great deal of glucose but gives a negative Benedict's test because: A) all of thealdehyde groups on the starch are oxidized and cannot react with the Benedict'sreagent. B) starch is not soluble in water and cannot react with Benedict's reagent. C) glucose in starchhas lost a carbon atom and cannot react with Benedict's reagent. D) only the glucoseat the end of a chain of starch will have an exposed aldehyde functionalgroup to react with Benedict's reagent.
67) What characteristic would the R groups of amino acids have if they are located within the interior of biological membranes? A) The R groups wouldbe hydrophilic. B) The R groups wouldhydrophobic. C) The R groups wouldbe polar. D) The R groups wouldbe able to form ionic bonds.
68) Sudan IV, a dye that binds to nonpolar molecules, is used to detect the presence of macromolecules in food. Sudan IV would test positive in the presence of what macromolecule? A) Starch B) DNA C) Chitin D) Hemoglobin E) Fats
69) How many water molecules are produced during the formation of a triglyceride from fatty acids and glycerol?
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A) 0 B) 1 C) 2 D) 3 E) 4
70) Acyclovir is an antiviral chemical that resembles a nucleotide but lacks a 3' OH group and cannot form phosphodiester bonds. Why is Acyclovir useful in treating some viral infections? A) Acyclovir stopsviral protein synthesis. B) Acyclovir haltsviral DNA replication. C) Acyclovir blocksthe assembly of viral cell capsules. D) Acyclovirhydrolyzes viral polysaccharides.
71) α-glucose is present in potatoes and β-glucose is present in wood. Both are glucose molecules but one can be used by humans to synthesize ATP and one cannot. Based on this information, what is the best explanation on why humans can only digest one of the glucose types? A) α-glucose is C6H12O6 and β-glucose is C5H12O6. B) α-glucose and β-glucose are stereoisomers with OH groups oriented differently. C) Only α-glucose can form polysaccharides. D) α-glucose is a chain and β-glucose is a ring.
72) You label cells with a radioactive isotope of sulfur (35S). The only molecules that would be radioactively labeled in these cells are:
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A) Lipids B) Proteins C) Carbohydrates D) Nucleic acids
73)
A polymer with the sequence 5' ACGTACGAATAG 3' is a: A) protein. B) piece of RNA. C) piece of DNA. D) polysaccharide.
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Answer Key Test name: Chap 03_13e_Raven 1) C 2) A 3) B 4) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about base pairing in DNA. • What type of thinking is required? o You are being asked to analyze the percentage of thymine in a DNA molecule and calculate the amount of cytosine. • What key words does the question contain and what do they mean? o 32% thymine: this means that 32% of the total nucleotides in the DNA molecule are thymine (T) Gather Content • What do you know about base pairing? How does it relate to the question? o DNA is double stranded and between the strands a thymine pairs with adenine and cytosine pairs with guanine through hydrogen bonds. Consider Possibilities • What other information is related to the question? Which information is most useful? o If 32% of the bases are thymine then there will be an equal amount of adenine (32%). The sum of thymine and adenine is 64%. o The rest of the nucleotides must be cytosine and guanine, so 100% 64% = 36% Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If cytosine and guanine add up to 36% of the total nucleotides, and Version 1
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there are equal amounts of both nucleotides, then cytosine and guanine each comprise 18% of the total nucleotides in the DNA molecule. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze the composition of a DNA molecule to predict the amount of cytosine. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that thymine and adenine pair and will be present in equal amounts? Did you recall that cytosine and guanine also pair and will be present in equal amounts, accounting for the remaining percentage of nucleotides? Did you realize that the total percentage of nucleotides add up to 100%? 5) C 6) A 7) B 8) A 9) E 10) D 11) E 12) B 13) C 14) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about base pairing between pyrimidines and purines. • What type of thinking is required? o You are being asked to apply your knowledge of how pyrimidines and purines bind to each other in forming a double strand of DNA. • What key words does the question contain and what do they mean? o Pyrimidines: the nucleotides cytosine and thymine. o Purines: the nucleotides adenine and guanine. Gather Content • What do you know about base pairing? How does it relate to the question? o Pyrimidines and purines hydrogen bond on complementary strands of DNA. Thymine pairs with adenine and cytosine pairs with guanine. Consider Possibilities • What other information is related to the question? Which information is most useful? o Because pyrimidines and purines form base pairs, for each pyrimidine there will be a purine. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If there are 26 pyrimidines in a double strand of DNA, then there will be 26 purines. Version 1
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to consider the structure of DNA to predict the number of purines from the number of pyrimidines. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall what pyrimidines and purines are? Did you realize that the two form base pairs in DNA? 15) D 16) C 17) A 18) D 19) C 20) E 21) A 22) B 23) D 24) A 25) B 26) E 27) E 28) D 29) E 30) E 31) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about calculating calories in fat. • What type of thinking is required? o You are being asked to apply the number of calories per gram of fat to calculate the fat calories in a candy bar. • What key words does the question contain and what do they mean? o 8 grams of fat: to calculate how many of the calories come from fat, you need to know how much fat is in the candy bar. Gather Content • What do you know about calories per gram? How does it relate to the question? o Fats contain 9 calories/gram and contain more calories than carbohydrates or proteins because fats are more reduced. o Carbohydrates and proteins contain only 4 calories/gram because they are partially oxidized. Consider Possibilities • What other information is related to the question? Which information is most useful? o 8 grams of fat – the other numbers are not necessary to solve the problem. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o 8 grams of fat x 9 calories/gram = 72 calories. Version 1
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the calories per gram of fat to calculate the number of calories from fat in a candy bar. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that fat contains 9 calories per gram? Did you realize that only the number of grams of fat were needed for the calculation? 32) B 33) A 34) B 35) C 36) D 37) B 38) A 39) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about dehydration reactions. • What type of thinking is required? o You are being asked to apply your knowledge of dehydration reactions to identify one. • What key words does the question contain and what do they mean? o Dehydration reaction: reactions used to link two monomers together, releasing water in the process. Gather Content • What do you know about dehydration reactions? How does it relate to the question? o Dehydration reactions are used to join two monomers together. o Water is released in the reaction. Consider Possibilities • What other information is related to the question? Which information is most useful? o The two reactions with water on the reactant side of the reaction (left side) are using water and are thus not dehydration reactions. A + B + H2O → C and A + H2O → B + C o Reactions with one reactant and two products are breaking down a compound and not synthesizing molecules. A + H2O → B + C and A → B + C+ H2O Choose Answer • Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer? o The best answer is A + B → C + H2O. In this case the two reactants A and B are being joined together to form the product C. Water is generated as a byproduct in the reaction making it a dehydration. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the definition of a dehydration reaction to identify it from several examples. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall the definition of a dehydration reaction and that water was a product? Did you realize that in addition to producing water these involve synthesizing a polymer from two monomers? 40) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about hydrolysis reactions. • What type of thinking is required? o You are being asked to apply your knowledge of hydrolysis reactions to identify one. • What key words does the question contain and what do they mean? o Hydrolysis reaction: reaction that uses water to break down a polymer into monomers. Gather Content • What do you know about hydrolysis reactions? How does it relate to the question? o Hydrolysis reactions are used to break a polymer down into monomers. The roots “hydro” meaning water and “lysis” meaning 'to break' give clues to what this reaction is doing. o Water is used in the reaction. Consider Possibilities • What other information is related to the question? Which information is most useful? o The two reactions with water on the product side of the reaction (right side) are releasing water and are thus not hydrolysis reactions: A → B + C+ H2O and A + B → C + H2O o Reactions with one product and two reactants are synthesizing molecules and are not breaking them down: A + B → C + H2O and A + B + H2O → C Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The best answer is A + H2O → B + C. In this case the reactant A is being broken down to form B and C. Water is used in the reaction to break down A, making it a hydrolysis reaction. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the definition of a hydrolysis reaction to identify it from several examples. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall the definition of a hydrolysis reaction and that water is used to lyse or break down a molecule? Did you realize that in addition to using water these reactions involve breaking down a polymer into two monomers? 41) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about base pairing in DNA. • What type of thinking is required? o You are being asked to apply your knowledge of base pairing in DNA to pick the complementary strand for a DNA sequence. • What key words does the question contain and what do they mean? o 5' CGATTAGT 3' : 5’ and 3’ indicate the orientation of the strand of DNA, and each letter represents an abbreviated nucleotide base. Gather Content • What do you know about base pairing? How does it relate to the question? o The two strands of DNA will pair with each other in a reverse orientation, so if one strand is in the 5’ →3’ orientation, the other will be 3’ ← 5’. o On each strand guanine (G) will pair with cytosine (C) and adenine (A) will pair with thymine (T). Consider Possibilities • What other information is related to the question? Which information is most useful? o The strand in the question is in the orientation 5’ →3’, so the complementary strand will be 3’ ← 5’. o The strand in the question has the sequence CGATTAGT so the complementary sequence will be GCTAATCA Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Putting these two requirements together, the correct answer is 3' GCTAATCA 5'. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge of the structure of DNA to predict the complementary sequence of a given strand. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that DNA binds in a reverse complementary orientation? Did you remember that G pairs with C and A with T? 42) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about membrane spanning domains of a protein. • What type of thinking is required? o You are being asked to apply your knowledge of membrane-spanning domains to predict the properties of amino acids in these domains. • What key words does the question contain and what do they mean? o Membrane: a lipid bilayer that has polar head groups interacting with water and long nonpolar fatty tails that point into the membrane and away from water. o Membrane-spanning domains: segments of a protein that cross a lipid bilayer. Gather Content • What do you know about amino acid side groups? How does it relate to the question? o There are 20 common amino acids, each with unique side groups (functional groups). Some are charged or polar, allowing them to interact with water. Other side groups are nonpolar and hydrophobic and will be repelled by water. Consider Possibilities • What other information is related to the question? Which information is most useful? o The center of a membrane contains a nonpolar (hydrophobic) environment. In order for a protein to cross a membrane, the side chains would need to be soluble in this lipid environment. Charged and polar side groups will be soluble in water and would not be soluble in a membrane. Version 1
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Nonpolar side chains on a protein would be most soluble in a membrane. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the properties of a membrane to predict which amino acid side chains would be found in a membranespanning domain. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you understand that a membrane would contain a nonpolar and hydrophobic environment? Did you recall that polar and charged amino acid side chains are hydrophilic and would not dissolve well in hydrophobic membranes? 43) D 44) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about different disorders related to the consumption of milk. • What type of thinking is required? o You are being asked to analyze symptoms of two different disorders to determine the role of lactose and proteins in each. • What key words does the question contain and what do they mean? o Lactose intolerant: when individuals cannot break down lactose and if they consume milk, bacteria in their guts break down the lactose producing gas and bloating. o Milk allergy: when the proteins in milk trigger an allergic reaction. Gather Content • What do you know about milk proteins and lactose? How does it relate to the question? o Lactose is a disaccharide that is broken down into glucose and galactose by the enzyme lactase. People who lack this enzyme cannot break down lactose and are considered lactose intolerant. When milk is made into cheese or yogurt, microorganisms chew up the lactose, so people who are lactose intolerant can often eat these foods. o Milk proteins are digested by enzymes in the stomach, but fragments can trigger an immune response in some individuals. These milk proteins are not degraded when making cheese or yogurt, so people with milk allergies cannot eat these foods. Consider Possibilities • What other information is related to the question? Which information is most useful? Version 1
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o Lactose is a sugar and not a protein, so it does not trigger an allergic response. o Lactose intolerance and milk allergies are different disorders with separate causes. o Milk allergies are to milk proteins, and people with these allergies cannot eat cheese or yogurt made by active cultures of bacteria. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The best answer is that lactose is a carbohydrate and while it contributes to lactose intolerance, it is not a cause of allergies. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze the description of lactose intolerance and milk allergies to explain the role of carbohydrates and proteins in each. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize that lactose is a carbohydrate and not likely to cause allergies? Did you realize that lactose intolerance and milk allergies were separate disorders? 45) C 46) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about the effect of hydrogenating oil. • What type of thinking is required? o You are being asked to apply your knowledge of the effects of fat hydrogenation on consistency. • What key words does the question contain and what do they mean? o Hydrogenating vegetable oil: adding more hydrogens to an unsaturated fat to make it more saturated. This can also lead to the formation of trans fats. o Trans-fatty acids: the product formed when unsaturated fatty acids are hydrogenated. Gather Content • What do you know about the effect of saturation on the consistency of a fat? How does it relate to the question? o Saturated fats do not have C=C double bonds, so their fatty acid tails can compact together tightly. This makes them more likely to be a solid at room temperature. Butter is a good example of a saturated fat. If heat is added the butter can melt from a solid to a liquid. o Unsaturated fats do have C=C double bonds, that introduce kinks or bends into the fatty acid tails. This prevents the fats from getting as close to each other, which makes them more likely to be a liquid at room temperature. Corn oil is a good example of this; if the oil is put in a freezer it will eventually form a solid. Consider Possibilities • What other information is related to the question? Which information is most useful? Version 1
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o Adding hydrogens to an unsaturated fat will reduce bends and make it more solid. These hydrogenated unsaturated fats are often trans-fats. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The correct answer is that hydrogenation of fats changes them from unsaturated to saturated, which is more solid. Trans-fatty acid answers are not correct because these are the products of hydrogenation. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to consider the structure of a fat to predict its melting temperature. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall what was meant by unsaturated fat, saturated fat, and trans-fat? Did you understand the impact of saturation on how solid a fat would be? Did you recall that trans-fats and saturated fats are made by hydrogenating unsaturated fats? 47) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the solubility of vitamin D. • What type of thinking is required? o You are being asked to apply the solubility of cholesterol to vitamin D made from cholesterol. • What key words does the question contain and what do they mean? o Derivative of cholesterol: cholesterol was the reactant in a reaction and vitamin D was the product made from the cholesterol. Gather Content • What do you know about the solubility of cholesterol? How does it relate to the question? o Cholesterol is a lipid and it is fat-soluble. Lipids are hydrophobic, nonpolar molecules that do not dissolve well in water. Consider Possibilities • What other information is related to the question? Which information is most useful? o Because vitamin D is made from cholesterol, it should have similar solubility. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Vitamin D is fat-soluble because it is a lipid molecule like cholesterol. Reflect on Process Version 1
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to consider the structure of vitamin D to predict its solubility. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that cholesterol is a lipid and thus fat-soluble and not water-soluble? Did you realize that if vitamin D was made from cholesterol it would have similar solubility? 48) B 49) C 50) C 51) B 52) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about reverse transcription. • What type of thinking is required? o You are being asked to apply your knowledge of transcription to predict the mechanism of reverse transcription. • What key words does the question contain and what do they mean? o Single strand of RNA: an intermediate in the central dogma, made in cells from ribonucleotides. o Double strand of DNA: the primary information storage molecule containing two antiparallel strands of deoxyribonucleotides. o Reverse transcriptase: an enzyme that converts RNA into DNA. Gather Content • What do you know about transcription? How does it relate to the question? o Any time a nucleic acid is synthesized, new nucleotide bases are added one at a time by inserting a base complementary to the template strand. o In transcription, a double stranded DNA is used as a template to create a single stranded RNA. Consider Possibilities • What other information is related to the question? Which information is most useful? o In reverse transcription a single stranded RNA is used as a template to make DNA. The DNA will have a complementary sequence to the RNA, so only one of the two strands of DNA can be made from the RNA as a template. Version 1
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Both DNA and RNA are made one strand at a time. So to make two strands of DNA two rounds of synthesis will be performed. In the first the viral RNA will serve as a template to make a copy of DNA that is complementary to the RNA. Next, the newly made DNA will serve as a template to make a second strand of DNA, generating a double stranded DNA. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge of transcription to predict the mechanism of reverse transcription. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember what the reactants and products of transcription were? Could you then use this to determine the reactants and products of reverse transcription? Did you think that the viral RNA could serve as a template to both strands of DNA? 53) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about domains of a protein. • What type of thinking is required? o You are being asked to apply your knowledge of domains to explain that they determine the function of a protein. • What key words does the question contain and what do they mean? o Protein sequence: the primary structure of a protein, listing the amino acids in order. o Function: refers to specific activities of a protein. Gather Content • What do you know about protein function? How does it relate to the question? o The function of a protein is determined by its tertiary or three dimensional structure. Consider Possibilities • What other information is related to the question? Which information is most useful? o The primary structure or amino acid sequence contains information that allows proteins to fold into specific secondary structures (alpha helix or beta sheet). This information is typically obtained by determining the DNA sequence of the gene encoding the protein and then translating it on the computer. o The secondary structure of a protein is important in determining the final tertiary structure of a protein, but does not always have specific answers.
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The tertiary structure, or three-dimensional shape, of a protein determines its function. This structure can be broken into smaller conserved domains that fold into three-dimensional structures with distinct activities. By looking for these conserved domains in a sequence you can make predictions about the function of the complete protein. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge of the different levels of protein structure to explain which would determine the function of a protein. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you understand that the DNA sequence would give you the same sequence you already had? Did you think that the secondary structure of a protein determined the function of a protein? Did you realize that domains are three-dimensional structures that have specific functions? 54) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about functional groups that are acids and bases. • What type of thinking is required? o You are being asked to apply your knowledge of functional groups that are acids and bases to predict which would gain or lose a proton at a neutral pH. • What key words does the question contain and what do they mean? o Functional group: a chemical group with specific properties. o Proton: an H+ ion that is lost by acids and gained by bases at neutral pH. Gather Content • What do you know about functional groups? How does it relate to the question? o Functional groups have specific activities based on their chemical structure. They can be polar or nonpolar, some can behave as acids or bases. Consider Possibilities • What other information is related to the question? Which information is most useful? o Sulfhydryl groups are –SH, these are polar but don’t readily behave as acids. o Hydroxyl groups are –OH, these are polar but don’t behave as acids. o Carbonyl groups are –CH=O and do not behave as acids. Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Carboxyl groups are –CO2H and the proton (H+) can be lost as an acid forming –CO2-. o Amino groups are –NH2 and can gain a proton as a base forming – NH3+. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to consider the structure of functional groups to predict if they will form an acid or base. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember the structures of each of the functional groups? Did you know which would behave as an acid or a base? 55) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about how sugars are stored in an organ in animals. • What type of thinking is required? o You are being asked to apply your knowledge of the storage of sugars in animals to a specific example. • What key words does the question contain and what do they mean? o Deer liver: an organ from an animal. o Stored sugars: complex sugars stored for long term use as opposed to simple sugars in the blood stream for immediate use. Gather Content • What do you know about stored sugars in animals? How does it relate to the question? o For long term storage of sugars, plants and animals use complex carbohydrates. These complex carbohydrates contain multiple glucose molecules stuck together with α1-4 linkages. In animals this is called glycogen while in plants it is amylose or starch. Consider Possibilities • What other information is related to the question? Which information is most useful? o For short term use, monosaccharides and disaccharides are used more often. Examples include glucose and maltose. o Some structural complex carbohydrates are made up of β1-4 linkages. The most common example is cellulose in plants. Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The correct answer is glycogen. Liver glycogen is used to keep blood glucose levels constant. If blood glucose becomes low, liver glycogen is broken down, releasing glucose into the blood. If blood glucose rises, some is taken up by the liver and converted into glycogen. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the definitions of different carbohydrates to explain which would be found in the liver of a deer. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall which forms of carbohydrate would be found in animals? Did you recall which would be used for long term energy storage? 56) D 57) C 58) B 59) D 60) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about the solubility of functional groups in water. • What type of thinking is required? o You are being asked to apply your knowledge of functional groups to predict which would be least soluble in water. • What key words does the question contain and what do they mean? o Least soluble in water: the amino acid does not dissolve well in water. Gather Content • What do you know about solubility in water? How does it relate to the question? o The more polar a molecule is, the better it can dissolve in water. The more nonpolar functional groups a molecule has, the less soluble it will be in water. Consider Possibilities • What other information is related to the question? Which information is most useful? o All four of the amino acids will have the same backbone structure with an amino group, an α-carbon, and a carboxyl group. The differences will be with the structure of the side chains. o Glutamine is a polar, charged amino acid and will be the most soluble amino acid. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o Among the remaining three amino acids, each has the following side chains: glycine (H), alanine (CH3), and isoleucine (C4H9). While none of these have polar groups, isoleucine has the most carbons and will be the most nonpolar and hydrophobic. This will make isoleucine the least soluble in water. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to consider the structure of an amino acid to predict its solubility. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you know the structures of the amino acid side chains? Did you know which structures would be the most nonpolar? 61) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about the solubility of functional groups in water. • What type of thinking is required? o You are being asked to apply your knowledge of functional groups to predict which would be most soluble in water. • What key words does the question contain and what do they mean? o Most soluble in water: the amino acid dissolves well in water. Gather Content • What do you know about solubility in water? How does it relate to the question? o The more polar a molecule is, the better it can dissolve in water. The more nonpolar functional groups a molecule has, the less soluble it will be in water. Consider Possibilities • What other information is related to the question? Which information is most useful? o All four of the amino acids will have the same backbone structure with an amino group, an α-carbon, and a carboxyl group. The differences will be with the structure of the side chains. o Three of the amino acids have nonpolar side chains: glycine (H), valine (C3H7), and leucine (C4H9). While none of these have polar groups, leucine has the most carbons and will be the most nonpolar and hydrophobic. This will make it the least soluble in water. Choose Answer • Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer? o Serine is the only amino acid with a polar side chain (CH2OH), and the hydroxyl group (OH) will interact well with water, making serine the most soluble in water. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the structure of an amino acid to predict its solubility. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you know the structures of the amino acid side chains? Did you know which structures would be the most polar? 62) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the net reaction for a dehydration synthesis. • What type of thinking is required? o You are being asked to analyze choices for the product of a dehydration synthesis reaction and choose the correct answer. • What key words does the question contain and what do they mean? o Dehydration synthesis: a reaction used to join monomers together to form a polymer. As each monomer is added, a molecule of water is lost, which is why it is considered a dehydration reaction. Gather Content • What do you know about dehydration synthesis? How does it relate to the question? o Dehydration synthesis is used to make polymers out of monomers. If 10 glucose molecules are joined together then it would make sense to simply multiply the number of each atom in glucose by 10 to calculate how many would be present in the polymer. Based on this you would obtain the answer C6H12O6 x 10 = C60H120O60. Consider Possibilities • What other information is related to the question? Which information is most useful? o One additional thing to consider is that a water molecule is lost as each glucose is joined together. If there are 10 glucoses joined together, there would be 9 total dehydration reactions that took place. Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Water has the chemical structure H2O. If a water molecule is lost in each dehydration reaction, a total of 9 H2O would be lost for a total loss of H18O9. The formula for the final polymer will then be: C60H120O60 H18O9 = C60H102O51 Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze a dehydration synthesis reaction to determine the chemical formula of the final product. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize that if there are 10 glucose molecules in the final polymer you would need to start by multiplying the formula of glucose by 10? Did you realize that even though there were 10 glucose molecules there would only be 9 dehydration reactions? Did you know to subtract the 9 water molecules from the formula to get the final answer? 63) D 64) D
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Clarify Question • What is the key concept addressed by the question? o The question asks which biological molecule contain phosphorus. • What type of thinking is required? o You are being asked to apply your knowledge of the atoms found in different biological molecules to predict which could not be made by plants in a shortage of phosphorus. • What key words does the question contain and what do they mean? o Phosphorus shortage: molecules that contain phosphorus may not be made by the plant. Gather Content • What do you know about molecules that contain phosphorus? How does it relate to the question? o The primary molecules in cells that contain phosphorus are nucleic acids. Consider Possibilities • What other information is related to the question? Which information is most useful? o The word carbohydrate has the roots carbo- (carbon) and hydrate (water). Carbohydrates all have the base structure CH2O repeated many times, and do not contain phosphorus. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o DNA is deoxyribonucleic acid and contains nucleotides connected Version 1
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together by phosphates. The other options are all carbohydrates and do not contain phosphate. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to consider the structure of different biological molecules to determine which would contain phosphate. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize that the carbohydrates do not contain phosphate and only contain C, H and O? Did you remember that DNA is a nucleic acid and contains phosphate? 65) C 66) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about the role of the aldehyde groups in glucose in the formation of starch. • What type of thinking is required? o You are being asked to analyze the results of an experiment to explain the structure of starch. • What key words does the question contain and what do they mean? o Benedict’s test: detects aldehyde on glucose. o Aldehyde on glucose: this reacts with Benedict’s reagent and is also used to join other glucose molecules to form starch and with fructose to form sucrose. Gather Content • What do you know about the structure of starch? How does it relate to the question? o Starch is formed from multiple glucose molecules joined together through the aldehyde on one glucose and a hydroxyl group on another. Thus the aldehyde group is no longer present on a glucose molecule when it is in starch. Consider Possibilities • What other information is related to the question? Which information is most useful? o Once a starch molecule is broken down into glucose the glucose molecules contain the aldehyde group and can react with Benedict’s reagent again. Thus the aldehyde group and the glucose molecule are not permanently altered.
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Even though there are many glucose molecules in a molecule of starch, most of these will have lost their aldehyde group when they were joined to the next glucose. Only the glucose at the end of the starch will have a free aldehyde to react with the Benedict’s reagent. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze the results of an experiment to explain the structure of starch. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you understand that the aldehyde group on a glucose is lost when it forms a bond with another glucose molecule to form starch? Did you realize that this reaction is reversible, so no permanent changes to the glucose occur? Based on the structure of starch, did you understand that the glucose on the end of the starch molecule still has a free aldehyde? 67) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the nature of amino acids in a membrane. • What type of thinking is required? o You are being asked to apply your knowledge of the properties of amino acid side chains to predict which would be found in a membrane. • What key words does the question contain and what do they mean? o R groups: the side chains of amino acids. These can be polar or nonpolar. o Interior of biological membranes: a hydrophobic, nonpolar environment. Gather Content • What do you know about proteins in membranes? How does it relate to the question? o Membranes contain lipids and are hydrophobic, nonpolar environments. Amino acids with side chains that are nonpolar or hydrophobic will be more soluble in this environment. Consider Possibilities • What other information is related to the question? Which information is most useful? o R groups that are hydrophilic, polar or able to form ionic bonds will all be soluble in water. These will not be soluble in a lipid membrane. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o R groups that are hydrophobic are repelled by water and will be the most soluble in the membrane. Because of this, proteins that span membranes contain long stretches of hydrophobic or nonpolar amino acids. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to consider the properties of different amino acid R groups to predict which would be present in a biological membrane. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you have trouble recalling that a biological membrane contains lipids and is thus hydrophobic and nonpolar? Did you understand that nonpolar amino acid R groups would be more soluble in a lipid membrane? Did you realize that the other options were all R groups that would be soluble in water and not in a membrane? 68) E
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Clarify Question • What is the key concept addressed by the question? o The question asks about nonpolar molecules. • What type of thinking is required? o You are being asked to apply your knowledge of the polarity of different macromolecules to predict which would bind to a dye. • What key words does the question contain and what do they mean? o Sudan IV: a dye that binds to nonpolar molecules and turns those samples a color. Gather Content • What do you know about nonpolar molecules? How does it relate to the question? o Nonpolar molecules are hydrophobic and do not dissolve in water. Lipids and fats are common nonpolar biological molecules. Consider Possibilities • What other information is related to the question? Which information is most useful? o Hemoglobin is a protein found in blood, which is a water based solution, so it is a hydrophilic and polar molecule. o Chitin and starch are complex carbohydrates with lots of hydroxyl groups, they are hydrophilic and polar molecules. o DNA is highly charged and also a polar and hydrophilic molecule. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o Fats are nonpolar hydrophobic molecules, so they will bind to Sudan IV and turn any foods containing fats a color. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to consider the properties of a macromolecule to determine if it would bind to a hydrophobic dye. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall what nonpolar meant? Could you remember which biological molecules were nonpolar and which were polar? 69) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about the number of water molecules produced in a dehydration synthesis reaction. • What type of thinking is required? o You are being asked to analyze a reaction to predict the number of water molecules produced. • What key words does the question contain and what do they mean? o Triglyceride: contains a glycerol backbone with three fatty acid tails. Gather Content • What do you know about triglycerides? How does it relate to the question? o Glycerol is a 3 carbon sugar with 3 hydroxyl (OH) groups. Each of these OH groups reacts with a fatty acid, forming a triglyceride. In each of these steps a water molecule is released in a dehydration synthesis reaction. It is dehydration because water is released, it is a synthesis, because you are making triglyceride from glycerol and fatty acid. Consider Possibilities • What other information is related to the question? Which information is most useful? o The “tri” in triglyceride refers to the three fatty acids attached to the glycerol. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o Because fatty acids are attached to glycerol through a dehydration reaction, one water molecule is released with each reaction. Three fatty acids are attached to glycerol to form one triglyceride, so three water molecules would be released. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze a reaction to predict the number of water molecules produced. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize that this is a dehydration synthesis reaction? Did you recall that three fatty acids are added to the glycerol? Did you understand that one water molecule would be released as each fatty acid was attached to glycerol? 70) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the role of a 3’ OH group in the formation of phosphodiester bonds. • What type of thinking is required? o You are being asked to analyze statements about why a nucleotide lacking a 3’ OH group would serve as an antiviral drug. • What key words does the question contain and what do they mean? o Antiviral chemical: a drug that kills viruses. o 3’ OH group: a hydroxyl group on the deoxyribose sugar of a nucleotide. It is used to form phosphodiester bonds between adjacent nucleotides on a strand of DNA. Gather Content • What do you know about the synthesis of DNA? How does it relate to the question? o In the synthesis of DNA, the new strand grows from the 3’ end. The free 3’ OH group attacks the phosphate on the next nucleotide to be added, forming a phosphodiester bond. If the growing end lacks a 3’ OH group then no new nucleotides can be added. Consider Possibilities • What other information is related to the question? Which information is most useful? o Proteins and carbohydrates do not contain phosphodiester bonds, so these would not be affected by Acyclovir. Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o When Acyclovir is incorporated into a strand of viral DNA that strand now lacks a 3’ OH group. As a result it cannot add the next nucleotide because it cannot form a phosphodiester bond. Viral DNA replication ends where the Acyclovir was introduced into the viral DNA and the infection stops. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze explanations for how a nucleotide lacking a 3’ OH group would function as an antiviral drug. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize the role of the 3’ OH group in the formation of a phosphodiester bond? Did you know that phosphodiester bonds are found in nucleic acids like DNA but not in proteins or carbohydrates? Did you predict that the lack of a 3’ OH group would inhibit viral replication? 71) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the differences in glucose found in starch and cellulose. • What type of thinking is required? o You are being asked to apply your knowledge of the structures of starch and cellulose to explain the differences between these two forms of carbohydrate. • What key words does the question contain and what do they mean? o α-glucose and β-glucose: both of these are chemically identical glucose molecules, but they differ in how their OH groups are oriented. o Synthesize ATP: this means that the glucose can be broken down and metabolized. Gather Content • What do you know about the structure of carbohydrates? How does it relate to the question? o Complex carbohydrates like glycogen, starch, cellulose and chitin are synthesized by joining glucose molecules together into long chains. Consider Possibilities • What other information is related to the question? Which information is most useful? o Complex carbohydrates used to store energy include starch (plants) and glycogen (animals). These contain α-glucose joined together. These α-glucose monomers can be broken off by enzymes and used to make ATP. o Structural complex carbohydrates include cellulose (plants) and chitin (animals). These contain β-glucose joined together. These β-glucose Version 1
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monomers cannot be broken off by enzymes, which is why these carbohydrates are structural. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o α-glucose and β-glucose are chemically identical glucose molecules called stereoisomers which differ in how their OH groups are oriented. o α-glucose and β-glucose can both form polysaccharides when in their ring form. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to consider the structure of a polysaccharide to explain some of its properties. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that both structural and energy storing forms of complex carbohydrates are made of glucose? Did you remember that α-glucose contains bonds that can be broken by enzymes while β-glucose does not? 72) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the composition of different polymers. • What type of thinking is required? o You are being asked to apply your knowledge of which atoms are found in different monomers to a specific example. • What key words does the question contain and what do they mean? o Radioactive isotope of sulfur: an atom of sulfur with an extra neutron. It can go through radioactive decay. o Radioactively labeled: growing cells in the presence of the radioactive sulfur will incorperate the special sulfer into newly synthesized cell products that would normally contain sulfur. They are now radioactive. Gather Content • What do you know about the composition of different monomers? How does it relate to the question? o Lipids and carbohydrates contain only carbon, oxygen and hydrogen. o Nucleic acids contain nitrogen, carbon, oxygen and hydrogen. o Amino acids contain sulfur, nitrogen, carbon, oxygen and hydrogen. Consider Possibilities • What other information is related to the question? Which information is most useful? o The only monomers that contain sulfur are the amino acids cysteine and methionine. Choose Answer • Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer? o Because the amino acids cysteine and methionine are the only sulfur containing monomers, only proteins will become radioactively labeled with 35S. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to consider the composition of amino acids to explain why only proteins would be labeled with 35S. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you understand what was meant by radioactively labeling a cell? Did you recall that only the amino acids methionine and cysteine contain sulfur? 73) C
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Clarify Question • What is the key concept addressed by the question? o The question asks you to identify a macromolecule. • What type of thinking is required? o You are being asked to apply your knowledge of the representation of a macromolecule to identify it. • What key words does the question contain and what do they mean? o 5’ and 3’ – these refer to the ends of a strand of nucleic acid. The 5’ and 3’ refer to the OH groups on the ribose sugar that are not in a phosphodiester bond. Gather Content • What do you know about nucleic acid structure? How does it relate to the question? o The 5’ and 3’ ends are the first clue that this is a nucleic acid. Consider Possibilities • What other information is related to the question? Which information is most useful? o Carbohydrates or polysaccharides do not have a 5’ or 3’ end. o Proteins have ends that are labeled by a free amino terminus or carboxy terminus. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o While all nucleic acids have a 5’ and 3’ end, these could be either RNA or DNA. RNA has nucleotides with the abbreviations A, C, G, and Version 1
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U. DNA has nucleotides with the abbreviations A, C, G, and T. Since this sequence has T and no U it must be DNA. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the structure of a polymer to determine its type. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize that the 5’ and 3’ ends meant it was a nucleic acid? Did you notice that it had T’s and no U’s?
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Chapter 04 13e MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 1) The semifluid matrix that surrounds organelles in a cell is called the: A) ribosome. B) cytoplasm. C) stroma. D) nucleoplasm.
2) A distinctive feature of eukaryotes is the organization of tightly packaged chromosomal DNA with proteins into a membrane-bound structure called a: A) nucleolus. B) cell. C) nucleus. D) plasmamembrane.
3)
The organelle that can collect, package, modify, and transport molecules is called the: A) mitochondria. B) plasmamembrane. C) vesicle. D) Golgiapparatus.
4) Many antibiotics kill bacteria because they hinder translation by prokaryotic _________blank.
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A) nucleoids B) cytoskeleton C) ribosomes D) capsules E) cytoplasm
5)
The evolutionary process that created chloroplasts and mitochondria is: A) endosymbiosis. B) evolution. C) symbiosis. D) punctuatedequilibrium.
6) Microfilaments such as actin, microtubules, and the intermediate filaments form the cellsupporting structure called the: A) cytoplasm. B) plasmamembrane. C) cytoskeleton. D) nucleus.
7)
Integrins are glycoproteins that help link the cytoskeleton and the: A) cell wall. B) extracellularmatrix. C) cytoplasm. D) ribosomes.
8) Small cells function more effectively, because as cells become larger their surface area to volume ratio:
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A) increases. B) decreases. C) stays the same. D) is squared. E) is cubed.
9)
Organelles that breakdown hydrogen peroxide into water and oxygen are: A) lysosomes. B) plastids. C) vacuoles. D) liposomes. E) peroxisomes.
10) A circular molecule of DNA devoid of any histone proteins describes the chromosome of a (an): A) bacteria B) protozoa C) insects D) flowering plants E) yeasts
11)
Who first described cells? A) Darwin B) Golgi C) Linnaeus D) Hooke E) Leeuwenhoek
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12)
Schleiden and Schwann stated the "cell theory," which in its modern form says:
A) all organisms arecomposed of one or more cells, all cells require oxygen and all cells arise bydivision of other cells. B) all organisms arecomposed of one or more cells, all cells are the smallest livingthings and all cells arise by division of other cells. C) all cells willarise spontaneously, all cells require oxygen and all cells are composed of oneor more cells. D) all organisms arecomposed of one or more cells, all cells arise spontaneously and all cellsvary in size and shape.
13) The "X" shaped chromosomal hereditary material can be packaged in this organelle in eukaryotic cells but not in prokaryotic cells. This organelle is the: A) mitochondria. B) chloroplast. C) nucleoid. D) nucleus. E) ribosomes.
14) The peptidoglycan of bacterial cell walls contains a carbohydrate matrix linked together by short chains of: A) amino acids. B) fatty acids. C) nucleotides. D) water molecules. E) steroids.
15)
Prokaryotic cell movement is attributed to:
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A) capsules. B) ribosomes. C) pili. D) cytoskeletonproteins. E) flagella.
16)
Photosynthetic pigments in bacteria are located in the: A) nuclei. B) chloroplasts. C) cell wall. D) plasmamembrane. E) plasmids.
17) Plant cells often have a large membrane-bound sac that is used for storing water and other substances called a: A) nucleus. B) chloroplast. C) Golgi body. D) centriole. E) central vacuole.
18)
This cellular structure lacks a membrane: A) endoplasmic reticulum B) microbody C) Golgi body D) nucleoid E) nucleus
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19)
Some of the functions of the eukaryotic organelles are performed in bacteria by the: A) plasmamembrane. B) nucleoid area. C) cell wall. D) capsule. E) flagella/cilia.
20) The cytoplasmic space in eukaryotic cells is occupied by many diverse membrane-bound structures with specific cellular functions called: A) flagella. B) organelles. C) cilia. D) chromosomes. E) receptors.
21)
Ribosomes are made up of: A) only DNA molecules. B) only RNA molecules. C) DNA and RNA. D) only protein molecules. E) protein andRNA.
22) The eukaryotic organelle that is directly involved in the transport of proteins synthesized on the surface of the rough ER is called the: A) mitochondrion. B) vacuole. C) smooth ER. D) Golgi body. E) nucleus.
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23)
In eukaryotes, mitochondria are the organelles primarily involved in: A) energy release/capture. B) phospholipid assembly. C) export of enzymes. D) lipid synthesis. E) protein synthesis.
24)
The major histocompatibility complex is important in a T-cell's ability to: A) recognize specificbacteria. B) recognize specificviruses. C) recognize self fromnonself. D) recognize specificparasites.
25)
Nuclear pores permit the passage of all the following except: A) RNA onlyoutward. B) proteins inwardand outward. C) DNA moleculesonly outward.
26)
The nucleolus is the site of: A) protein synthesis. B) ribosome assembly. C) chromosome replication. D) lipid synthesis. E) uncoiling and unraveling of chromosomes.
27) Chromosomes can be condensed into compact structures, visible with the light microscope, but usually only: Version 1
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A) after the cell is dead. B) during cell division. C) while the DNA is being copied into RNA. D) while the proteins are being assembled. E) while the nuclear pores are open.
28) A doctor diagnosis a child with adrenoleukodystrophy (ALD) a disorder in which there is an accumulation of long fatty acid chains accumulating in the cells of the central nervous system. The issues arise with malfunctions in enzymes associated with which organelle? A) Golgi bodies B) ribosomes C) vacuoles D) peroxisomes E) endoplasmicreticulum
29)
Peroxisomes are examples of: A) chromosomes. B) lysosomes. C) microbodies. D) nucleosomes. E) ribosomes.
30)
Mitochondria and chloroplasts are the other organelles besides the nucleus that contain: A) DNA. B) pores. C) channels. D) plasma membranes. E) pigments.
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31) The organelle involved in the oxygen-requiring process by which the energy harvested from macromolecules is used to generate ATP is the: A) nucleus. B) lysosome. C) ER. D) mitochondria. E) chloroplasts.
32)
Cilia and flagella of eukaryotic cells are composed of: A) microtubules in a 9+ 2 arrangement. B) actin filaments in a 9 + 2 arrangement. C) protein fibers in a helical arrangement. D) nine triplets of microtubules in a circle.
33)
The distinctive feature of chloroplasts is that they contain a green pigment called: A) Gram stain. B) chlorophyll. C) hemoglobin. D) chromatin. E) keratin.
34) The spreading of cancer cells, wound healing, and blood clotting all rely on the same type of cell movement called: A) swimming. B) crawling. C) whipping. D) waving.
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35) A team of researchers is studying the external structures on the dorsal (back) surface of a spider mite. The spider mite seems to be the habitat of an even smaller mite, which is approximately 0.05mm. While they can see the dorsal surface of the spider mite with their naked eye, they cannot see the mite clearly. The researchers are writing a grant to provide support for a microscope to use to study these new mites. They need to purchase a microscope with a high magnification to observe the new mites on their habitat. Based on the information given, what type of microscope would you suggest? A) transmission electron microscope B) scanning electron microscope C) binocular compound light microscope D) no microscope is powerful enough to see the smaller mite
36) A cytologist is examining a tissue under an electron microscope. He notices that the endoplasmic reticulum of each cell is extremely rough in appearance and he knows that the rough appearance is because of the ribosomes embedded there. He asks why there are so many ribosomes. You respond, A) "This tissueexports lipids and is very involved with mRNA production." B) "This tissue exports proteins to other areas of the body." C) "This tissue exports various nucleic acids, hence the large number of ribosomes present on the endoplasmic reticulum in each of those cells."
37) You stain a cell with a dye that reacts with an enzyme found in the lysosome. You would also expect to see this dye in the: A) endoplasmicreticulum. B) cytoplasm. C) nucleus. D) mitochondria.
38) A cell biologist has developed a new drug that blocks vesicle transport at the cis face of the Golgi apparatus. What will this drug prevent from happening inside a cell?
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A) The synthesis of proteins or lipids on the endoplasmic reticulum. B) The movement of the lipids and proteins from the endoplasmic reticulum to the Golgi apparatus. C) The movement of materials from the Golgi apparatus to the plasma membrane. D) The movement of vesicles from mitochondria to the Golgi apparatus.
39)
Plants, fungi and bacterial all have: A) cell walls B) chloroplasts C) nuclei D) lysosomes E) mitochondria
40) Your research project involves characterizing the expression pattern of a nuclear pore protein. After using immunohistochemistry to fluorescently label the protein, you decide that you would like to capture the data as a 3-D image. Which microscope should you use? A) phase-contrast microscope B) fluorescence microscope C) confocal microscope D) scanning electron microscope
41) Sulfolobus are archaea that are commonly found in geothermal environments, with an optimum growth temperature of about 80°C. What feature allows archaea to thrive at such temperatures? A) Archaea use theheat from their environment to produce ATP. B) Archaea are highly adaptable to changing environmental temperatures. C) Archaeal membranes contain special lipids. D) Archaea have two cell walls which helps prevent heat absorption.
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42) Alcohol consumption adversely affects the synthesis of molecules involved in protein degradation, which can eventually lead to liver damage. Given this information, which organelle in liver cells is most directly affected by alcohol consumption? A) Nucleus B) Golgi apparatus C) Rough endoplasmic reticulum D) Lysosome
43) You have identified an enzyme that appears to be involved in the addition of palmityl group (a fatty acid) to certain proteins. Knowing that palmitoylated proteins are usually targeted for delivery to the plasma membrane, in which organelles might this enzyme be expressed? A) Golgi apparatus and endoplamic reticulum B) Golgi apparatus and nucleus C) Endoplamic reticulum and ribosomes D) Endoplamic reticulum and nucleus
44) Given what is known about the minimal essential functions of cellular life, if you could create an artificial cell, what cellular structures must you include? A) cell wall B) ribosomes C) mitochondria D) nucleus
45) When a vesicle moves along microtubules toward the center of the cell, the molecular motor(s)_________blank are used?
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A) kinesin B) dynein C) both kinesin and dynein D) Molecular motors are not required for movement along microtubules.
46) A protein that is destined to reach the plasma membrane is making its way through the Golgi. At that moment, a drug was added to cells, blocking trafficking at the trans face of the Golgi. As a result, what would happen to the protein? A) Theprotein would continue on to the cell surface. B) The protein wouldbe stuck in the Golgi. C) The protein would return to the endoplasmic reticulum via the trans face of the Golgi. D) Theprotein would exit the Golgi, but instead be targeted to thecytoplasm.
47) If you were to use antibodies that were chemically bonded to a stain in order to visualize the expression pattern of a protein in a fixed tissue, what experimental techniques and equipment would be applicable? A) immunohistochemistry, bright-field microscopy B) DAPI or Hoechststains, fluorescence microscopy C) antibody interference assay, bright-field microscopy D) immunohistochemistry, dark-field microscopy
48)
During which cellular process do all three forms of RNA associate? A) ribosome assembly B) chromatin formation C) formation of the nucleolus D) protein synthesis
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49) Cardiac muscle cells are connected by special junctions called intercalated discs. Intercalated discs provide strength between cells of tissues which exhibit high mechanical stress, strong flexible connections between tissue cells, and electrical excitability between the cells. Using this information, which junctions are present in intercalated discs? A) Tight, plasmodesmata, and adherens B) Tight, plasmodesmata, and desmosomes C) Gap, adherens, and desmosomes D) Gap, desmosomes, and hemidesmosomes E) Adherens, tight, and gap
50) Based on the function of mitochondria, what substance is able to pass through the outer membrane of the mitochondria easily? A) Oxygen B) Sugars C) Amino acids D) Potassium ions
51) Individuals that are heavy smokers may eventually have trouble clearing the mucous from their lungs because the structures that move fluid along the epithelial lining of the lung become damaged over time. What are these structures called? A) Pili B) Flagella C) Cell walls D) Cilia
52) Streptomycin is an antibiotic that interferes with the function of the 30S subunit of the prokaryotic ribosome. What is the consequence of treating a bacteria with streptomycin?
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A) Impaired oxygen synthesis B) Impaired protein synthesis C) Impaired DNA synthesis D) Impaired ATP synthesis
53) A dish of cells is treated with centrinone, a centriole inhibitor. These cells would no longer be able to _________blank. A) make ATP B) produce lysosomes C) synthesize proteins D) conduct photosynthesis E) divide
54) When looking at plant and animal cells with an electron microscope, you notice that the plant cells have more Golgi membranes than the animal cells. This is most likely because unlike in animal cells, in plant cells the Golgi apparatus is involved in the production of: A) cell walls. B) cytoplasm. C) chloroplasts. D) mitochondria.
55) Glycogen Storage Disease Type II (GSD II), also known as Pompe disease, is a metabolic disorder that leads to the accumulation of glycogen in muscles and neurons throughout the body. It is caused by a defect in an enzyme that is normally housed with other enzymes that are involved in breaking down large macromolecules. What organelle is most likely affected by this disease?
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A) Mitochondrion B) Golgi body C) Lysosome D) Rough ER E) Nucleus
56) Scientists believe that stimulating growth of algae and other organisms can reduce carbon dioxide amounts in the atmosphere. Where is carbon dioxide consumed in a plant cell? A) Stroma in chloroplasts B) Matrix in mitochondria C) Number ofamyloplasts D) Central vacuole E) Cellulose in cell wall
57) Cardiac muscle has prolonged contraction due to a sodium induced-calcium released process into the cytoplasm of the cell. Cardiac cells can communicate through pore-like channels between cells. List the junction and the organelle involved in cardiac muscle contraction? A) Gap; Rough ER B) Gap; Smooth ER C) Gap; Golgiapparatus D) Adherens; RoughER E) Adherens; SmoothER F) Adherens; Golgi apparatus
58)
Mitochondrial disorders can be caused by mutations in all the following except: A) mitochondrialDNA B) nuclear DNA C) cytoplasmicDNA
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59)
What is the difference between mitochondria and chloroplasts?
A) Mitochondria havethree membranes and chloroplasts have two membranes. B) Mitochondria have linear strands of DNA and chloroplasts have rings of DNA. C) Mitochondria are oxidative metabolic bacteria derivatives and chloroplasts are photosynthetic bacteria derivatives. D) Mitochondria produce oxygen and chloroplasts produce carbon dioxide.
60) If a water molecule passes through the outer membrane of a chloroplast, how many more membranes will it have to move through to be in the stroma? A) 1 B) 2 C) 3 D) 4
61) As ATP moves from the matrix of the mitochondrion to the cytoplasm of a cell, how many membranes will it pass? A) 1 B) 2 C) 3 D) 4
62)
Prokaryotic cells are smaller than eukaryotic cells. What is a plausible explanation? A) Prokaryotic cell walls limit their cell growth. B) Prokaryotes lackthe genetic material needed for protein synthesis. C) Eukaryotes havecompartmentalization, which allows for specialization. D) Prokaryotes have more diverse energy sources. E) Eukaryotes are immobile allowing themto grow larger.
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63) A cuboidal shaped cell with six sides is 1mm x 1mm x 1mm. What is the volume and the surface area of the cell? A) 1mm3 : 6mm2 B) 3mm3 :3mm2 C) 1mm3 :3mm2 D) 3mm3 :1mm2
64) Matthew noticed that his house plants were wilting badly. Which cell structure had most likely contracted? A) cytoplasm B) cell wall C) plasma membrane D) vacuole
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Answer Key Test name: Chap 04_13e_Raven 1) B 2) C 3) D 4) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about inhibition of translation. • What type of thinking is required? o You are being asked to apply your knowledge of translation to explain how an antibiotic works. • What key words does the question contain and what do they mean? o Antibiotic – a drug that kills bacteria. o Translation – conversion of the information in mRNA into protein. Gather Content • What do you know about translation? How does it relate to the question? o Translation occurs when ribosomes pair the anticodon on a transfer RNA with the codon on a messenger RNA. The transfer RNAs each carry an amino acid, and these are joined together to form a protein. Consider Possibilities • What other information is related to the question? Which information is most useful? o None of the other organelles listed are involved in translation. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If translation is blocked by a drug it most likely affects the ribosome. Reflect on Process Version 1
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the role of the ribosome to predict the mechanism by which an antibiotic kills bacteria. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that translation involved converting mRNA into protein? Did you understand that the ribosome was the enzyme that catalyzed the synthesis of proteins? 5) A 6) C 7) B 8) B 9) E 10) A 11) D 12) B 13) D 14) A 15) E 16) D 17) E 18) D 19) A 20) B 21) E 22) D 23) A 24) C 25) C Version 1
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26) B 27) B 28) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about accumulation of fatty acids. • What type of thinking is required? o You are being asked to apply your knowledge of the breakdown of fatty acids to explain a disease. • What key words does the question contain and what do they mean? o Long chain fatty acids accumulate – this could be due to increased synthesis or decreased breakdown. o Malfunctions of enzymes – if an enzyme is not working it has a decrease in activity. Gather Content • What do you know about fatty acid accumulation in cells? How does it relate to the question? o A decrease in enzymes used to break down fatty acids would result in an increase of these fatty acids in a cell. This is most likely because the enzyme cannot cleave the fatty acids any more. Consider Possibilities • What other information is related to the question? Which information is most useful? o Endoplasmic reticulum and ribosomes are used in protein synthesis. The Golgi is involved in protein transport. Vacuoles are used to store water and carbohydrates in cells. Choose Answer • Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer? o Peroxisomes contain enzymes used to digest fatty acids. If an enzyme needed to break down fatty acids was missing from the peroxisome then fatty acids would accumulate in the cell. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of the role of the peroxisome in a disease. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize that a decrease in the amount of enzyme would cause an accumulation of the substrate it normally cleaved? Did you recall the function of the other organelles listed? 29) C 30) A 31) D 32) A 33) B 34) B 35) C 36) B 37) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about an enzyme in the lysosome. • What type of thinking is required? o You are being asked to apply your knowledge of how proteins move into the lysosome to explain the results of an experiment. • What key words does the question contain and what do they mean? o Dye that reacts with an enzyme found in the lysosome – there are specific stains that bind one protein and not another. Gather Content • What do you know about lysosome proteins? How does it relate to the question? o Enzymes from the lysosome are first made in the endoplasmic reticulum, where they move through the Golgi, and then on to the lysosome. Consider Possibilities • What other information is related to the question? Which information is most useful? o Proteins are not made in the nucleus. o Proteins made in the cytoplasm remain in the cytoplasm. o Some proteins are made in the mitochondria, but remain there. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Proteins that are secreted or transported into organelles like the Version 1
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lysosome are first made in the endoplasmic reticulum. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of protein secretion to explain where an enzyme in the lysosome was made. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that proteins made in the endoplasmic reticulum are transported to other organelles like the lysosome? Did you think that proteins made in the cytoplasm could cross a membrane and enter an organelle like the lysosome? 38) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the role of the cis Golgi. • What type of thinking is required? o You are being asked to analyze an experiment to explain the effect of a drug that would block vesicle transportin the cis Golgi. • What key words does the question contain and what do they mean? o Cis Golgi – the Golgi is made up of parallel stacks of membrane with a cis face closest to the endoplasmic reticulum and a trans face closest to the plasma membrane. o Vesicle transport – vesicles are small lipid spheres that transport proteins from one organelle to another. Gather Content • What do you know about vesicle transport? How does it relate to the question? o Proteins made in the endoplasmic reticulum are packaged in vesicles and transported to the cis Golgi. In the Golgi the proteins have carbohydrates added. Next the proteins are packaged into vesicles that bud off of the trans Golgi for transport to the plasma membrane or other organelles. Consider Possibilities • What other information is related to the question? Which information is most useful? o Lipids are made in the smooth endoplasmic reticulum, but this would not affect vesicle transport. o Movement of vesicles to the plasma membrane comes from the trans Golgi. Version 1
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o Vesicles don’t move from the mitochondria to the Golgi. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The best answer is that vesicles released from the endoplasmic reticulum would not be able to fuse with the cis Golgi. Proteins and lipids made in the endoplasmic reticulum would not be able to enter the Golgi apparatus if the drug blocked this step. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze the results of an experiment to predict the impact of a drug that blocks transport through the cis Golgi. To do this you needed to understand the function of the cis Golgi and then what would happen if this function was blocked. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall the function of the cis Golgi? Did you confuse it with the trans Golgi? Did you recall the function of the cis Golgi, but could not predict what would happen if the drug blocked the cis Golgi? 39) A 40) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about choosing the correct type of microscope for an experiment. • What type of thinking is required? o You are being asked to apply your knowledge of the properties of different microscopes to choose the correct instrument for an experiment. • What key words does the question contain and what do they mean? o Fluorescently label – this refers to using a fluorescent tag to make a protein visible with a fluorescence microscope. o 3-D image – a three-dimensional image taken by either looking at the surface of an object, or by taking images through multiple planes or compiling them together. Gather Content • What do you know about different types of microscopes? How does it relate to the question? o Fluorescence microscope – detects fluorescence, but only looks at one plane of focus. o Scanning electron microscope – bounces electrons off of the surface of an object to make a 3-D image. o Phase-contrast microscope – uses polarized light to view cells. o Confocal microscope – detects fluorescence and compiles multiple planes together to make a 3-D image. Consider Possibilities • What other information is related to the question? Which information is most useful? Version 1
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o Some of the options will detect fluorescence and some will make 3-D images. However, only one option will do both. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o A confocal microscope is the best option in this case as it will detect fluorescence and allow you to create a 3-D image by stacking multiple images together. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of the properties of different microscopes to decide which would be the best option to create a 3-D fluorescent image. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you have trouble remembering how each type of microscope works? Did you pick an option that could generate a 3-D image but did not work with fluorescent molecules? Did you pick an option that would work with fluorescent molecules but not generate a 3-D image? 41) C 42) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about the organelle involved in making enzymes used in protein degradation. • What type of thinking is required? o You are being asked to apply your knowledge of the function of organelles to explain how alcohol can block the production of enzymes used to break down proteins. • What key words does the question contain and what do they mean? o Synthesis of molecules involved in protein degradation – proteins are broken down in a cell by enzymes found in the lysosome. These enzymes are made in the endoplasmic reticulum and transported to the lysosome. Gather Content • What do you know about where lysosome proteins are made? How does it relate to the question? o The enzymes in the endoplasmic reticulum are made in the endoplasmic reticulum and transported to the lysosome. Once in the lysosome these enzymes can break down proteins. Consider Possibilities • What other information is related to the question? Which information is most useful? o The key to this question is that alcohol blocks the synthesis of the enzymes used in protein degradation. Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The best answer is that alcohol blocks the endoplasmic reticulum from producing enzymes that move to the lysosome to degrade proteins. A common mistake would be to choose the lysosome, and if the question had stated that alcohol blocked the molecules involved in protein degradation this would be correct. However, the question states that alcohol blocks the synthesis of these molecules which occurs in the endoplasmic reticulum. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of where lysosomal proteins are made to explain the effect of alcohol on the liver. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you miss that the question was asking where the synthesis of enzymes involved in protein degradation was occurring? Did you think that alcohol was inhibiting the enzymes themselves and not their synthesis? Did you recall that proteins are made in the endoplasmic reticulum? 43) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about the transport of proteins to the plasma membrane. • What type of thinking is required? o You are being asked to apply your knowledge of protein transport in a cell to predict the location of an enzyme involved in the process. • What key words does the question contain and what do they mean? o Palmityl group (a fatty acid) – this fatty acid can be attached to proteins by specific enzymes. Attaching a fatty acid to a protein will make it more hydrophobic and likely to be embedded in a membrane. o Delivery to the plasma membrane – proteins targeted for delivery to the plasma membrane are made in the endoplasmic reticulum and then move through the Golgi and on to the plasma membrane through vesicles. Gather Content • What do you know about protein transport to the plasma membrane? How does it relate to the question? o Proteins targeted for delivery to the plasma membrane are made in the endoplasmic reticulum and then move through the Golgi and on to the plasma membrane through vesicles. Consider Possibilities • What other information is related to the question? Which information is most useful? o Ribosomes are large enzymes used to synthesize proteins by translating a messenger RNA. o The nucleus contains DNA and is where transcription to synthesize Version 1
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RNA occurs. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Proteins targeted for delivery to the plasma membrane are made in the endoplasmic reticulum and then move through the Golgi and on to the plasma membrane through vesicles. An enzyme that attaches fatty acids to proteins targeted for the plasma membrane would be found in the endoplasmic reticulum or Golgi. Addition of the fatty acid would make the protein more hydrophobic and bind to the membrane in the vesicle and eventually the plasma membrane. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of protein secretion to predict where an enzyme would be found. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall which organelles were involved in protein secretion? Did you realize that adding a fatty acid to a protein would make the protein more hydrophobic and bind to a membrane? Did you think that the nucleus was involved in protein secretion? 44) B 45) B 46) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the function of the trans Golgi. • What type of thinking is required? o You are being asked to analyze the design of an experiment to predict what would happened if a drug blocked transport from the trans Golgi. • What key words does the question contain and what do they mean? o A protein destined to reach the plasma membrane – this is a protein in the secretory pathway from the endoplasmic reticulum to the Golgi to the plasma membrane o Trans Golgi – this is the part of the Golgi facing the plasma membrane. The cis Golgi faces the endoplasmic reticulum. Gather Content • What do you know about transport to the plasma membrane? How does it relate to the question? o Proteins targeted for the plasma membrane are first made in the endoplasmic reticulum and are then transported through vesicles to the cis Golgi. The proteins then leave through the trans Golgi to be transported to the plasma membrane. Consider Possibilities • What other information is related to the question? Which information is most useful? o The drug that blocks transport from the trans Golgi is added right when a protein is in the Golgi. This means that proteins would not be able to enter vesicles from the Golgi and would be blocked from moving to the plasma membrane.
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Proteins leave the Golgi through the trans Golgi, so if this step is blocked the proteins will accumulate in the Golgi. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze an experiment and predict what would happen if a drug was added that blocks transport from the trans Golgi. To do this you needed to understand that the trans Golgi is where proteins leave the Golgi for the plasma membrane. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall where the trans Golgi was or its function? Did you understand that a drug blocking the trans Golgi would prevent proteins from leaving the Golgi and getting to the plasma membrane? 47) A 48) D 49) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about the types of junctions found in an intercalated disk. • What type of thinking is required? o You are being asked to apply your knowledge of the attributes found in each junction to predict which would be present in an intercalated disk. • What key words does the question contain and what do they mean? o Junctions called intercalated disks – junctions are structures found between cells. They can be adhesive – holding cells together, or communicating – allowing cells to send electrical impulses or compounds between adjacent cells. Gather Content • What do you know about junctions? How does it relate to the question? o There are several classes of junctions with different functions. ●● Tight junctions prevent molecules from passing between cells, for example in the lining of the intestines. ● Adherens junctions connect cells together in areas of high mechanical stress that need to stretch like the skin ● Desmosomes create strong flexible connections for tissues that need to move yet be strong such as the skin. ● Hemidesmosomes are involved in cell migration and are important in development. ● Gap junctions create a pore between adjacent cells that allows small molecules to move from one cell to another, important in transmitting Version 1
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electrical impulses between muscle cells. ● Plasmodesmata are junctions found in plant cells that allow cytoplasmic proteins to be exchanged between cells. Consider Possibilities • What other information is related to the question? Which information is most useful? o Plasmodesmata are found in plants and would not be in heart tissue. o The heart muscle cells do not need to prevent molecules from moving between the cells, so they would not need gap junctions. o Heart cells do not need to migrate, so they would not require hemidesmosomes. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Because heart muscle cells need to contract and relax constantly for the life of the organism, the cells must be connected by strong flexible connections capable of withstanding high mechanical stress. Desmosomes and adherens junctions are capable of these two functions respectively. In addition, once a region of the heart starts to contract, that electrical impulse must move through the wall of the heart so all of the muscle beats in a smooth rhythm. Gap junctions allow signaling molecules to move from one heart muscle cell to the next carrying this message and keeping the heart in rhythm. Reflect on Process • Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the definitions of different types of junctions to predict which would be present in the intercalated disks holding heart muscle cells together. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you have trouble recalling the definitions of the different cellular junctions? Did you realize that there were three different junctions being described in the question? 50) A 51) D 52) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the function of the ribosome. • What type of thinking is required? o You are being asked to apply your knowledge of the function of a ribosome to explain what would happen to a cell if this function were inhibited. • What key words does the question contain and what do they mean? o 30S subunit of the prokaryotic ribosome – prokaryotes (bacteria) have ribosomes with two halves, the smaller 30S subunit and a larger 50S subunit. The “S” is a measure of size based on how the ribosome sediments in a centrifuge. o Streptomycin – this is an antibiotic that blocks the function of the 30S subunit. Antibiotics are used to kill bacteria. Gather Content • What do you know about the ribosome? How does it relate to the question? o Because streptomycin inhibits the 30S subunit of the ribosome, the ribosome will no longer be able to function properly. The function of the ribosome is to synthesize proteins from a messenger RNA in translation. Consider Possibilities • What other information is related to the question? Which information is most useful? o The ribosome is not directly involved in oxygen, DNA, or ATP production in a cell. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The best answer is that inhibition of the 30S subunit of a ribosome by streptomycin will block translation of a mRNA and thus impair protein synthesis. If a bacteria cannot make new proteins then it will not be able to divide, and will eventually die. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge of the function of a ribosome to explain how streptomycin would work as an antibiotic. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recognize that because the 30S subunit was part of the ribosome, if it was inhibited then the ribosome would be inhibited? Did you remember that the ribosome is involved in protein synthesis, so if the ribosome was inhibited protein synthesis would be impaired? 53) E
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Clarify Question • What is the key concept addressed by the question? o The question asks about centrioles. • What type of thinking is required? o You are being asked to apply your knowledge of the function of a centriole to predict what would happen to a cell if the centrioles were inhibited. • What key words does the question contain and what do they mean? o Centrinone inhibitor – This chemical was added to cells to block the activity of the centrioles Gather Content • What do you know about centrioles? How does it relate to the question? o Centrioles are found in the nucleus and they organize the microtubules that bind to chromosomes during cell division in mitosis or meiosis. Consider Possibilities • What other information is related to the question? Which information is most useful? o The drug centrinone does not affect other structures in the cell that are involved in protein synthesis, photosynthesis or ATP production. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Centrioles are involved in forming the spindles from the edges of the Version 1
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nucleus to chromosomes. These microtubule spindles then pull the chromosomes to separate ends of the cell during mitosis, an essential step in cell division. If the centrioles are inhibited then the cells cannot divide. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the function of centrioles to predict what would happen to cells in which centriole activity was blocked. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall the function of centrioles? Could you predict what would happen if centriole activity was blocked? Did you think that centrioles had one of the other functions listed? 54) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about comparing the Golgi in plant and animal cells. • What type of thinking is required? o You are being asked to analyze the results showing a difference in the size of the Golgi in plant and animal cells and provide an explanation. • What key words does the question contain and what do they mean? o Plant cells have more Golgi than animal cells – if an organelle is larger in one cell than another that often indicates that whatever function that organelle has in the first cell is in more demand than it is in the second cell. Gather Content • What do you know about Golgi in plant and animal cells? How does it relate to the question? o Animal cells have about 20 Golgi organelles, and these are involved in adding carbohydrates to proteins produced in the endoplasmic reticulum and being secreted or targeted to other organelles. Plant cells can have 100 Golgi organelles, and in addition to adding sugars to proteins, sugars are joined together to produce cell walls in the Golgi. Consider Possibilities • What other information is related to the question? Which information is most useful? o The Golgi do not produce other organelles, but they do make some proteins that are transported to organelles like the lysosome. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The biggest difference between plant and animal cells is that plant cells have a cell wall and animal cells do not. Cell walls are made of cellulose, which consists of many sugar residues attached to each other. The cell walls are made in the Golgi, so the plant cells need more Golgi organelles to keep up with the demand for cellulose for new cell walls. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze the results of an observation to explain why plant cells have more Golgi than animal cells. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that the cell wall is made in the Golgi of plant cells but not animal cells? Did you pick chloroplasts because they were present in plant cells but not animal cells? 55) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about the glycogen storage disorder Pompe disease. • What type of thinking is required? o You are being asked to apply your knowledge of different organelles to predict which would be involved in the breakdown of large macromolecules like glycogen. • What key words does the question contain and what do they mean? o Accumulation of glycogen – this means that glycogen is not being broken down as it is supposed to, causing it to accumulate in neurons. o Defect in an enzyme –the enzyme that normally breaks down glycogen has been mutated so that it can no longer catalyze this reaction. o The enzyme is housed with other enzymes that are involved in breaking down large macromolecules – the enzymes are housed together in an organelle. Gather Content • What do you know about breaking down large macromolecules like glycogen? How does it relate to the question? o Enzymes used to break down large macromolecules are typically housed in the lysosome. If one of these enzymes has a mutation and no longer functions then the macromolecule that it degrades will accumulate. Consider Possibilities • What other information is related to the question? Which information is most useful? o The endoplasmic reticulum and Golgi are involved in protein transport, but would not store enzymes used to break down large Version 1
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macromolecules. o The nucleus would encode genes for these enzymes, but would not contain the enzymes themselves. o Mitochondria are responsible for ATP production in the presence of oxygen. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The best answer is that these enzymes would be present in the lysosome along with other digestive enzymes. The lysosome contains many enzymes, and if any of these are defective it can lead to the accumulation of large macromolecules like glycogen. The accumulation of these large macromolecules eventually inhibit the normal function of the cell, causing a disease state in the patient. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of the functions of different organelles to explain where a defective enzyme would be located. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you understand that the question was asking for the location of enzymes involved in degrading large macromolecules? Did you think that the question was asking about where these enzymes would be made in the cell? 56) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about carbon dioxide consumption in plant cells. • What type of thinking is required? o You are being asked to apply your knowledge about different organelles to explain which would be involved in removing carbon dioxide from the atmosphere. • What key words does the question contain and what do they mean? o Reduce carbon dioxide amounts in the atmosphere – this means that increased algae growth will take carbon dioxide from the atmosphere and convert it into molecules in the algae. Gather Content • What do you know about plants using carbon dioxide? How does it relate to the question? o Plants use carbon dioxide during photosynthesis, converting carbon dioxide and water into glucose and oxygen. By increasing algae growth and photosynthesis, the theory is that carbon dioxide levels would decrease. Consider Possibilities • What other information is related to the question? Which information is most useful? o Amyloplasts and the vacuole store starch and water in plant cells. o Cellulose is made of glucose, so the carbon dioxide that is made into glucose will end up in cellulose (and in starch) eventually. However, these are the end products of the reaction, not the location where the reaction occurred. o Mitochondria are responsible for the reverse reaction, using oxygen to Version 1
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break glucose into water and carbon dioxide. So increased mitochondria would lead to increased carbon dioxide release into the atmosphere. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Photosynthesis occurs in chloroplasts, and specifically in the stroma of a chloroplast. As more algae grow they will produce more chloroplasts and more carbon dioxide will be converted into glucose, removing the carbon dioxide from the atmosphere. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of different organelles to explain why an increase in algae would lead to a decrease in carbon dioxide in the atmosphere. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you understand that the reaction that plants use to remove carbon dioxide from the atmosphere was photosynthesis? Did you know that photosynthesis occurs in the stroma of chloroplasts? Did you realize that mitochondria perform the reverse reaction and release carbon dioxide into the atmosphere? Did you think that the storage of glucose in starch or cellulose would explain the decrease in carbon dioxide in the atmosphere, although the question asked where this would occur? 57) B 58) C 59) C Version 1
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60) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about the location of the stroma in a chloroplast. • What type of thinking is required? o You are being asked to apply your knowledge of the structure of a chloroplast to explain how many membranes are present. • What key words does the question contain and what do they mean? o Outer membrane of a chloroplast – A chloroplast has two membranes, much like a mitochondria. However, unlike a mitochondria, inside of a chloroplast there are thylakoid disks which are made up of a third membrane. o Stroma – this is the fluid filled space inside the chloroplast which contains the thylakoid. Gather Content • What do you know about the structure of a chloroplast? How does it relate to the question? o A chloroplast has two membranes much like a mitochondria, an outer membrane and an inner membrane. Inside of the chloroplast is the stroma and within it are sub-organelles called thylakoids. Consider Possibilities • What other information is related to the question? Which information is most useful? o The water molecule has crossed the outer membrane, so it is in the intermembrane space between the outer and inner membranes. Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The water molecule only needs to cross the inner membrane to be in the stroma, so it must cross one membrane. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of the structure of a chloroplast to explain the movement of water across its membranes. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall the structure of the chloroplast and that it contains an outer membrane, an inner membrane and a thylakoid membrane? Did you remember where the stroma was in the chloroplast? Did you think that the question asked how many total membranes were in a chloroplast? 61) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the structure of a mitochondria. • What type of thinking is required? o You are being asked to apply your knowledge of the structure of the mitochondria to explain how many membranes an ATP molecule will cross moving from the matrix to the cytoplasm. • What key words does the question contain and what do they mean? o Matrix – the inner most space of a mitochondria. o Cytoplasm – the fluid inside of a cell but outside of the mitochondria within the cell. o Mitochondria – an organelle with two membranes involved in ATP production. Gather Content • What do you know about the structure of a mitochondria? How does it relate to the question? o Mitochondria contain two membranes, an outer and an inner membrane. The center of the mitochondria is called the matrix. Consider Possibilities • What other information is related to the question? Which information is most useful? o The ATP molecule is starting in the matrix and is moving to the cytoplasm, which is entirely outside of the mitochondria. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o Because a mitochondria has two membranes, for an ATP molecule to move from the matrix to the cytoplasm it will need to cross both the inner and outer mitochondrial membranes. Thus the ATP molecule will cross two membranes. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of the structure of a mitochondria to explain how many membranes a molecule of ATP will need to cross to move from the matrix to the cytoplasm. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you understand the structure of a mitochondria? Did you recall that a mitochondria has an inner and an outer membrane? Did you remember that the matrix is inside of the mitochondria and the cytoplasm is on the outside of the mitochondria? 62) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about the difference in size between prokaryotic and eukaryotic cells. • What type of thinking is required? o You are being asked to apply your knowledge of the structure of prokaryotic and eukaryotic cells to explain why the prokaryotic cells are smaller. • What key words does the question contain and what do they mean? o Prokaryotic cells – these are bacterial cells that contain DNA and the machinery for metabolism and replication, but no organelles. o Eukaryotic cells – these cells can be single celled organisms or part of a larger multicelled organism. They contain a nucleus and other organelles. Gather Content • What do you know about the structure of cells? How does it relate to the question? o Prokaryotic cells do not contain organelles while eukaryotic cells do contain organelles. o Eukaryotes are diverse organisms, some can move (animals and some protists) while others have cells walls (fungi, plants, some protists). Some are multicellular (plants, animals, and fungi) while some can be single celled (plants, protists, fungi). Consider Possibilities • What other information is related to the question? Which information is most useful? o While prokaryotes are single celled and do not contain organelles they Version 1
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have the normal functions of all cells, namely they can replicate, produce energy through metabolism, and have a plasma membrane. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Some eukaryotes can move and some have a cell wall. Bacteria can make proteins and their choice of energy source should not influence their size. The best answer is that eukaryotic cells all contain organelles such as a nucleus, mitochondria, chloroplasts, lysosomes, etc. These internal structures take up space making eukaryotic cells larger than prokaryotic cells. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of the differences in the cell structure of prokaryotes and eukaryotes to explain why eukaryotes are larger. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you have trouble recalling that eukaryotes have internal organelles? Did you forget that many eukaryotes can move or have cell walls like prokaryotes so this would not explain the difference in size? Did you think that prokaryotes could not make proteins, an essential function for any living cell? 63) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about the volume and surface area of a cube. • What type of thinking is required? o You are being asked to apply your knowledge of the volume and surface area of a cube to calculate both. • What key words does the question contain and what do they mean? o Volume of a cube – this is the 3-dimensional volume of the cube. o Surface area of a cube – a cube has 6 faces – think of a dice with 1 through 6 spots on each face. Gather Content • What do you know about area and volume of a cube? How does it relate to the question? o The volume of a cube is calculated by multiplying the height x width x depth of a cube. If the dimensions of the cube are given in millimeters (mm) then the final volume will be mm x mm x mm = mm3. o To calculate the surface area of a cube first calculate the area of one face of the cube. This will be the height x the width. A cube has 6 faces, so you then multiply the area of one face x 6 to calculate the total surface area. If the dimensions of the cube are given in millimeters (mm) then the final area will be mm x mm = mm2. Consider Possibilities • What other information is related to the question? Which information is most useful? o For both the volume and the area calculations remember to multiply the dimensions together, do not add them.
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The volume of the cube will be 1mm x 1mm x 1mm = 1mm3. o The area of one face of the cube will be 1mm x 1mm = 1mm2. There are 6 faces on a cube, so the total area of the cube will be 6 x 1mm2 = 6mm2. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of the volume and area of a cube to a specific example. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you have trouble remembering the formulas for the volume of a cube and the area of a cube? Did you think that you needed to add the dimensions instead of multiplying them? Did you remember that a cube has 6 faces, so you need to multiply the area of one face times 6 to calculate the entire area? 64) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about the structure of a plant cell. • What type of thinking is required? o You are being asked to apply your knowledge of the structure of a plant cell to explain what is happening inside of the cell in a wilted plant. • What key words does the question contain and what do they mean? o Wilting – this is when a plant becomes limp and droopy. o Contracted – this means to squeeze down to a smaller size. Gather Content • What do you know about the structure of a plant cell? How does it relate to the question? o Plant cells contain a plasma membrane and a cell wall. The cell wall helps maintain structural support. However, if a plant lacks enough water the leaves of the plant will wilt and become droopy. Once the plant is watered it will swell back up and stand up straight again. Consider Possibilities • What other information is related to the question? Which information is most useful? o The plasma membrane and cell wall are structural elements of a plant cell, but they do not contract or swell when a plant becomes wilted. o The cytoplasm does contain water, but it is not the primary water storage organelle in a plant. Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The primary water storage organelle in a plant is the vacuole. When a plant becomes wilted, the vacuole contracts or squeezes in. This pushes water out of the plant cell causing it to lose volume. When enough plant cells lose volume the plant itself starts to droop or wilt. When you water the plant, the cells take up the water in their vacuoles, causing the cells to swell up again. Once enough cells swell up the plant will regain its normal shape. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of the structure of a plant to explain what happens inside a cell when a plant wilts. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you understand that when a plant is wilted it is not getting enough water? Did you recall that the vacuole is responsible for storing water in a plant cell? Did you understand that when a vacuole contracts it pushes water out of the cell, causing the plant to become droopy and wilt?
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Chapter 05 13e CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 1) The cell's plasma membrane mediates which of the following transactions with the environment? Choose all that apply. A) Ingesting foodmolecules and sometimes entire cells B) Returning wasteand other molecules back to the environment C) Responding to ahost of chemical cues D) Directingsynthesis of various food-digesting proteins E) Passing messages to other cells
2) Receptor-mediated endocytosis brings in specific material by engulfing it in vesicles. What factors, either directly or indirectly, are related to this process? Choose all that apply. A) It is a passive process. B) It helps to increase membrane fluidity by helping to transport cholesterol into the cell. C) It is an active process. D) It uses carrier proteins. E) A clathrin coat is present.
3)
Choose all that apply. A concentration gradient is exhibited when
A) the room temperature is 34 degree Celsius and the outside air is 34 degrees Celsius. B) intracellular fluid has 5% solute and extracellular fluid has 0.8% solute concentration. C) during rest, muscle and liver cells contain high glycogen concentration and blood contains lower concentrations. D) the pCO2 changes from 45 to 35 mmHg in the alveoli of lungs.
4) If ATP production is blocked, decreased transport of material across a membrane occurs. Which type of transport is affected? Choose all that apply.
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A) Osmosis B) Diffusion C) FacilitatedDiffusion D) ActiveTransport E) Endocytosis
5) A symporter moves glucose and sodium from extracellular fluids into the cell. What can be concluded about the movement of glucose? Choose all that apply.
A) Glucose would bemoving against its gradient into the cell B) The gradient driving the movement of sodium powers the movement of glucose into the cell C) Glucose would bemoving with its gradient into the cell D) ATP is not required to move sodium down its concentration gradient E) Energy is neededto move glucose down its concentration gradient F) Glucose's movementwould still be considered diffusion G) Glucose's movementis considered a part of coupled transport
6) Insulin stimulates an increase of glucose carrier proteins on a cell’s surface. What effect does insulin have on cell function? Choose all that apply. A) An increase in GLUT4 receptors, which will increase the glucose diffusion rate. B) ATP amounts neededfor this transport will increase. C) Low insulin levelswill decrease the number of available carrier proteins. D) Lack of membranereceptors for insulin will decrease amount of glucose taken in.
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 7) The lipid layer that forms the foundation of cell membranes is primarily composed of molecules called __________.
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A) phospholipids B) cholesterol C) proteins D) carbohydrates
8) While water continually orients phospholipids into a lipid bilayer, it does not fix the lipids permanently into position. Thus, the bilayer is considered to be _______. A) static B) fluid C) fluctuating D) charged
9)
What describes the movement of substances down their concentration gradients? A) Bulk transport B) Active transport C) Saturation D) Diffusion
10) Osmosis is the diffusion of water across a membrane in response to the concentration of one or more of the ______. A) solutes B) membranes C) compartments D) cells
11) Which type of protein is embedded in the cell membrane for both active transport and facilitated transport?
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A) carrier B) cytoskeletal C) structural D) targeted
12) Osmosis occurs as water crosses the lipid bilayer through specialized channels for water movement called ________________. A) proteins B) transmembranecarbohydrates C) membrane pores D) aquaporins
13)
The plasma membrane is a thin sheet of lipid molecules embedded with A) proteins. B) carbohydrates. C) polymers. D) nucleotides. E) sodium and potassium ions.
14) Membrane proteins are not very soluble in water because they possess long stretches of non-polar amino acids that are A) too long tointeract with the water molecules. B) hydrophobic. C) are transmembranal. D) hydrophilic. E) used as transportchannels.
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15) If a cell has the same internal concentration of dissolved molecules as its outside environment, the cell's condition is referred to as being A) isotonic. B) hypertonic. C) hypotonic. D) hydrophobic. E) hydrophilic.
16) Transport of a solute across a membrane where the solute is going up its concentration gradient and using protein carriers driven by the expenditure of chemical energy, is known as A) osmosis. B) diffusion. C) facilitated transport. D) active transport. E) exocytosis.
17)
How are the tails and heads of membrane phospholipids oriented in their environment?
A) The hydrophobic heads are oriented toward each other and the hydrophillic tails are oriented toward the extracellular fluid and the intracellular fluid. B) The hydrophillic tails are oriented toward each other and the hydrophobic heads are oriented toward the extracellular fluid and the intracellular fluid. C) The hydrophobic tails are oriented toward each other and the hydrophillic heads are oriented toward the extracellular fluid and the intracellular fluid. D) The hydrophillic heads are oriented toward each other and the hydrophobic tails are oriented toward the extracellular fluid and the intracellular fluid.
18)
The fluid nature of the membranes is attributed to a lateral movement of
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A) protein channels. B) phospholipid molecules. C) antigen molecules. D) pumps such as the proton pump. E) the entire lipid bilayer.
19) On the outer surface of the plasma membrane there are marker molecules that identify the cell type. Often these molecules are A) ATP. B) amino acids. C) nucleotides. D) carbohydrate chains. E) inorganic ions.
20)
Which of the following protein classes are not found as membrane proteins? A) transport channels B) hormones C) receptors D) enzymes E) identity markers
21) The part of a membrane protein that extends through the phospholipid bilayer is primarily composed of amino acids that are A) highly polar. B) negatively charged. C) nonpolar. D) positively charged. E) water soluble.
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22) Red blood cells are biconcave. Their shape is determined by interior proteins anchored to the membrane termed: A) clathrins. B) phospholipids. C) spectrins. D) actinfilaments.
23) The movement of substances from regions where their concentration is higher to regions where their concentration is lower is called: A) active transport. B) diffusion. C) pinocytosis. D) pumping. E) exocytosis.
24) If two solutions have unequal concentrations of a solute, the solution with the lower concentration is called A) isotonic. B) hypertonic. C) hypotonic. D) osmosis.
25) In bacteria and cells of fungi and plants, the high internal pressure generated by osmosis is counteracted by the mechanical strength of their A) plasma membranes. B) organelles. C) cytoskeletons. D) cell walls.
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26)
The process often referred to as "cellular eating" is A) osmosis. B) pinocytosis. C) phagocytosis. D) diffusion. E) active transport.
27)
Carrier-mediated transport of a substance down its concentration gradient is called A) facilitated diffusion. B) active transport. C) exocytosis. D) endocytosis. E) phagocytosis.
28)
Osmosis can only occur if water travels through the A) cell wall. B) semipermeable membrane. C) vacuole. D) ER. E) cytoskeleton.
29) A type of molecule movement of that is specific and passive and becomes saturated if all of the protein carriers are in use: A) exocytosis. B) facilitated diffusion. C) active transport. D) endocytosis. E) osmosis.
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30) is
A type of molecule movement that is specific and requires carrier molecules and energy
A) exocytosis. B) facilitated diffusion. C) active transport. D) endocytosis. E) osmosis.
31) In a single pump cycle where sodium and potassium are exchanged and ATP is used, the following is expected: A) 3 sodium ions leave and 2 potassium ions enter. B) 2 sodium ion entersand 1 potassium ion leaves. C) 2 sodium ion leavesand 1 potassium ion enters. D) 3 sodium ions enter and 2 potassium ions leave. E) sodium and potassium ions enter and water leaves.
32)
The accumulation of amino acids and sugars within animal cells can occur through: A) ATP pumps. B) sodium-potassium pumps. C) glucose pumps. D) coupled transport. E) proton pumps.
33)
Cholesterol functions in the plasma membrane to
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A) transport ions. B) serve as an energy molecule. C) maintain fluidity. D) mediate steroid action. E) maintain hypertension.
34) A phospholipid molecule has a polar and a nonpolar end. Because of this, water molecules form: A) polar bonds with the nonpolar end of the phospholipid molecule. B) polar bonds with the polar end of the phospholipid molecule. C) hydrogen bonds with the nonpolar end of the phospholipid molecule. D) hydrogen bonds with the polar end of the phospholipid molecule. E) covalent bonds with the nonpolar end of the phospholipid molecule.
35)
The fluid mosaic model proposed by Singer and Nicolson in 1972 explained that
A) the cell membrane was composed of lipids and proteins. B) the cell membrane was composed of a phospholipid bilayer between two layers of globular proteins. C) the cell membrane was composed of a phospholipid bilayer with globular proteins actually inserted into the bilayer. D) the cell membrane was composed of a phospholipid bilayer but the polar ends of the phospholipid molecules were reversed.
36) Membrane proteins serve many functions. One of the functions is transportation of substances across the membrane. If a cell biologist placed cells into an environment in which a chemical has been added that blocks the function of only carrier proteins, the process that will be affected is
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A) activetransport. B) osmosis. C) simplediffusion. D) phagocytosis. E) pinocytosis.
37)
In the process of diffusion, molecules move from areas where
A) their concentration is higher to areas where their concentration is lower until an equilibrium is reached. B) their concentration is lower to areas where their concentration is higher until an equilibrium is reached. C) their concentration is lower to areas where their concentration is higher through specific protein channels or carriers. D) their concentration is higher to areas where their concentration is lower using energy from ATP.
38) Facilitated diffusion is an important method cells use to obtain and remove necessary molecules. Requirements for facilitated diffusion include: A) The carrier molecule must be specific to the molecule that is transported. The direction of movement is always with the concentration gradient, never against the gradient. B) The carrier molecule is nonspecific to the molecule that is transported. The direction of movement is always with the concentration gradient, never against the gradient. C) The carrier molecule is nonspecific to the molecule that is transported. The direction of movement is always against the concentration gradient, never with the gradient. D) The carrier molecule must be specific to the molecule that is transported and an ATP molecule must be attached to the specific carrier. The direction of movement is always against the concentration gradient, never with the gradient.
39) A research laboratory is attempting to collect the content of human red blood cells. The type of solution researchers should use to cause blood cells to lyse (burst) should be:
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A) hyperosmotic. B) isosmotic. C) hypoosmotic. D) osmotic.
40) One day during the summer you and some friends make ice cream using an electric ice cream maker. To get the ice cream to form, a mixture of salt and ice is packed around the ice cream maker. A few days later you notice a yellow circle of dead grass where the ice cream maker had been placed. You hypothesize that some of the salt and ice mixture spilled onto the grass and ___. A) froze the grass B) was isosmotic to the grass cells causing the yellow circle of dead grass C) was hyperosmotic to the grass cells causing the yellow circle of dead grass D) was hypoosmotic to the grass cells causing the yellow circle of dead grass
41)
What is the main component of an animal cell membrane? A) phospholipids B) polynucleotides C) aquaporins D) glycolipids E) cholesterol
42) A scientist performs an experiment in which they create an artificial cell with a selectively permeable membrane through which only water can pass. They inject a 5M solution of glucose into the cell and then place the cell into a beaker of water. After an hour, what effect do you expect to observe?
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A) Water moves out ofthe cell B) Glucose moves outof the cell C) No net change incell weight D) Water moves intothe cell E) Glucose moves intothe cell
43) A scientist performs an experiment in which they create an artificial cell with a selectively permeable membrane through which only water can pass. They inject a 5M solution of glucose into the cell and then place the cell into a beaker containing 10M glucose. What effect do you expect to observe? A) Water moves out ofthe cell B) Glucose moves outof the cell C) No net change incell weight D) Water moves intothe cell E) Glucose moves intothe cell
44)
Turgor pressure is observed when a plant cells environment is ________________. A) hypoosmotic B) isosmotic C) osmosis D) hyperosmotic
45)
What initiates the sodium-potassium pump?
A) Three sodium ions bind to the cytoplasmic side of the protein. B) Three sodium ionsare translocated out of the cell. C) Phosphorylatedpump has low affinity for sodium allowing sodium to leave and potassium tobind. D) Two potassium ions are transported into the cell. E) ATP binds to the protein which becomes phosphorylated (ADP is released).
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46) Cyclodextrins are a group of compounds capable of removing cholesterol from membranes. The effect most likely to have a large impact on cells as a result of cyclodextrin treatment would be A) increasedconcentration of transmembrane proteins. B) increasedpermeability of the membrane. C) increased membranefluidity at lower temperatures. D) increased membranefluidity at higher temperatures. E) disruption oftransmembrane protein structure.
47)
Membrane fluidity is affected by A) temperature,cholesterol, types of fatty acids. B) size of molecules,polarity of molecules, temperature. C) types of fattyacids, waters affinity for hydrogen bonding. D) hyrophillic tails,hydrophobic heads, cholesterol.
48) GABA receptors play an essential role in neurotransmission in the central nervous system. In response to the appropriate signal, these receptors open up and allow Cl- to flow into the cell. Given this information, GABA receptors can be classified as a A) gated ion channel. B) gated carrier protein. C) symporter. D) Cl- pump.
49) Protein X contains four transmembrane domains, a short N-terminus and a long Cterminus. Following protein synthesis, the N-terminus of the protein faces the lumen (the inside) of the ER. After protein X is transported to the cell surface via exocytosis, you would expect the N-terminus of protein X to be
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A) extracellular. B) cytoplasmic. C) in the lumen. D) in the lipid bilayer of the plasma membrane.
50) Incubation of cells at 20°C blocks the release of proteins from the trans-Golgi. Under such conditions, you would expect to see A) an increase in exocytosis. B) a decrease in exocytosis. C) an increase in endocytosis. D) a decrease in endocytosis.
51) While eating lobster for dinner one night your friend asks what you think might happen if this marine invertebrate, which is normally isosmotic with respect to the surrounding seawater, were to be moved to a bay with a slightly lower salt concentration instead of being caught. You reply that, in order for the lobster to be isosmotic with respect to new environment, A) it must move water in to match the solute concentration of its new environment. B) it regulates its internal concentration of solutes to match that of its new environment. C) it must move water out to match the solute concentration of its new environment. D) it moves water inor out and regulates its internal concentration of water as needed.
52) If a cell has a normal osmotic pressure of 4500 mmHg and is placed into a solution with an osmotic pressure of 3500 mmHg, what will happen to the cell? A) The cell will lose water and its osmotic pressure will decrease. B) The cell will gain water and its osmotic pressure will decrease. C) The cell will gain water and its osmotic pressure will increase. D) The cell will lose water and its osmotic pressure will increase.
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53) In individuals with normal blood sugar levels, glucose is reabsorbed into the bloodstream in the kidney by members of the GLUT transporter family, which form an aqueous pore across the membrane through which glucose can move passively. As a result, no glucose is excreted in urine. However, in people with untreated diabetes mellitus, blood sugar levels are high and glucose is often present in the urine. What can explain this occurrence? A) High blood glucose levels reverse the concentration gradient, allowing untransported glucose to be excreted in urine. B) High blood glucose levels interfere with the coupled transport of water and glucose, allowing untransported glucose to be excreted in urine. C) The GLUT transporters become saturated, allowing untransported glucose to be excreted in urine. D) The GLUT transporters cannot hydrolyze ATP quickly enough for ATP to transport the extra glucose, thereby allowing untransported glucose to be excreted in urine.
54) Which mutations can interfere with the proper insertion of a protein in the plasma membrane? A) A polar amino acid to a nonpolar amino acid within a transmembrane domain B) A nonpolar amino acid to a polar amino acid within a transmembrane domain C) A polar amino acid to a nonpolar amino acid within a cytoplasmic domain D) A nonpolar amino acid to a polar amino acid within a cytoplasmic domain
55) During neuronal signaling, a change in membrane potential will cause sodium channels to open and let Na+ ions diffuse down their concentration gradient into the cell. Which of the following helps establish the concentration gradient necessary for this process to occur? A) Na+/K+ channel B) voltage-gated Na+ channel C) Na+ symporter D) Na+/K+ pump
56) If you were to replace the phosphate group of a phospholipid with a fatty acid chain, you would have Version 1
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A) glycerol. B) a triglyceride. C) cholesterol. D) glycolipid.
57) If you were a very thirsty cell, which process would you use to take in some nutrients secreted by one of your neighbors? A) Phagocytosis B) Pinocytosis C) Receptor-mediatedendocytosis D) Exocytosis
58)
How can freeze-fracture be used to determine the orientation of a protein in a membrane?
A) Freeze-fracture allows a cell to be cleaved in between the lipid bilayer, splitting the plasma membrane into two layers. B) Freeze-fracture allows a cell to be cleaved in such a way as to preserve the embedded proteins. C) Freeze-fracture cuts the membrane in protein-sized components for viewing under an electron microscope.
59) Diapedesis is the movement of white blood cells through intact blood vessel walls into surrounding body tissue. It typically happens when an area of the body is injured or damaged, and an inflammation response is required. What role would you expect cell adhesion molecules to play in this process?
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A) Cell adhesion molecules will allow the white blood cells to cling to one another to form a migrating clot. B) Cell adhesion molecules help white blood cells adhere to the blood vessel wall so that they can migrate across the wall and infiltrate into the underlying tissue. C) Cell adhesionmolecules will allow the white blood cells to attach to the injured area sothey become immobile.
60)
Membrane potential will affect the directional movement of A) Glucose(C6H12O6) B) Cholesterol C) Potassium(K+) D) Oxygen(O2)
61)
The rate of diffusion of molecules would be fastest in a cell with an
A) internalconcentration of 45 percent and an external concentration of 50 percent incold temperatures. B) internalconcentration of 50 percent and an external concentration of 12 percent in coldtemperatures. C) internalconcentration of 50 percent and an external concentration of 12 percent in warmtemperatures. D) internalconcentration of 40 percent and an external concentration of 35 percent in warmtemperatures.
62) When the solute concentration of solution A is lower than the solute concentration of solution B, solution A is considered A) hypertonic. B) hypotonic. C) isotonic.
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63) Tetrodotoxin is a potent poison, produced by some newts, pufferfish, and blue-ringed octopus that affects sodium transport involved with the voltage gates in neurons. A friend swimming in the Caribbean is pricked by a pufferfish and gets very sick. The most likely action the poison takes is A) Mimicking asymporter and allowing sodium to rush out and potassium to rush in. B) Mimicking anantiporter and allowing sodium to rush out. C) Blocking anantiporter so sodium cannot rush in. D) Blocking asymporter and keeping sodium from rushing in.
64) An individual is constipated. They take magnesium salts to help loosen the stool. Why does this work? A) Water moves fromthe intestines to the blood because the blood is hypertonic B) Water moves fromthe intestines to the blood because the blood is hypotonic. C) Water moves fromthe blood to the intestines because the blood is hypertonic D) Water moves fromthe blood to the intestines because the blood is hypotonic.
65)
A dehydrated runner drinks a lot of water after a race. He or she rehydrates because A) the contents of the digestive tract are hypotonic compared to the bloodstream. B) the bloodstream is hypotonic compared to the contents of the digestive tract. C) the contents of the digestive tract and the bloodstream are isotonic compared to each
other. D) water will diffuse from an area where its concentration is low to an area where its concentration is high.
66) To test for the presence of starch, iodine can be used. A positive reaction results in a black color. A dialysis (semi-permeable) bag filled with starch solution and secured on both ends is placed in iodine solution. After 30 minutes the dialysis bag appears black. Based on this information, what most accurately describes what happened?
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A) Due to its sizeand polarity, starch was able to exit the dialysis bag and interact with theiodine solution. B) Due to its sizeand polarity, iodine was able to enter the dialysis bag and interact withstarch. C) Over time, both iodine and starch are equally distributed throughout the twosolutions.
67) A mixed solution of water and small molecules is exposed to a cell membrane and allowed to interact for an hour. Which molecule would be most likely to cross the phospholipid bilayer without the aid of transport proteins and diffuse across the membrane the fastest? A) Estrogen (C18H24O2) B) NH4+ C) O2 D) CH3COOE) Na+
68)
If Na+ levels were depleted in the extracellular fluid, rate of glucose movement would A) increase. B) decrease. C) stay the same.
69) A novice gardener notices that many plants in his garden look wilted. What osmotic solution would you suggest the novice gardener use to best return the plants to full health? A) Place the plantsin a 15% solute solution so water can be actively transported out of the plantcells. B) Place the plantsin a 5% solute solution so water can be actively transported out of the plantcells. C) Place the plantsin a 5% solute solution so water can diffuse into the plant cells. D) Place the plantsin a 15% solute solution so water can diffuse out of the plant cells.
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70) Kwame is studying how the protein transferrin enters cells. He examines cells that have taken up transferrin, and finds clathrin-coated vesicles. What mechanism was used to take transferrin into the cell? A) Phagocytosis B) Pinocytosis C) Exocytosis D) Receptor-mediatorendocytosis
SECTION BREAK. Answer all the part questions. 71) Three (3) eggs are boiled and all weigh 2g. The eggs are placed in a 15% solution of NaCl and reweighed after 30 minutes.
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71.1)
The solution in the container is hypertonic to which egg?
A) Egg 1 B) Egg 2 C) Egg 3
71.2)
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A) Egg 1 B) Egg 2 C) Egg 3
71.3)
When compared to the solution, the egg that gained weight was ______.
A) Hypertonic B) Hypotonic C) Isotonic
72) The diagram shows the rate of diffusion into a cell using carrier proteins.
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72.1)
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Carrier proteins are saturated at which point?
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A) 1 B) 2 C) 3 D) 4
72.2)
The rate of diffusion will increase as
A) the number ofglucose molecules decreases. B) the number ofglucose molecules increases. C) temperaturedecreases. D) pH rises.
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Answer Key Test name: Chap 05_13e_Raven 1) [A, B, C, E] Examples of phagocytosis and pinocytosis are correct. The only incorrect answer is directing synthesis, which is the job of the nucleus. 2) [B, C, E]
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Clarify Question • What is the key concept addressed by the question? o The question asks about receptor-mediated endocytosis. • What type of thinking is required? o You are being asked to apply your knowledge about receptormediated endocytosis. Gather Content • What do you know about receptor-mediated endocytosis? What other information is related to the question? o Molecules are often transported into eukaryotic cells through receptor-mediated endocytosis. These molecules first bind to specific receptors in the plasma membrane—they have a conformation that fits snugly into the receptor. The portion of the receptor molecule that lies inside the membrane is trapped in an indented pit coated on the cytoplasmic side with the protein clathrin. Each pit acts like a molecular mousetrap, closing over to form an internal vesicle when the right molecule enters the pit. Large molecules like low density lipoprotein that carry cholesterol through the blood are taken up by this process. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Receptor-mediated endocytosis is an active process in which clatherin coated pits bring in molecules bound to receptors on the surface of the cell. Cholesterol is taken into cells by this process. It is not passive diffusion of molecules through carrier proteins in the membrane. Reflect on Process Version 1
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about receptormediated endocytosis. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that clathrin coated pits were involved? Did you think the process involved passive diffusion through a carrier protein? 3) [B, C, D]
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Clarify Question • What is the key concept addressed by the question? o The question asks about concentration gradients. • What type of thinking is required? o You are being asked to apply your knowledge about concentration gradients. Gather Content • What do you know about concentration gradients? What other information is related to the question? o Concentration gradients are formed when the concentration of a molecule is different on two sides of a membrane. Concentration can be measured by mass per volume, percentage or partial pressure for gasses. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Temperature is not a unit of concentration. The other examples all show a difference in concentration across a membrane in either percentage, glucose concentration, or partial pressure of CO2 gas. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about concentration gradients. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that Version 1
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temperature was a measure of concentration? Did you think that pCO2 was not a concentration? 4) [D, E]
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Clarify Question • What is the key concept addressed by the question? o The question asks about forms of transport that require ATP. • What type of thinking is required? o You are being asked to apply your knowledge about forms of transport that require ATP. Gather Content • What do you know about forms of transport that require ATP? What other information is related to the question? o Movement down a concentration gradient is a passive process and does not require ATP. These include osmosis, diffusion and facilitated diffusion. Active transport uses ATP to move molecules against their concentration gradient. Endocytosis requires ATP to pinch the membrane forming a vesicle inside of the cell. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Active transport and endocytosis require ATP, so if ATP formation is blocked they will cease. The other forms of transport do not require ATP as molecules move down their concentration gradient. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about forms of Version 1
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transport that require ATP. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that movement down a concentration gradient requires ATP? Did you realize that endocytosis requires ATP? 5) [A, B, D, G]
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Clarify Question • What is the key concept addressed by the question? o The question asks about coupled transport of glucose and sodium. • What type of thinking is required? o You are being asked to analyze statements about coupled transport of glucose and sodium. Gather Content • What do you know about coupled transport of glucose and sodium? What other information is related to the question? o The active glucose transporter uses the Na+ gradient produced by the Na+/K+ pump as a source of energy to power the movement of glucose into the cell. In this system, both glucose and Na+ bind to the transport protein, which allows Na+ to pass into the cell down its concentration gradient, capturing the energy and using it to move glucose into the cell through a symporter. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Na+ moves down its concentration gradient, moving glucose against its concentration gradient through coupled transport. The movement of Na+ ions down its gradient is a form of energy, so glucose is being moved by a form of active transport. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? o This question asked you to analyze statements about coupled transport of glucose and sodium. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that sodium and glucose were transported by an antiporter? Did you think that glucose transport was not linked to Na+ transport? 6) [A, C, D]
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Clarify Question • What is the key concept addressed by the question? o The question asks about glucose transport. • What type of thinking is required? o You are being asked to analyze statements about glucose transport. Gather Content • What do you know about glucose transport? What other information is related to the question? o Passive transport of glucose indicates that glucose is moving down its concentration gradient through the GLUT transporter. This means that it does not require ATP or cotransport of water. The GLUT transporter is a protein that makes a pore through the membrane of cells allowing glucose to enter. The number of glucose transporters on the surface of the cell is controlled in part by insulin. Insulin binds to receptors on the surface of the cell and causes more transporters to be present on the cell, increasing the rate of glucose diffusion into the cell. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o As insulin increases, more GLUT transporters appear on the surface of the cell, increasing the rate of glucose diffusion into the cell. If insulin levels or the number of insulin receptors drop there will be no increase in GLUT transporters on the surface of the cell and glucose uptake will decrease. Reflect on Process
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze statements about glucose transport. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that ATP was necessary for glucose diffusion into a cell? Did you think that the insulin receptor was not needed for glucose uptake? 7) A Phospholipids make up the majority of the cell membrane, with (transmembrane) proteins allowing solutes to be transported though this semipermiable barrier, and cholesterol leading to its flexibility. Carbohydrates can be found on the surface of cells and can function as signaling molecules, but all three of these subtypes only play a supporting role to the phospholipids, who form the majority of the structure, with the fatty acid tails being the hydrophobic center and the hydrophilic phosphate heads facing both the inside and outside of the cell in this unique bilayer. 8) B The proteins and phospholipds move around within the lipid bilayer, but the bilayer does not separate 9) D Bulk transport usually refers to vesicles, active transport moves up the concentration gradient, and saturation refers to concentration, not movement 10) A None of the other choices move across a cell membrane 11) A Version 1
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Cytoskeletal proteins support the cell shape, as do structural proteins. "Targeted" proteins is a broad term. 12) D Only aquaporins specifies osmosis movement 13) A The rest of these choices are not located in the lipid bilayer 14) B All choices can be found in transmembrane proteins, the only choice that would make a protein non-water soluble would be hydrophobic properties 15) A Hydrophobic and hydrophilic refer to the chemical relationship with water. Hypertonic and hypotonic are when the concentrations are different between the cell and the environment. 16) D Osmosis and diffusion do not rely on external energy sources. Facilitated diffusion (transport) is a passive event. Exocytosis does rely on energy, but does not move based on concentration gradient or proteins. 17) C The hydrophobic tails are oriented away from the water in the environment, so they are shielded in the center. The hydrophilic heads then face the inside and outside of the cell, since they can interact with water. 18) B The phospholipids are not bound to each other so they are free to move around and allow proteins to move between them
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19) D Carbohydrates are often used as cell markers. The other choices are smaller, free floating molecules that would be used for other purposes by the cell. 20) B Hormones bind to receptor proteins, but they are not attached permanently to the cell surface. 21) C Only one of these options allows the amino acids to interact with the highly non-polar, hydrophobic tails. 22) C The function of spectrins is to determine the shape of the cell. 23) B When a solute moves from high concentration to low concentration, it does not need energy. Movement without using energy is not active, and only one choice here does not need an energy source such as ATP 24) C Remember that "iso" means same, "hypo" means less, and "hyper" means more. Also recall that osmosis only relates to the movement of water molecules, not solute. 25) D A cell wall is designed to withstand this high pressure. 26) C Active transport, diffusion, and osmosis take place on an molecular level. The term "pinocytosis" means "cell drinking" and not cell eating. 27) A Version 1
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All other choices require energy and go against the concentration gradient. 28) B Water should not be able to travel though any of the other structures mentioned freely, with the excpetion of the semipermeable membrane 29) B Facilitated diffusion allows movement of specific molecules though transport proteins without the use of energy (ATP). 30) C Active transport requires carrier, transmembrane proteins that use energy (usually ATP) 31) A Na+ is kicked out of the cell, and K+ is drawn in. More Na+ is removed (3 ions) than K+ (2 ions) is brought in, leading to a net negative change in the cell. 32) D Coupled transport links the movement of two molecules, and uses the energy of diffusion of one molecule to help drive the reaction. Additional ATP is also required. 33) C Cholesterol is used to maintain the 'sticky' or 'squishy' nature of the plasma membrane. 34) D
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Water molecules can form hydrogen bonds with other molecules due to their dipolar charge, and are attracted to polar molecules due to the ability of the water to interact with them. A phospholipid molecule has a polar head and a non-polar tail, so water is only attracted to one side of the molecule. 35) C It was unique and important to realize that the proteins were inserted into the lipid bilayer and interacting with the phospholipids to stay in place. 36) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about carrier proteins. • What type of thinking is required? o You are being asked to apply your knowledge of carrier proteins to predict which process will be affected if they are inhibited. • What key words does the question contain and what do they mean? o Carrier proteins – these channels use ATP to move molecules across a membrane. Gather Content • What do you know about transport of molecules across membranes? How does it relate to the question? o Molecules that can move directly through a membrane do so by simple diffusion, or osmosis in the case of water. o Large macromolecules or fluids enter cells through phagocytosis or pinocytosis in which vesicles bud off of the plasma membrane, bringing the molecules into the cell. Consider Possibilities • What other information is related to the question? Which information is most useful? o Only carrier proteins are being affected and the molecules are being transported across the membrane. This means that processes like phagocytosis or pinocytosis that use vesicles would not be affected. Choose Answer • Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer? o Osmosis and diffusion do not require proteins. Carrier proteins use ATP to move molecules across the membrane by active transport. Therefore, inhibiting carrier proteins will inhibit active transport. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of how molecules move across membranes to predict what process would be inhibited if the activity of carrier proteins was blocked. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that carrier proteins are used to move molecules across membranes in active transport? Did you understand that molecules capable of osmosis or simple diffusion do not require proteins to move across membranes? Did you recall that pinocytosis and phagocytosis move molecules across membranes by forming vesicles? 37) A 38) A Facilitated diffusion is the same as diffusion, but is more closely controlled using membrane proteins that allow a specific molecule to cross. 39) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about osmotic concentration. • What type of thinking is required? o You are being asked to apply your knowledge of osmotic concentration to choose what solution would cause a red blood cell to lyse. • What key words does the question contain and what do they mean? o Type of solution – the question is specifically asking about the osmotic concentration of the solution. o Cell lysis – this requires enough water to enter the cell to cause it to swell until it bursts. Gather Content • What do you know about osmotic concentration? How does it relate to the question? o Hyperosmotic solutions would contain more salt than the cells, hyper is the root for more. o Hypoosmotic solutions would contain less salt than the cells, hypo is the root for less. o Isoosmotic solutions would contain the same salt concentration as the cells, iso is the root for same. Consider Possibilities • What other information is related to the question? Which information is most useful? o Water moves across membranes by osmosis. Water will move from an area of lower salt concentration to an area of higher salt concentration until the salt concentration on both sides is equal. Version 1
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If you want red blood cells to swell, you want water to move into the blood cells. For this to happen the cells need to have more salt inside them than the surrounding solution. The solution would then be hypo osmotic relative to the cells, and contain less salt than the cells. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the definition of osmotic concentration to determine what type of solution would cause a red blood cell to lyse. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that for a cell to swell up it would need to be in a solution with a lower salt concentration than the inside of the cell? Did you remember what the roots hyper, hypo and iso mean? Did you understand that in osmosis water moves from an area of lower salt to higher salt? 40) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about osmotic concentration. • What type of thinking is required? o You are being asked to analyze an observation and explain what happened to grass exposed to salt. • What key words does the question contain and what do they mean? o Ice and salt – when making ice cream, salt is mixed with ice to make a super cooled solution that help the ice cream form. o Yellow circle of dead grass – this shows that where the salt and ice mixture came into contact with the grass, the grass was killed. Gather Content • What do you know about osmotic concentration? How does it relate to the question? o Plants are normally hyperosmotic to the water in the ground. This causes water to move into the plant cells through osmosis. When salt water comes into contact with the grass this process is reversed and water moves from the inside of the plant (lower salt concentration) to the ground (now with a higher salt concentration). Consider Possibilities • What other information is related to the question? Which information is most useful? o Hyperosmotic solutions would contain more salt than the cells, hyper is the root for more. o Hypoosmotic solutions would contain less salt than the cells, hypo is the root for less. o Isoosmotic solutions would contain the same salt concentration as the Version 1
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cells, iso is the root for same. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The salt and ice mixture has a higher concentration of salt than the grass cells, so it is hyperosmotic. The higher salt concentration pulls water from the grass, causing it to die. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze the observation that a salt and ice mixture caused grass to die and propose an explanation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize that it was the salt in the salt and ice mixture that was killing the grass? Did you understand that the ice and salt mixture was hyperosmotic relative to the grass cells? 41) A Phospholipids make up the bulk of the plasma membrane, and cholesterol makes up only a small percentage of it. Polynucleotides mean DNA and are not found in this location. The remaining two choices are only present in a small amount. 42) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about osmotic concentration. • What type of thinking is required? o You are being asked to apply your understanding of osmotic concentration to predict what will happen to a cell if it is injected with 5M glucose. • What key words does the question contain and what do they mean? o Selectively permeable membrane – this is a membrane that keeps polar and charged molecules from crossing it, but will allow water and gasses to diffuse through the membrane. o 5M glucose – M is molar or moles per liter. A 5M solution of glucose is very high, for example soda is 0.5M glucose. Glucose is a polar molecule and will not be able to cross the membrane. The cell will have a higher osmotic concentration now and will be hyper osmotic relative to the water. Gather Content • What do you know about osmotic concentration? How does it relate to the question? o Increasing the amount of glucose in the synthetic cell will increase its osmotic concentration. Consider Possibilities • What other information is related to the question? Which information is most useful? o With an increased osmotic concentration of glucose inside of the cell, the cell will be hyper osmotic and the water hypoosmotic. Water moves from areas of lower osmotic concentration to higher osmotic Version 1
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concentration until the osmotic concentrations on both sides of the membrane are the same. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Since the osmotic concentration on the inside of the cell is higher with the 5M glucose added, the water will move into the cell by osmosis. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of osmotic concentration to predict the direction water will move when a cell is made hyper osmotic to its surroundings. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you understand what would happen to the osmotic concentration inside the cell when it was injected with 5M glucose? Did you recall that water will move from an area of lower to higher osmotic concentration? Did you recall that a semipermeable membrane will not allow polar molecules like glucose to cross while water can cross the membrane? 43) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about osmotic concentration. • What type of thinking is required? o You are being asked to apply your understanding of osmotic concentration to predict what will happen to a cell if it is injected with 5M glucose and then placed into a solution that is 10M glucose. • What key words does the question contain and what do they mean? o Selectively permeable membrane – this is a membrane that keeps polar and charged molecules from crossing it, but will allow water and gasses to diffuse through the membrane. o 5M glucose – M is molar or moles per liter. A 5M solution of glucose is very high, for example soda is 0.5M glucose. Glucose is a polar molecule and will not be able to cross the membrane. Gather Content • What do you know about osmotic concentration? How does it relate to the question? o Increasing the amount of glucose in the synthetic cell to 5M will increase its osmotic concentration relative to water. o When the cell is placed into a 10M solution, the cell will have a lower osmotic concentration relative to the 10M solution. Consider Possibilities • What other information is related to the question? Which information is most useful? o With a decreased osmotic concentration of glucose inside of the cell, the cell will be hypoosmotic and the 10M solution hyper osmotic. Water moves from areas of lower osmotic concentration to higher osmotic Version 1
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concentration until the osmotic concentrations on both sides of the membrane are the same. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Since the osmotic concentration on the inside of the cell (5M) is lower than the solution (10M), the water will move out of the cell by osmosis. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of osmotic concentration to predict the direction water will move when a cell is made hypoosmotic to its surroundings. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you understand what would happen to the osmotic concentration inside the cell when it was injected with 5M glucose? Did you recall that water will move from an area of lower to higher osmotic concentration? Did you recall that a semipermeable membrane will not allow polar molecules like glucose to cross while water can cross the membrane? 44) A Turgor is seen when a plant is 'stiff,' or not limp. In order for this to occur, the plant cell should be filled with the maximum amount of water possible. If the environment is hypotonic, water will always want to enter the cell via osmosis, but the plant cell is prevented from bursting via the strong cell wall. Version 1
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45) A Binding Na+ ions is the first step of this process. 46) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about the role of cholesterol in a membrane. • What type of thinking is required? o You are being asked to apply your knowledge of the role of cholesterol in a membrane to predict what would happen if it were removed. • What key words does the question contain and what do they mean? o Cholesterol in membranes – typically cholesterol increases the fluidity of membranes by preventing the fatty acid tails of phospholipids from clustering together as tightly. Gather Content • What do you know about the role of cholesterol in membranes? How does it relate to the question? o Biological membranes are typically comprised of mostly phospholipids. Cholesterol in a membrane will prevent the fatty acid tails of the phospholipids from packing together very tightly. This keeps the membrane more fluid. Consider Possibilities • What other information is related to the question? Which information is most useful? o The drug cyclodextrin removes cholesterol from the membrane. Because cholesterol makes the membrane fluid, removal of cholesterol could make the membrane less fluid. Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The best answer is that removal of cholesterol would decrease membrane fluidity. o Decreased membrane fluidity should not affect the abundance or activity of membrane proteins. o Decreased membrane fluidity would also decrease permeability and osmosis rather than increase the activities. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of the role of cholesterol in a membrane to predict what would happen if it was removed. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that cholesterol increases membrane fluidity? Could you predict then that removal of cholesterol would decrease membrane fluidity? Did you understand that decreased fluidity would decrease permeability or osmosis and not increase these activities? 47) A The plasma membrane is a complex interaction in which like attracts like, so hydrophilic heads and hydrophobic tails bind together to create a bilayer. Cholesterol allows the phospholipids some fluidity in their interactions. 48) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about the transport of molecules across a membrane. • What type of thinking is required? o You are being asked to apply your knowledge of transport proteins to explain how Cl- ions cross a membrane. • What key words does the question contain and what do they mean? o GABA receptors – these are proteins in a membrane that bind to aligand, in this case the neurotransmitter GABA. o Open up and allow Cl- into a cell – the GABA receptors are normally closed and when the open Cl- can cross the membrane. o Cl- - this is a chloride ion with a negative charge. Gather Content • What do you know about protein transporters? How does it relate to the question? o Charged and polar molecules cannot cross a membrane without the assistance of a protein channel. GABA receptors can bind aligand (GABA) and then open up a channel that allows Cl- ions to move through. In this way the GABA receptor is acting as a gate that can open to allow ions to flow through, down their concentration gradient. Consider Possibilities • What other information is related to the question? Which information is most useful? o Symporters open channels that allow two molecules to enter a cell simultaneously. One of the molecules is flowing down its concentration gradient and that energy is used to move the second molecule against its Version 1
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concentration gradient. In the case of the GABA receptor, no mention is made of a second molecule moving through the channel. o A pump is a protein that uses ATP or another energy source to drive active transport of a molecule against its concentration gradient. No mention is made of ATP being used in the case of the GABA receptor. o A gated carrier protein binds directly to the molecule it assists, and allows it to cross the barrier by physically changing shape. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The best answer is that the GABA receptor is a gated ion channel. When it is closed, no ions can move across the channel. When GABA binds to the receptor, the channel opens and the Cl- ion can move down its concentration gradient and enter the neuron. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the definition of a gated ion channel to a specific example. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you understand that Cl- was an ion? Did you recognize that the GABA receptor was acting as a gate, preventing Cl- ions from crossing the membrane until GABA bound to the receptor? Did you observe that no mention was made of ATP or another molecule moving across the membrane? 49) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about the orientation of a protein in a membrane. • What type of thinking is required? o You are being asked to apply your knowledge of how proteins are oriented in a membrane and the process of exocytosis. Gather Content • What do you know about how proteins are oriented in a membrane? What other information is related to the question? o When a protein is made in the endoplasmic reticulum, the part facing the inside is said to be in the lumen. Proteins move from the endoplasmic reticulum to the plasma membrane through small lipid vesicles that pinch off the endoplasmic reticulum. Proteins facing the lumen will remain on the inside of these vesicles. When the vesicles fuse with the plasma membrane it is like a bubble popping and the contents inside the vesicle will now be outside of the cell. Similarly the proteins in the membrane will now be facing outside of the cell. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Proteins on the inside or lumen of the endoplasmic reticulum will be on the extracellular or outside of the membrane after being transported through vesicles. Reflect on Process • Did your problem-solving process lead you to the correct answer? Version 1
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If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge of how proteins are oriented in a membrane. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that proteins on the inside of a vesicle remained on the inside of a cell when it fused with the plasma membrane? Did you think that the protein would be buried in the lipid bilayer? 50) B 51) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about adaptation to a change in the salinity. • What type of thinking is required? o You are being asked to apply your knowledge about adaptation to a change in the salinity. Gather Content • What do you know about adaptation to a change in the salinity? What other information is related to the question? o Some organisms that live in the ocean adjust their internal concentration of solutes to match that of the surrounding seawater. Because they are isosmotic with respect to their environment, no net flow of water occurs into or out of these cells. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If the lobster allowed a lot of water to enter its body to keep the salt concentration equal to that of the surrounding water it would become swollen. Instead it adjusts its internal concentration of salts to maintain water balance. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about adaptation to Version 1
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a change in the salinity. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think the lobster would take in large amounts of water to maintain salt balance?Did you think that the lobster could secrete water from its body? 52) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about how a cell responds to differences in osmotic pressure. • What type of thinking is required? o You are being asked to apply your knowledge about how a cell responds to differences in osmotic pressure. Gather Content • What do you know about how a cell responds to differences in osmotic pressure? What other information is related to the question? o Water tends to move from an area of lower osmotic pressure to an area of higher osmotic pressure until there is an equilibrium between the two solutions. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If the inside of the cell has an osmotic pressure of 4500 mmHg and the surrounding fluid has an osmotic pressure of 3500 mmHg, the surrounding fluid is hypotonic with respect to the cell, and water will tend to enter the cell. As water enters the cell, the osmotic pressure inside the cell would decrease. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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o This question asked you to apply your knowledge about how a cell responds to differences in osmotic pressure. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that water moves from an area of lower osmotic pressure to an area of higher osmotic pressure? Did you understand that a cell gaining water would experience a decrease in osmotic pressure? 53) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about glucose movement through the GLUT transporter. • What type of thinking is required? o You are being asked to apply your knowledge about glucose movement through the GLUT transporter. Gather Content • What do you know about glucose movement through the GLUT transporter? What other information is related to the question? o Passive transport of glucose indicates that glucose is moving down its concentration gradient through the GLUT transporter. This means that it does not require ATP or cotransport of water. The GLUT transporter is a protein that makes a pore through the membrane of kidney cells. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Because the GLUT transporter forms a pore of a given size, only so many glucose molecules can move through it at a time. In diabetes blood glucose levels increase dramatically. So if glucose levels increase, not all of the glucose molecules may be reabsorbed in time and some will be secreted in the urine. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about glucose movement through the GLUT transporter. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that passive movement of glucose through the GLUT transporter required ATP? Did you think that elevating the glucose level would reverse the glucose concentration gradient? 54) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the amino acids found in a transmembrane domain. • What type of thinking is required? o You are being asked to apply your knowledge about the amino acids found in a transmembrane domain. Gather Content • What do you know about the amino acids found in a transmembrane domain? What other information is related to the question? o Transmembrane domains contain nonpolar amino acids because the membrane itself is nonpolar. Polar amino acids are found more on the cytoplasmic portions of a protein that interact with water. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If a nonpolar amino acid was changed to a polar amino acid in a transmembrane domain it would interfere with the insertion of a protein into a membrane. Changes in the cytoplasmic domain would not affect this process and nonpolar amino acids will interact better than the polar amino acids with the membrane. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about the amino acids found in a transmembrane domain. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that polar amino acids would be found on a membrane? Did you think that the inside of a membrane was polar? 55) D 56) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the structure of a phospholipid. • What type of thinking is required? o You are being asked to apply your knowledge about the structure of a phospholipid. Gather Content • What do you know about the structure of a phospholipid? What other information is related to the question? o Phospholipids contain two fatty acid chains attached to a glycerol backbone. There is also a phosphate attached to the glycerol. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If the phosphate was replaced with a fatty acid chain then the glycerol would have three fatty acids attached to it, forming a triglyceride. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about the structure of a phospholipid. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that phospholipids have two fatty acid chains? Did you recall that triglycerides have three fatty acid chains attached to a glycerol Version 1
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backbone? 57) B 58) A 59) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the role of adhesion molecules in white blood cell movement. • What type of thinking is required? o You are being asked to apply your knowledge about the role of adhesion molecules in white blood cell movement. Gather Content • What do you know about the role of adhesion molecules in white blood cell movement? What other information is related to the question? o Adhesion molecules allow two cells to attach to each other. In some tissues, these are very stable long term attachments. Blood cells need to be able to move, so adhesion molecule attachments are short term for these cells Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o By binding to adhesion molecules on cells lining the blood vessels, white blood cells can crawl out of the blood vessel and into the surrounding tissues.. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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o This question asked you to apply your knowledge about the role of adhesion molecules in white blood cell movement. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that white blood cells binding to a region of damage would be immobile? Did you think that white blood cells would bind to each other in the blood stream? 60) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about the impact of membrane potential on the movement of molecules. • What type of thinking is required? o You are being asked to analyze statements about the impact of membrane potential on the movement of molecules. Gather Content • What do you know about the impact of membrane potential on the movement of molecules? What other information is related to the question? o Membrane potentials are formed when there are differences in charge across a membrane. This will affect the movement of charged ions across the membrane with positively charged ions moving toward the side of the membrane with a net negative charge and negatively charged ions moving toward the net positively charged side. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Of the options, only potassium is an ion and will be affected by a membrane potential, moving toward the negatively charged side of the membrane. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? o This question asked you to analyze statements about the impact of membrane potential on the movement of molecules. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize that a membrane potential involved different charges across a membrane? Did you think that molecules without a charge would be affected by the membrane potential? 61) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about factors that affect the rate of diffusion. • What type of thinking is required? o You are being asked to apply your knowledge about factors that affect the rate of diffusion. Gather Content • What do you know about factors that affect the rate of diffusion? What other information is related to the question? o Diffusion relies on the rapid movement of molecules. This occurs most rapidly in warmer temperatures when the molecules are moving faster. The greater the difference in concentration across a membrane, the larger the gradient and the faster molecules will diffuse. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The answer in which the internal concentration of 50 percent and an external concentration of 12 percent in warm temperatures would have the fastest diffusion. The warm temperatures and large gradient would both make diffusion faster in these conditions. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about factors that Version 1
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affect the rate of diffusion. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that molecules diffuse most rapidly in the cold? Did you think that molecules diffuse most rapidly down smaller gradients? 62) B 63) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about the effects of tetrodotoxin on ion movement in neurons. • What type of thinking is required? o You are being asked to evaluate statements about the effects of tetrodotoxin on ion movement in neurons. Gather Content • What do you know about the effects of tetrodotoxin on ion movement in neurons? What other information is related to the question? o When a neuron fires, sodium ions enter the neuron and potassium ions leave the neuron. Both move in opposite direction through an antiporter. Tetrodotoxin blocks sodium entry into the neuron causing paralysis. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Because tetrodotoxin blocks sodium from entering the cell it is acting on an antiporter. If it mimicked a symporter or antiporter then it would stimulate sodium ion transport. If sodium and potassium both entered a cell then the transporter would by a symporter. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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o This question asked you to evaluate statements about the effects of tetrodotoxin on ion movement in neurons. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that sodium and potassium both entered the cell through a symporter? Did you think that tetrodotoxin stimulated sodium ion transport? 64) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about osmosis. • What type of thinking is required? o You are being asked to apply your knowledge about osmosis. Gather Content • What do you know about osmosis? What other information is related to the question? o Osmosis occurs when water moves from a hypotonic region to a hypertonic region. When a person has constipation, they want more water to move from the blood into the intestines. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o By eating magnesium, they increase the concentration of salt in the intestines, making it more hypertonic. As a result water moves from the blood into the intestines. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about osmosis. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that water moved towards a hypotonic solution? Did you think that to relieve constipation Version 1
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you wanted water to move out of the intestines? 65) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about osmosis. • What type of thinking is required? o You are being asked to apply your knowledge about osmosis. Gather Content • What do you know about osmosis? What other information is related to the question? o In osmosis, water moves from an area that is hypotonic to an area that is hypertonic. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o After a race if a person is dehydrated, then there is less water in their blood, and the solute concentration of the blood increases. The water the runner just drank will decrease the solute concentration in the contents of the digestive tract, making the contents hypotonic compared to the bloodstream. The water will then move from the hypotonic digestive tract to the hypertonic blood. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about osmosis. If you got the correct answer, great job! If you got an incorrect answer, Version 1
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where did the process break down? Did you think that water moved toward a hypotonic area? Did you think that drinking water would make the contents of the digestive tract more hypertonic? 66) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about dialysis. • What type of thinking is required? o You are being asked to analyze statements about dialysis. Gather Content • What do you know about dialysis? What other information is related to the question? o In dialysis small molecules can pass through tiny gaps in the membrane. Larger molecules and cells cannot cross the membrane. Starch is a large polymer made up of multiple glucose molecules and cannot diffuse across a dialysis membrane. Iodine is a small ion that can easily diffuse across the dialysis membrane. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o For the iodine to react with the starch, one of the molecules must diffuse across the dialysis membrane. Iodine is much smaller and could do this while starch is very large and could not. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze statements about dialysis. If you got the correct answer, great job! If you got an incorrect answer, where Version 1
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did the process break down? Did you think that starch was a small molecule and could diffuse across the dialysis membrane? Did you think that iodine was a large molecule and could not diffuse across the dialysis membrane? 67) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about diffusion. • What type of thinking is required? o You are being asked to apply your knowledge about diffusion. Gather Content • What do you know about diffusion? What other information is related to the question? o Diffusion occurs when a molecule can move down its concentration gradient. Gases and many nonpolar molecules, including steroid hormones, can diffuse directly across the plasma membrane. However, the plasma membrane has limited permeability to ions, small polar molecules, and especially large polar molecules. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o O2 is oxygen gas and can diffuse directly across a membrane. Estrogen (C18H24O2), a steroid hormone, can also diffuse directly across the membrane because it is nonpolar; however, it is larger than oxygen gas and so wouldn't diffuse as rapidly as oxygen. The other three choices are all ions and polar molecules and would not diffuse rapidly without the aid of transport proteins. Reflect on Process • Did your problem-solving process lead you to the correct answer? Version 1
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If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about diffusion. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that ions could diffuse across the membrane without the aid of transport proteins? Did you think that a large nonpolar molecule, such as estrogen, would diffuse more rapidly than a small nonpolar molecule, like oxygen gas? 68) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about coupled transport of glucose and sodium. • What type of thinking is required? o You are being asked to apply your knowledge about coupled transport of glucose and sodium. Gather Content • What do you know about coupled transport of glucose and sodium? What other information is related to the question? o The active glucose transporter uses the Na+ gradient produced by the Na+/K+ pump as a source of energy to power the movement of glucose into the cell. In this system, both glucose and Na+ bind to the transport protein, which allows Na+ to pass into the cell down its concentration gradient, capturing the energy and using it to move glucose into the cell through a symporter. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If Na+ levels drop on the outside of a cell, less Na+ is available to move to the inside of the cell, bringing glucose along with it through the symporter. As a result glucose transport will decrease. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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o This question asked you to apply your knowledge about coupled transport of glucose and sodium. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that sodium and glucose were transported by an antiporter? Did you think that glucose transport was not linked to Na+ transport? 69) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about water uptake in plants. • What type of thinking is required? o You are being asked to apply your knowledge about water uptake in plants. Gather Content • What do you know about water uptake in plants?What other information is related to the question? o Water diffuses from a hypotonic region to a hypertonic region. Most plant cells are hypertonic to their immediate environment, containing a high concentration of solutes in their central vacuoles. The resulting internal hydrostatic pressure, known as turgor pressure, presses the plasma membrane firmly against the interior of the cell wall, making the cell rigid. Most green plants depend on turgor pressure to maintain their shape, and thus they wilt when they lack sufficient water. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If a plant is wilted it needs to be placed in a hypotonic solution, so that the inside of the plant is hypertonic. This will allow water to enter the plant and restore its shape. The correct answer is to place the plants in a 5% solution so that water will enter the plant cells. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about water uptake in plants. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that water moves from a hypertonic solution to a hypotonic solution? Did you think that a wilted plant needs to lose more water? 70) D Clathrin-coated vesicles are associated with receptor mediated endocytosis. 71) Section Break 71.1) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about osmosis. • What type of thinking is required? o You are being asked to apply your knowledge about osmosis. Gather Content • What do you know about osmosis? What other information is related to the question? o In osmosis, water moves from an area that is hypotonic to an area that is hypertonic. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If egg 3 lost weight, then water was leaving the egg. If the solution was 15% salt, then it was hypertonic relative to the egg, pulling water from the egg. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about osmosis. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize that water was leaving the egg which made it lose weight? Did you think Version 1
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that water moved towards a hypotonic solution? 71.2) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about osmosis. • What type of thinking is required? o You are being asked to apply your knowledge about osmosis. Gather Content • What do you know about osmosis? What other information is related to the question? o In osmosis, water moves from an area that is hypotonic to an area that is hypertonic. If no water moves then the areas are isotonic Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If egg 3 did not change weight, then water was not entering or leaving the egg. If the solution was 15% salt, then it was isotonic relative to the egg. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about osmosis. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize that water was not leaving or entering the egg? Did you think that water Version 1
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moved towards a hypotonic solution? 71.3) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about osmosis. • What type of thinking is required? o You are being asked to apply your knowledge about osmosis. Gather Content • What do you know about osmosis? What other information is related to the question? o In osmosis, water moves from an area that is hypotonic to an area that is hypertonic. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If egg 1 gained weight, then water was entering the egg. If the solution was 15% salt, then the egg was hypertonic relative to the solution. This caused water to enter the egg. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about osmosis. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize that water was entering the egg which made it gain weight? Did you Version 1
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think that water moved towards a hypotonic solution? 72) Section Break 72.1) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about carrier proteins. • What type of thinking is required? o You are being asked to analyze a graph on carrier proteins. Gather Content • What do you know about carrier proteins? What other information is related to the question? o Carriers must bind to the molecule they transport, so the relationship between concentration and rate of transport differs from that due to simple diffusion. As concentration increases, transport by simple diffusion shows a linear increase in rate of transport. But when a carrier protein is involved, a concentration increase means that more of the carriers are bound to the transported molecule. At high enough concentrations all carriers will be occupied, and the rate of transport will be constant. This means that the carrier exhibits saturation. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Saturation occurs when the number of glucose molecules exceed the ability of the carrier proteins available to bind them. So at higher concentrations glucose saturates the carrier protein. Reflect on Process • Did your problem-solving process lead you to the correct Version 1
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answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze a graph on carrier proteins. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that the carrier proteins were saturated at lower concentrations of glucose? Did you think that saturation occurred at middle concentrations of glucose? 72.2) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about factors that affect the rate of diffusion. • What type of thinking is required? o You are being asked to apply your knowledge about factors that affect the rate of diffusion. Gather Content • What do you know about factors that affect the rate of diffusion? What other information is related to the question? o Diffusion relies on the rapid movement of molecules. This occurs most rapidly in warmer temperatures when the molecules are moving faster. The greater the difference in concentration across a membrane, the larger the gradient and the faster molecules will diffuse. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Diffusion will increase as the concentration of glucose increases. A decrease in temperature will decrease the rate of diffusion. pH should not affect the rate of diffusion of glucose since it is not charged. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more Version 1
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desirable result? o This question asked you to apply your knowledge about factors that affect the rate of diffusion. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that as glucose levels decrease diffusion would increase? Did you think that lower temperature would increase the rate of diffusion?
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Chapter 06 13e MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 1) Why do we have storage macromolecules, such as fats, in our bodies? A) We can break downthese macromolecules to provide energy for the endergonic reactions in ourbodies. B) Human cells can directly capture the energy of sunlight throughphotosynthesis and store it as macromolecules such as fats. C) Macromolecules,such as fats, are a convenient way to store kinetic energy. D) Breaking downmacromolecules, such as fats, is an endergonic process.
2)
Energy is defined as A) heat. B) the capacity to dowork. C) change. D) movement.
3)
The amount of energy available to do work is called A) activationenergy B) free energy C) kinetic energy D) potential energy
4) The energy needed to destabilize existing chemical bonds and start a chemical reaction is called A) activationenergy B) free energy C) kinetic energy D) potentialenergy
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5) Based on the graph, what are the optimal temperatures for the human enzyme (blue line) and hotsprings prokaryote enzyme (red line)?
Copyright© The Mc-Graw-Hill Companies,Inc, Permission Required for reproduction or display. A) The optimal temperature for the human enzyme is 30 degrees C. The optimal temperature for the hotsprings prokaryote enzyme is 60 degrees C. B) The optimal temperature for the human enzyme is 40 degrees C. The optimal temperature for the hotsprings prokaryote enzyme is 72 degrees C. C) The optimal temperature for the human enzyme is 46 degrees C. The optimal temperature for the hotsprings prokaryote enzyme is 79 degrees C. D) The optimal temperature for the human enzyme is 35 degrees C. The optimal temperature for the hotsprings prokaryote enzyme is 65 degrees C.
6) A drug binds to the active site of an enzyme. If it is bound to the active site of the enzyme, it prevents substrate binding. This drug would be considered a(n) A) noncompetitive inhibitor. B) allosteric inhibitor. C) allosteric activator. D) competitive inhibitor.
7) A particular reaction has a negative ΔG. However, this reaction takes many years to proceed in the absence of enzyme. Why is this the case?
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A) This reaction does not obey the second law of thermodynamics B) This reaction doesnot proceed spontaneously C) The initial freeenergy of the reactants is much less than the final free energy of theproducts D) A certain amountof activation energy is required for the reaction to proceed
8) A molecule that closely resembles the shape of a substrate for an enzyme and that decreases the activity of the enzyme would most likely serve as a(n) A) noncompetitive inhibitor. B) allosteric inhibitor. C) competitive inhibitor. D) allosteric activator.
9)
Oxidation and reduction reactions are chemical processes that result in a gain or loss of: A) atoms. B) neutrons. C) electrons. D) molecules. E) protons.
10) The synthesis of sugar molecules through the process of photosynthesis requires energy absorbed from sunlight. Bearing this in mind, what kind of reaction is photosynthesis? A) exergonic B) endergonic C) catabolic D) feedback
11) A particular chemical reaction is exergonic. What can you say about the relationship between the reactants and the products in this exergonic reaction?
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A) The reactants havemore free energy than the products B) The reactants arelikely more disordered and the products are likely more ordered C) The reactantscannot spontaneously react to generate the products D) The reactantslikely have lower enthalpy than the products
12) Kinases are enzymes that can phosphorylate (transfer phosphate groups onto) macromolecules such as proteins. A particular kinase, Kinase 1 is known to promote cell division. It promotes cell division by phosphorylating Protein X. Phosphorylation of Protein X activates Protein X. Once activated, Protein X stimulates the production of other proteins such as Protein Y and Z that directly promote cell division. In order to function, Kinase 1 requires the presence of Metal A. However, in the presence of Protein A, Kinase 1 is nonfunctional. From the description, what is considered the substrate of Kinase 1? A) Protein X B) Protein Y C) Protein Z D) Metal A E) Protein A
13) Kinases are enzymes that can phosphorylate (transfer phosphate groups onto) macromolecules such as proteins. A particular kinase, Kinase 1 is known to promote cell division. It promotes cell division by phosphorylating Protein X. Phosphorylation of Protein X activates Protein X. Once activated, Protein X stimulates the production of other proteins such as Protein Y and Z that directly promote cell division. In order to function, Kinase 1 requires the presence of Metal A. However, in the presence of Protein A, Kinase 1 is nonfunctional. From the description, what is considered a cofactor of Kinase 1? A) Protein X B) Protein Y C) Protein Z D) Metal A E) Protein A
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14) Hexokinase is an enzyme that binds specifically to glucose and converts it into glucose 6phosphate. The activity of hexokinase is suppressed by glucose 6-phosphate, which binds to hexokinase at a location that is distinct from the active site. This is an example of. A) feedback inhibition. B) competitive inhibition. C) cofactor binding. D) allosteric activation.
15)
The organic nonprotein components that aid in enzyme functioning are called A) reactants. B) chaperones. C) coenzymes. D) substrates. E) products.
16)
The inorganic nonprotein components that participate in enzyme catalysis are known as A) coenzymes. B) cofactors. C) products. D) substrates. E) reactants.
17) Many metabolic pathways are ultimately concerned with ATP; either with the generation of ATP, or with the requirement of ATP for that pathway to function. Why is ATP so important to metabolism?
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A) Hydrolysis of ATPis used to drive exergonic reactions B) Hydrolysis of thebond between adenine and ribose in ATP is commonly used to release energy thatcan be used to drive other cellular reactions C) The phosphategroups of ATP are held together by unstable bonds that can be broken to releaseenergy D) ATP is a proteinthat serves as the energy currency of cells
18)
The chemistry of living systems representing all chemical reactions is called A) catabolism. B) anabolism. C) metabolism. D) enzymology. E) thermodynamics.
19)
A calorie is the commonly used unit of chemical energy. It is also the unit of A) light. B) magnetism. C) sound. D) heat. E) radioactivity.
20) The term oxidation is derived from the name of the element oxygen. This is reasonable, because oxygen A) attracts electrons very strongly. B) can be oxidized by accepting electrons. C) contains more electrons than are needed. D) passes electronsto many other types of molecules.
21)
When an atom or molecule gains one or more electrons, it is said to be:
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A) energized. B) oxidized. C) polarized. D) reduced.
22)
The ultimate source of energy for humans comes from what source? A) The sun B) Plants C) Water D) Air E) Animals
23) Glucose is broken down through cellular respiration, which involves a large number of chemical reactions. At the end of the cellular respiration process, a large number of ATP molecules are generated, but yet, not all of the possible energy that is contained in a molecule of glucose can be harnessed through these chemical reactions to generate ATP. In other words, during cellular respiration, not all of the energy that is contained in a molecule of glucose is converted into the energy stored in ATP. What happens to the remaining energy? A) It isdestroyed B) It is used todrive exergonic reactions C) It is donated tomolecules in the cellular respiration process to reduce them D) It is lost asheat
24)
The Law of Thermodynamics that states that energy cannot be created or destroyed is: A) The First Law ofThermodynamics B) The Second Law ofThermodynamics C) The Third Law ofThermodynamics D) The Fourth Law ofThermodynamics
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25)
The Law of Thermodynamics that states that increases in entropy are favored is: A) The First Law ofThermodynamics B) The Second Law ofThermodynamics C) The Third Law ofThermodynamics D) The Fourth Law ofThermodynamics
26) A current problem in modern medicine is the development of drug resistant mutations. This occurs when a mutation arises in a disease-causing microbe making it resistant to a drug and thus rendering the drug useless. Many drugs are competitive inhibitors of specific enzymes, and the drug-resistant mutations prevent the binding of the drug. These types of mutations, in addition to preventing competitive inhibitor binding, can also reduce the activity of the enzyme. Why is that the case? A) Binding to thecompetitive inhibitor is essential for the function of the enzyme B) These mutationsmost likely affect an allosteric site on the enzyme C) These mutationslower the activation energy of the reaction catalyzed by the enzyme D) These mutationsmost likely change the shape of the active site of the enzyme
27) Tacrolimus (FK-506) is a drug that inhibits an enzyme called calcineurin. Calcineurin is a protein phosphatase. This is an enzyme that dephosphorylates (removes phosphate groups) from proteins. When added to cells, tacrolimus can inhibit the dephosphorylation of a protein called NFAT, but it cannot prevent the dephosphorylation of a protein called CDK1. What is the most likely explanation for this finding? A) Calcineurin requires an additional cofactor to dephosphorylate NFAT B) NFAT is a substrate of calcineurin, but CDK1 is not C) Tacrolimus is a competitive inhibitor of calcineurin for NFAT and CDK11 D) Tacrolimus changesthe optimum pH for calcineurin
28)
RNA molecules that also act as enzymes are given the name
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A) ribozymes B) cofactors C) coenzymes D) allostericenzymes
29)
In an enzyme-catalyzed reaction, the reactant is called the A) coenzyme B) catalyst C) substrate D) product
30) When the substrate is bound to the enzyme, the shape of the enzyme may change slightly, leading to A) an induced fit B) a great range ofpossible catalytic activities C) a greater supplyof activation energy D) more permanentbinding through intimate total contact E) more possibleproducts of the reaction
31) In order to reuse an enzyme after the conclusion of an enzyme catalyzed reaction, what must occur? A) the enzyme hasto be resynthesized B) the enzyme has toseparate itself from the product C) changes into anactive form D) the enzyme has todecrease entropy
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32) You are working with a specific enzyme-catalyzed reaction in the lab. You are a very careful scientist, and as a result, at the beginning of each of your experiments, you measure the temperature in the lab. On days 1 through 5, the temperature in the lab was 20oC. Today is day 6 of your experiment, and the temperature in the lab is 30oC. How do you predict that this will alter the rate of your enzyme-catalyzed reaction? A) It will decreasethe rate B) It will increasethe rate C) It could possiblyincrease or decrease the rate D) it will not affectthe rate
33) Metabolic reactions fall under two general categories: anabolic and catabolic. What type of chemical reactions are these two classes of metabolic reactions? A) Anabolic reactionsare exergonic reactions, whereas catabolic reactions are endergonic. B) Both anabolic and catabolic reactions are exergonic. C) Both anabolic and catabolic reactions are endergonic. D) Anabolic reactionsare endergonic reactions, whereas catabolic reactions are exergonic.
34)
Under standard conditions, ATP can release for every molecule converted to ADP A) less than 1 cal of energy. B) 1 to 2 cal of energy. C) 7.3 Kcal of energy. D) different amounts of energy depending on the cell.
35) Glucose is converted into glucose 6-phosphate by hexokinase. Glucose 6-phosphate then serves as the substrate for the enzyme phosphoglucose isomerase, which converts this reactant into fructose 6-phosphate. Fructose 6-phosphate serves as the substrate for phosphofructokinase, which converts fructose 6-phosphate into fructose 1,6-bisphosphate. Based on the information provided, this is an example of what?
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A) Feedbackinhibition B) Allostericregulation C) A metabolicpathway D) Enzymeinhibition
36) In an experiment described in a chemistry lab book, the directions state that after mixing two chemicals (A and B) and waiting 5 minutes, chemical A will be oxidized. This means that: A) chemical A has lost electrons to chemical B. B) chemical A has gained electrons from chemical B. C) chemical A hasgained energy in the form of heat from chemical B. D) chemical A haslost energy in the form of heat to chemical B. E) chemical A hasreacted with oxygen.
37) In a chemical reaction, glyceraldehyde-3-phosphate + NAD+ yields 1,3bisphosphoglycerate + NADH. In this reaction, what happened to NAD+? A) It was oxidized toform NADH B) It was reduced toform NADH C) It was activatedto form NADH D) it served as anenzyme to catalyze the reaction, and at the end of the reaction formed NADH
38) In a chemical reaction, 1,3-bisphosphoglycerate + ADP yields 3-phosphoglycerate plus ATP. What is the ΔG for this reaction? A) Greater thanzero. B) Less thanzero. C) Equal tozero. D) Cannot bedetermined
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39) For a particular chemical reaction, the enthalpy of the reactants is -400 kJ. The enthalpy of the products is -390 kJ. The entropy of the reactants is 0.2 kJ/K. The entropy of the products is 0.3 kJ/K. The temperature of the reaction is 25 degrees Celsius. What can you conclude about this reaction? A) It isexergonic B) It isendergonic C) it is a redoxreaction D) It is beingcatalyzed by an enzyme
40)
Does ADP contain the capacity to provide energy for the cell?
A) No. ADPdoes not contain any bonds that can be broken to provide energy for thecell. B) Yes. ADPhas the same capacity to provide energy for the cell as ATP. C) Yes. Cleaving the bond between the ribose sugar and the two phosphate groupscan provide energy for the cell. D) Yes. Cleaving the bond between the terminal phosphate and the phosphateattached to the ribose sugar can provide energy for the cell.
41) AMP-activated protein kinase (AMPK) is an enzyme that is activated by high levels of AMP in cells. If levels of AMP are high in cells, that means that levels of ATP are low. Once active, AMPK activates catabolic pathways and inhibits anabolic pathways in the cell. Why do you think that is the case? Choose the answer that best explains the role of AMPK. A) High levels ofAMP indicate that there is a high amount of energy stored in the cell, thusactivating catabolic pathways and inhibiting anabolic pathways are mechanismsto use stored energy. B) By inhibitinganabolic pathways, AMPK provides a mechanism to generate heat for thecell, which is important if AMP levels are high in the cell. C) By activating catabolic pathways, AMPK provides a mechanism to activateexergonic pathways, which is important if AMP levels are high in the cell. D) Activatingcatabolic pathways and inhibiting anabolic pathways will ultimately lead tohigher consumption of ATP, which is important if AMP levels are high in thecell.
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42) You are studying an enzyme-catalyzed reaction that induces a particular cellular activity in the lab. If you wanted to slow down that particular cellular activity by controlling the enzyme, what could you do? A) Decrease thetemperature of the incubator where the cells are growing B) Increase the pHof the media the cells are growing in to the optimum pH C) Add cofactors tothe media the cells are growing in D) Add an allostericactivator to the cells
43) A new antibiotic has been developed. It acts as a noncompetitive inhibitor of an enzyme. How will this antibiotic affect Δ G for the reaction that is catalyzed by the enzyme? A) Δ G will increase B) Δ G will decrease C) Δ G will be unaffected
44) Glycolysis is a metabolic process that is conducted by nearly all cells. However, in addition to glycolysis, some cells also make use of another metabolic process called the Krebs cycle. What does this tell you about the evolution of these processes? A) As a metabolic process, glycolysis likely evolved prior to the Krebs cycle B) As a metabolic process, the Krebs cycle likely evolved prior to glycolysis C) Both the Krebscycle and glycolysis likely evolved at the same time
45) Enzyme 1 converts substrate A into product B. Is this an example of a metabolic pathway? A) Yes. This isa metabolic pathway that includes feedback inhibition. B) No. Thisonly describes one chemical reaction. A metabolic pathway includesmultiple chemical reactions. C) Yes. This isa simple metabolic pathway. D) No. Ametabolic pathway must include an inhibitory step.
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46) It is summer, and you are excited about going to your local amusement park, and specifically about riding the new roller coaster that was just built. You imagine waiting at the top of the stairs for the roller coaster to pull into the station, climbing into the car, strapping yourself into the seatbelt, and pulling down the harness. You can imagine the cars slowly chugging up to the top of the first hill, coming down on the other side, and the excitement you expect to feel as you go along for the ride. Of all of the things that you have imagined, which is an example of potential energy? A) Waiting at the topof the stairs for the roller coaster to pull into the station B) Climbing into thecar C) Pulling down theharness D) The roller coastercar going up the first hill
47) Phosphofructokinase (PFK) is an enzyme that converts fructose 6-phosphate to fructose 1,6-bisphosphate, by adding a phosphate group. This is the first committed step of the metabolic pathway of glycolysis, and thus it is very tightly regulated. AMP binds to PFK at a site distinct from the binding site for fructose 6-phosphate, and stimulates the formation of fructose 1,6bisphosphate. ATP binds to PFK at a site distinct from the binding site for fructose 6-phosphate, and inhibits the formation of fructose 1,6-bisphosphate. There are other regulators of this enzyme as well. What is the role of AMP in this example? A) Competitiveinhibitor B) Noncompetitiveinhibitor C) Allostericinhibitor D) Allostericactivator E) Catalyst
48) You eat a bowl of beans as part of your dinner. As you digest the beans, the proteins that are present get broken down to their component amino acids. As your body destroys the macromolecules that were present in the beans, is the energy present in those molecules destroyed?
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A) Yes. Bybreaking down these macromolecules, some of the energy they contained isdestroyed. B) No. While thevast majority of the energy contained in these macromolecules is converted toheat, it is not actually destroyed. C) No. Theenergy contained within these macromolecules is converted into other forms ofchemical energy and kinetic energy, though some is lost as heat. D) No. Breakingdown molecules does not lead to the release of energy.
49) If you were able to increase the kinetic energy of the molecules inside your body, how would this affect your body temperature? A) It wouldincrease B) It woulddecrease C) It would remainthe same
50) You return home to find that your baby brother has scattered his toy trains and trucks all over the floor of your room. As you begin to pick up the toys and put them away, you realize that even though he is just a baby, he has clearly mastered: A) the first law of thermodynamics. B) the second law of thermodynamics. C) potential energy. D) free energy.
51)
If the ΔG of a reaction was -31.45 kJoules, you would know that: A) the products havemore free energy than the reactants. B) the reaction requires an energy input of 31.45 kJoules to proceed. C) the reaction mostlikely leads to development of a more ordered system. D) the reaction isspontaneous.
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52) In the hypothetical biochemical pathway, P → Q + R → S → T, which step is likely to have evolved first? A) P → Q B) Q + R C) R → S D) S → T
53) While conducting an experiment, you realize that a competitive inhibitor was interfering with your reaction. How could you overcome this problem? A) Add a noncompetitive inhibitor to the reaction. B) Add a cofactor tothe reaction. C) Increase theconcentration of the correct substrate in the reaction. D) Add an allostericactivator to the reaction.
54) of.
A ribozyme catalyzes a reaction on itself and actually changes shape. This is an example
A) intra-enzyme reactions. B) inter-enzyme reactions. C) intramolecular catalysis. D) intermolecular catalysis.
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Answer Key Test name: Chap 06_13e_Raven 1) A Fat molecules have many bonds, and breaking those bonds provides energy, as discussed in the text. Therefore, these macromolecules are a convenient way of storing energy, and stored energy is considered potential energy. Human cells cannot perform photosynthesis. Breaking down macromolecules is an exergonic process. 2) B 3) B 4) A 5) B The optimal temperature is the peak if the graph
6) D 7) D Reactions with a -ΔG proceed spontaneously, but not instantaneously. They need a certain amount of activation energy to proceed. 8) C
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Clarify Question What is the key concept addressed by the question? • The question asks you to identify a molecule that closely resembles the shape of an enzyme's substrate and that decreases the enzyme's activity. What type of thinking is required? • You are being asked to take what you already know about enzymes and molecular shape and apply your understanding to determine which role is most likely. Gather Content What do you already know about enzymes and inhibition? What other information is related to the question? • To solve this problem you’ll need to apply what you know about the different ways that enzyme regulation can occur and determine the most likely role for a molecule that has a similar shape to the substrate and that decreases enzyme function. Recall that enzyme function can be decreased by both competitive and noncompetitive inhibition and also that enzyme function can be decreased by allosteric inhibition or increased by allosteric activation. Why is the shape of substrate molecules important, and what would be the role of a molecule that mimics the substrate’s shape and decreases enzyme function? Choose Answer Do you have all the information needed to answer the question? • At this point, you should have everything you need to answer the question. Remember that enzyme function can be inhibited competitively and noncompetitively and can also be allosterically inhibited or activated. What are the key differences between these Version 1
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methods? • Let’s consider noncompetitive inhibition first. Noncompetitive inhibition means molecules that decrease the enzyme's function are not trying to outcompete substrate molecules for the enzyme’s active site. As such, the shape of noncompetitive inhibitors is unlikely to closely match the shape of the substrate molecule. • Likewise, allosteric regulators, which are noncompetitive by definition, bind at a site remote from the active site to either increase (activators) or decrease (inhibitors) enzyme function. Again, the shape of an allosteric inhibitor or activator is unlikely to closely resemble the shape of a substrate molecule because it doesn’t need to function as a mimic. • That leaves competitive inhibition as the only viable option, but why does that make sense? First, the molecule is decreasing the enzyme's function, so it is an inhibitor. Second, the molecule closely resemble the substrate’s shape, so it can serve as a competitive inhibitor, fitting into the same space as the substrate molecule at the active site of the enzyme and outcompeting the substrate molecule for access to the enzyme's active site. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to use your understanding of enzymes and regulation to determine what the most likely function would be for a molecule that closely resembles the substrate and that decreases enzyme activity. • If you got an incorrect answer, did you recall the ways in which enzymes can be regulated? Did you understand that inhibitors act to Version 1
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decrease an enzyme's function? Did you remember that noncompetitive and allosteric inhibition don’t involve the active site, and therefore the shape of noncompetitive inhibitors or allosteric inhibitors would have no need to resemble the substrate’s shape? Were you able to rationalize competitive inhibition considering that the shape of the inhibitor resembled the substrate? 9) C 10) B Because this process requires energy input, it is an endergonic reaction. 11) A
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Clarify Question What is the key concept addressed by the question? • The question asks for you to determine the relationship between reactants and products in an exergonic reaction. What type of thinking is required? • You are being asked to take what you already know about enzymes and free energy and apply your understanding to determine the energy characteristics of an exergonic reaction. Gather Content What do you already know about the energy associated with reactants and products in reactions? What other information is related to the question? • To solve this problem you’ll need to apply what you know about the free energy associated with reactants and products and determine how it is associated with exergonic and endergonic reactions. What free energy characteristics determine whether or not a reaction is exergonic (spontaneous) or endergonic (nonspontaneous)? Choose Answer Do you have all the information needed to answer the question? • Recall that the change in free energy in enzyme-based reactions is classified as exergonic or endergonic. Exergonic reactions have a negative Δ G and are spontaneous, whereas endergonic reactions have a positive Δ G and are nonspontaneous. Remember also that nonspontaneous reactions can be made to work if there is sufficient investment of energy (e.g. coupled reactions). • The only way to be able to meet the criteria for an exergonic reaction is to choose an answer that will create a negative Δ G. In practical terms, Version 1
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that means the free energy of the reactants must be higher than the free energy of the products. All other answer choices are implausible because they violate that basic energy assumption. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to use your understanding of reactions and free energy to determine the energy characteristics for an exergonic reaction. • If you got an incorrect answer, did you remember that reactions can be classified as exergonic and endergonic based on whether or not their change in free energy is positive or negative? Did you remember that exergonic reactions have a negative Δ G and endergonic reactions have a positive Δ G? Were you able to infer from this information that the reactant must have more free energy than the products in order to obtain a negative Δ G? 12) A Since kinases function to phosphorylate macromolecules, and Kinase 1 phosphorylates Protein X, Protein X is considered a substrate of Kinase 1. 13) D Metal A is required for Kinase 1 to function, and thus is a cofactor for this kinase. 14) A In this case, the product of the reaction, glucose 6-phosphate, is feeding back to inhibit the enzyme that catalyzes the reaction, hexokinase. As a result, this is an example of feedback inhibition.
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15) C 16) B 17) C ATP serves as the energy currency of cells, storing energy in its triphosphate group. By cleaving the unstable bonds holding the phosphates together in an ATP molecule, energy can be released to drive endergonic reactions. ATP can also be used as a building block for RNA molecules. It is not a protein. 18) C 19) D 20) A 21) D 22) A 23) D It is lost as heat. In fact, this is one of the ways we maintain our body temperature. 24) A 25) B 26) D
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Clarify Question What is the key concept addressed by the question? • The question asks you ascertain how drug resistance development in bacteria is related to reduced enzyme activity. What type of thinking is required? • You are being asked to break down, or analyze, a possible means by which drug resistance in bacteria might work to reduce enzyme activity. Gather Content What do you already know about enzymes and how their activity is regulated? How does this drug affect enzyme activity under normal circumstances? What other information is related to the question? • Remember that the activity of an enzyme is directly related to its structure and function. Recall that there are several structural elements of an enzyme that affect its function; these include the active site and the allosteric site. These structural elements as well as inhibitors influence an enzyme’s ability to facilitate reactions. The question also indicates that the drug acts as a competitive inhibitor of the enzyme. Considering the structure and function of enyzmes, what would most directly affect bacterial drug resistance by reducing enzyme activity? Choose Answer Do you have all necessary information to analyze how drug resistance would reduce enzyme activity? • The first major clue in this question is that the drug is a competitive inhibitor of the enzyme, and that microbial changes in the enzyme’s structure render the drug ineffective. Recall that competitive inhibitors mimic the shape of a substrate, which binds to the active site. This information implies that the shape of the drug was a close match to the Version 1
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substrate in order to be a competitive inhibitor in the first place. • A second major clue is the mutation in the bacterium also renders the drug ineffective. • These two lines of evidence imply that the active site of the enzyme must be directly involved, since neither the allosteric site nor the activation energy of the enzyme would be affected. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • This question asked you to analyze possible reasons for why a previously-effective drug that works as a competitive inhibitor is rendered ineffective by bacterial mutation. • If you got the answer correct, well done! If you got an incorrect answer, were you able to break down the structural elements of the enzyme into the active and allosteric sites? Were you able to correlate the two lines of evidence of the drug being a competitive inhibitor and the bacterial mutation eliminating drug effectiveness? Were you able to infer from this evidence that the active site was the most likely aspect of the enzyme to be affected? 27) B
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Clarify Question What is the key concept addressed by the question? • The question asks you determine the likely explanation for why the drug tacrolimus works in cells to inhibit the enzyme calcineurin, prevent dephosphorylation of NFAT, and maintain phosphorylation of CDK1. What type of thinking is required? • You are being asked to break down, or analyze, a possible means by which the drug tacrolimus works on calcineurin phosphatase enzyme. Gather Content What do you already know about phosphates and enzyme structure? What other information is related to the question? • Since calcineurin is an enzyme, that means it works to convert substrates to products – just like any other enzyme. In the case of this enzyme, calcineurin dephosphorylates other proteins. The trick to answering this question correctly is to try and decipher how NFAT and CDK1 relate to calcineurin. • Let’s consider the options. How would calcineurin function if NFAT were a cofactor? A substrate? How might tacrolimus work if it were a competitive inhibitor of calcineurin? Is it possible for tacrolimus to change the operating pH of calcineurin? If you take it one step at a time, what is the likely role of calcineurin on NFAT and CDK1? Choose Answer Do you have all necessary information to analyze how tacrolimus works on NFAT and CDK1? • It is unlikely that tacrolimus would affect calcineurin’s pH. Enyzmes operate in very specific pH ranges and if tacrolimus affected pH, other enzymes besides calcineurin would also be affected. Version 1
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• The question mentions nothing about any cofactors needed for calcineurin to dephosphorylate NFAT. • If tacrolimus were a competitive inhibitor of calcineurin, it would interact with the enzyme as a substrate but prevent calcineurin’sdephosphorylation activity, leading to greater phosphorylation of NFAT and CDK1. The question indicates that tacrolimus acts to prevent dephosphorylation of NFAT but not CDK1, so that answer is not plausible. • That leaves NFAT as a substrate of calcineurin, which makes sense when you consider that adding tacrolimus prevents NFAT being dephosphorylated by calcineurin. CDK1 is unaffected, as indicated in the question. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • This question asked you to determine the likely explanation for relationships between calcineurin, NFAT, and CDK1 proteins based on tacrolimus treatment. • If you got the answer correct, good job! If you got an incorrect answer, were you able to decipher that tacrolimus results in less calcineurin activity and therefore less NFAT dephosphorylation? Were you able to correlate the activity of calcineurin and NFAT together? Were you infer that their relationship would only be possible if NFAT were a substrate for calcineurin? 28) A 29) C 30) A 31) B Version 1
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32) C
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Clarify Question What is the key concept addressed by the question? • The question asks you predict what effect temperature change will have on the rate of an enzyme-catalyzed reaction. What type of thinking is required? • You are being asked to weigh and judge, or evaluate, which prediction is most plausible from a given change in environmental temperature. Gather Content What do you already know about enzyme rates and temperature? What other information is related to the question? • Remember that temperature affects protein structure and function, and as such can influence the enzyme rate of reaction because enzymes are proteins. The real question here is to predict how a 10 degree temperature change might affect enzyme reaction rate. Choose Answer Do you have all necessary information to make a judgment? • Recall that enzyme protein structure and function operates best within a relatively narrow window. Therefore, enzyme reaction rates will fluctuate, depending on the degree of temperature change. • The enzyme rates could increase if the 10 degree temperature increase brings the enzyme closer to its optimal temperature. Conversely, enzyme reaction rates could decrease if the optimal temperature is closer to the 20 degree room temperature. Without more information, it is impossible to predict how exactly the enzyme rates will change, so the most acceptable prediction is to say that enzyme reaction rates could increase or decrease. Version 1
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • This question asked you to predict the effects of environmental temperature on enzyme reaction rates. • If you got the answer correct, good job! If you got an incorrect answer, did you remember that enzymes are proteins, and that temperature affects protein structure and function? Did you recall that enzymes operate best at an optimal temperature? Were you able to determine that enzyme rates could increase or decrease due to the 10 degree environmental temperature change? 33) D Anabolic reactions expend energy to build up molecules, and thus are endergonic reactions. Catabolic reactions harvest energy by breaking down molecules, and thus are exergonic. 34) C 35) C 36) A 37) B
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine what happens to NAD+ during a chemical reaction. What type of thinking is required? • You are being asked to break down, or analyze, the chemical reaction to determine what happens to NAD+. Gather Content What do you already know about oxidation and reduction chemical reactions? What other information is related to the question? • Remember that many chemical processes participate in oxidation and reduction (redox) reactions. Oxidation reactions occur when electrons are liberated from a molecule whereas reduction reactions occur when electrons are added to a molecule. Reduction is frequently associated with addition of hydrogen atoms as well. • As you may remember, redox reactions are quite common in biochemical pathways such as the reactions described in the question. Given what you know about the participants in redox reactions, what happens to NAD+ when it becomes NADH? Choose Answer Do you have all the information needed to determine the correct answer? • Redox reactions involve one molecule becoming oxidized and another molecule becoming reduced via the removal and addition of electrons, respectively. • NAD+ is a molecular acceptor of electrons, and is therefore an oxidized molecule. The question indicates that NADH is a product of the Version 1
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reaction. So what is the relationship between NAD+ and NADH? • When NAD+ accepts electrons, it becomes reduced. The reduced form of NAD+ is therefore NADH. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • This question asked you to determine what happens to NAD+ in the reaction. • If you got the answer correct, good work! If you got an incorrect answer, did you remember how redox reactions occur? Were you able to identify which molecules participated in redox reactions? Were you able to discover what happened to NAD+ when it became NADH? 38) B
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Clarify Question What is the key concept addressed by the question? • The question asks for you to determine the free energy characteristics for a chemical reaction. What type of thinking is required? • You are being asked to take what you already know about enzymes and free energy and apply your understanding to determine the energy characteristics of the enzyme-based reaction. Gather Content What do you already know about free energy in enzymatic reactions? What other information is related to the question? • To solve this problem you’ll need to apply what you know about free energy and how it is associated with different types of enzyme reactions. What free energy characteristics determine whether a reaction will occur or not? • What clues does the question give you about Δ G? Does the reaction require the breakdown of ATP or produce ATP? What types of reactions require ATP hydrolysis in order to run? Choose Answer Do you have all the information needed to answer the question? • Recall that the change in free energy in an enzyme-based reaction is classified as exergonic or endergonic. Exergonic reactions with a negative ΔG are spontaneous, whereas endergonic reactions with a positive ΔG are nonspontaneous. Remember also that nonspontaneous reactions can be made to work if there is sufficient investment of energy (e.g. coupled reactions). • Since the question says nothing about the need to invest energy such Version 1
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as ATP, that is one clue that the reaction is exergonic and has a negative ΔG. Another clue is the reaction shows that ADP is converted to ATP rather than the other way around. The lack of ATP hydrolysis and coupling to an endergonic reaction indicates that the reaction must not have a positive ΔG (which would indicate an endergonic reaction). Clearly, an energy conversion of some kind has occurred, so ΔG definitely does change. The only suitable option left would be a negative ΔG, which is corroborated by both the clues and the process of elimination. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to use your understanding of enzymes and free energy to determine what the free energy change would be for the reaction. • If you got an incorrect answer, did you remember that enzyme reactions can be classified as exergonic and endergonic based on whether or not their change in free energy is positive or negative? Did you remember that exergonic reactions have a negative Δ G and endergonic reactions have a positive Δ G? Were you able to see that ADP eventually formed ATP and infer that the reaction would have to be exergonic and therefore would have a negative Δ G? 39) A
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Clarify Question What is the key concept addressed by the question? • The question asks you to draw a conclusion about a reaction given different energy parameters of reactants and products. What type of thinking is required? • You are being asked to dissect, or analyze, several energy parameters of a reaction in order to arrive at a conclusion. Gather Content What do you already know aboutenergy of reactants and products in a reaction? What other information is related to the question? • Remember that the total energy (enthalpy or H) in a chemical system is equal to the amount of free energy (G) minus the amount of disorder (entropy) at a particular temperature (T, in Kelvin). Thus, H = G – TS. • Recall also that ΔG equals the difference in energy level from the beginning to the end of the reaction, such that ΔG = Δ H – T(Δ S). Consider also that reactions that have a negative Δ G are considered to be exergonic (spontaneous), whereas positive Δ G reactions are endergonic (nonspontaneous). • How is the overall Δ G of a reaction determine once you have values for total energy (enthalpy) and wasted energy (entropy)? Choose Answer Do you have all the information needed to make a determination about the change in free energy? • Recall that Δ G refers to the amount of energy that changes from the beginning to the end of the reaction, and is equal to the total change in enthalpy (Δ H) minus the product of temperature (T, in Kelvin) and disorder (S). Version 1
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• Let’s unpack this solution by first comparing the total energy between products and reactants. If you compare the enthalpy (total energy) of the products and reactants, you will find the change in enthalpy is -390kJ –(400kJ), which equals 10kJ. • Next let’s determine the disorder component, which is the product of entropy and temperature in Kelvin. Change in entropy is 0.3kJ/K – 0.2kJ/K and equals 0.1 kJ/K. The temperature in Kelvin is 25 degrees Celsius + 273K and equals 298K. • Finally, the change in free energy is determined by change in enthalpy minus the disorder component. Thus, Δ G = (10-(298*0.1)), which equals (10-29.8), which produces a final answer of -19.8. Since the change in free energy is negative for this reaction, it is exergonic. Note that it cannot be concluded from the description whether this is a redox reaction, or whether it is being catalyzed by an enzyme. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • This question asked you to analyze energy characteristics for a reaction to determine whether it is exergonic, endergonic, redox, or enzyme-catalyzed. • If you got the answer correct, well done! This was a more challenging problem to solve. If you got an incorrect answer, did you recall how ΔG is different between exergonic and endergonic reactions? Were you able to calculate the change in free energy based on the information provided? Based on that information, were you able to show the reaction had a negative ΔGand based on that must be exergonic? 40) D
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While ADP does not have the same capacity to provide energy for the cell as ATP, cleaving the terminal phosphate of ADP has the capacity to release energy for the cell, as this is a high-energy bond. 41) C
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine the role of AMPK in balancing catabolic and anabolic pathways in cells. What type of thinking is required? • You are being asked to dissect, or analyze, a scenario to ascertain the role of AMPK in cells. Gather Content What do you already know about AMP, ADP, and ATP in cells? What other information is related to the question? • Remember that ATP is the energy currency of the cell. High levels of ATP indicate the cell is fully powered and has the energy reserves it needs to conduct cellular work. Recall also that ADP and AMP are lower-level and lowest-level energy molecules, respectively. • If the cell is in an energy deficit, which molecule will be most prevalent: ATP, ADP, or AMP? Choose Answer Do you have all the information needed to make a determination about the change in free energy? • If AMP levels are high in the cell, this indicates that energy levels in the cell are low. This in turn means that the cell would have lower levels of ATP, the high-energy currency of the cell. • Recall that AMP can be converted to ADP and then to ATP by adding inorganic phosphate. When energy levels are low (AMP), the cell needs to generate more high energy molecules (ATP). This requires the cell to turn on energy-generating exergonic pathways and turn off endergonic pathways that require energy. Since reactions that break chemical bonds Version 1
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in molecules are required to capture stored energy and generate ATP, and reactions that require energy to build molecules are less needed, AMPK will most likely activate catabolic pathways and inhibit anabolic pathways. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • This question asked you to analyze the most likely role of AMPK in cells when AMP levels are high and ATP levels are low. • If you got the answer correct, congratulations! If you got an incorrect answer, were you able to correlate AMP levels with low energy and ATP levels with high energy in the cell? Were you able to determine that catabolic reactions are required to generate ATP and anabolic reactions require ATP? Were you able to connect the two ideas together to determine that high AMP levels would lead to increased catabolic (exergonic) and decreased anabolic (endergonic) reactions? 42) A Decreasing the temperature could work to slow down the reaction. All of these other choices would either increase or maintain the rate of the reaction. 43) C
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Clarify Question What is the key concept addressed by the question? • The question asks you ascertain how an antibiotic that noncompetitively inhibits an enzyme will affect the reaction’s change in free energy. What type of thinking is required? • You are being asked to break down, or analyze, how a noncompetitive inhibitor antibiotic will influence an enzyme-catalyzed change in free energy. Gather Content What do you already know about enzymes and free energy? What other information is related to the question? • Remember that an enzyme helps to accelerate the rate of a reaction by making the reaction more likely to occur. Recall that noncompetitive inhibitors bind not to the active site, but to an enzyme’s secondary site which changes the protein’s three-dimensional conformation, changes the shape of the active site, and thereby reduces the overall speed of the reaction. • Considering the structure and function of enyzmes and how noncompetitive inhibitors work, how might the free energy of the reaction be affected? Choose Answer Do you have all necessary information to analyze how the noncompetitive inhibitor might influence free energy? • Recall that a noncompetitive inhibitor binds to a secondary site on the enzyme, which changes the shape of the enzyme and precludes the substrate from binding to the active site. Thus, the enzyme will be Version 1
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unable to catalyze the reaction, only the uncatalyzed pathway of the reaction can occur, and the reaction will proceed much more slowly. • Regardless of how fast the reaction can proceed, with or without the enzyme, the actual difference in free energy between the reactants and the products will not change. Whether or not a reaction is exergonic or endergonic is a function of whether or not the reaction has a positive or negative Δ G. The presence of an enzyme, or a noncompetitive inhibitor, has no effect on the difference in free energy. As a result, the noncompetitive inhibitor antibiotic should have no effect on the free energy required for the reaction. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • This question asked you to analyze the effect of a noncompetitive inhibitor antibiotic on the free energy of a reaction. • If you got the answer correct, well done! If you got an incorrect answer, did you remember how noncompetitive inhibitors affect an enzyme's activity? Were you able to determine that free energy, or the difference in free energy from reactants to products, doesn’t change regardless of the presence or absence of enzyme catalysis? 44) A
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Clarify Question What is the key concept addressed by the question? • The question is asking about the evolutionary implications of the fact that glycolysis is used by nearly all cells but the Krebs cycle is not. What type of thinking is required? • You are being asked to break down, or analyze, if one of the processes, glycolysis or the Krebs cycle, likely evolved before the other or if they likely evolved at the same time. Gather Content What do you already know about evolution and time? What other information is related to the question? • Remember that evolution is a series of changes that occur over time. Evolution is shaped by several factors, including natural selection that confers greater biological fitness for a pre-existing genetic makeup within a given environment. • Recall also that the greater numbers of species that share a trait, the older the trait or the more important the trait may be. Given this context and considering that nearly all organisms use glycolysis but not all use the Krebs cycle, what conclusions can you draw? Choose Answer Do you have all necessary information to determine the relative importance of glycolysis and the Krebs cycle? • Glycolysis is used by nearly all cells to metabolize energy. Because it is such a widely-shared trait across different life forms, it is likely important to survival and has likely been in existence longer in evolutionary history than the Krebs cycle, which is not as widely used among different types of cells. Version 1
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • This question asked you to analyze the relative appearance of glycolysis versus the Krebs cycle in evolutionary history. • If you got the answer correct, excellent! If you got an incorrect answer, did you remember how evolution occurs? Were you able to infer how biologically relevant glycolysis is based on its prevalence across life forms in nature? Were you able to compare its likely timing of evolution relative to that of the Krebs cycle based on this information? 45) B 46) A This is the only choice where you or the roller coaster car are not moving. At the top of the stairs, you have gravitational potential energy. 47) D
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine the role of AMP in regulating the PFK enzyme in the glycolysis metabolic pathway. What type of thinking is required? • You are being asked to dissect, or analyze, how AMP works to regulate the activity of the PFK enzyme based on the scenario. Gather Content What do you already know about enzymes, feedback inhibition, and glycolysis? What other information is related to the question? • Remember that several enzymes can function together in a biochemical pathway, and the efficient regulation of that pathway frequently involves feedback inhibition, which occurs when the final product regulates an earlier step in the pathway. • In glycolysis, PFK is a critical rate-setting enzyme that can be regulated to work faster or slower, depending on environmental conditions. What molecules are likely to help increase PFK activity when the cell needs more energy and decrease PFK activity when it needs less energy via glycolysis? Choose Answer Do you have all the information needed to determine how AMP helps to regulate PFK activity? • Recall that biochemical pathways are a series of enzyme-regulated chemical reactions. Control of a key enzyme in the pathway helps to regulate the entire pathway. • In order to regulate a key enzyme like PFK, you need the enzyme to be able to sense when there is too little or too much energy available. Version 1
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Carefully managing the cell’s resources by tailoring energy metabolism is key to efficiency and survival. • Consider that ATP is an important, high-energy molecule used by the cell to power its processes. If a cell has enough ATP, would it be useful and efficient for that cell to make more when it already has enough? When enough ATP is present, it will bind to PFK and down-regulate its activity so that more ATP isn’t made until it is needed. • Conversely, when energy levels are too low in the cell, you want to move molecules through glycolysis in order to make more ATP. But how does the cell sense when energy levels are low? It needs a sensory molecule, which in this case is AMP. AMP is a low-level energy molecule, and acts as an effective sensor for PFK and glycolysis. So how does it work? AMP can bind to an allosteric site on PFK, which activates PFK and increases the rate of glycolysis, which results in greater ATP production. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • This question asked you to analyze a possible role for AMP in regulating PFK and glycolysis. • If you got the answer correct, fantastic! If you got an incorrect answer, did you remember how biochemical pathways work? Were you able to determine how PFK is regulated based on key role in glycolysis? Were you able to infer how AMP works as a sensor and activates PFK? 48) C 49) A
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Clarify Question What is the key concept addressed by the question? • The question asks for you to determine how increased kinetic energy in your body might affect your body temperature. What type of thinking is required? • You are being asked to take what you already know about potential and kinetic energy and apply your understanding to determine how increased kinetic energy might affect body temperature. Gather Content What do you already know about potential and kinetic energy? What other information is related to the question? • To solve this problem you’ll need to apply what you know about kinetic energy and use this to infer what might happen to body temperature. • Remember that kinetic energy is energy associated with things in motion. What effect does temperature have on objects in motion? Choose Answer Do you have all the information needed to answer the question? • Objects in motion are affected by temperature. Think about it: when something is frozen, it is immobile, and its kinetic energy is very low or absent. The opposite would also be true: if you could increase the kinetic energy of your body, the molecules that make up your body would be in motion, more then normal. This would increase the number of contact events between molecules, which would elevate the cellular temperature and thus your body temperature. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to use your understanding of kinetic energy and relate it to temperature. If you got an incorrect answer, did you remember that kinetic energy is energy associated with objects in motion? Did you remember that objects in motion frequently generate friction, and friction generates heat? Were you able to apply that understanding to predict that body temperature would increase as kinetic energy increases? 50) B 51) D 52) D
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine which step in a biochemical pathway most likely evolved first. What type of thinking is required? • You are being asked to break down, or analyze, the steps in a biochemical pathway to determine the most suitable targets for early evolution. Gather Content What do you already know about evolution? What other information is related to the question? • Remember that evolution is a series of changes that occur over time. Evolution is shaped by several factors, including natural selection: selection that confers greater biological fitness for a pre-existing genetic makeup within a given environment. • A trait that evolved could convey greater biological fitness to some members of a population as compared to others without that trait for a given environment. The same can be said of molecules in a biochemical pathway. Inherited genetic changes that lead to molecular variation which in turn affects pathway productivity could provide enhanced function for the cells that contain them. That said, which steps in the biochemical pathway are most likely to be foundational to function and thus evolved first? Choose Answer Do you have all necessary information to break down the biochemical pathway? • There are 5 components in the biochemical pathway, starting with P Version 1
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and eventually leading to T. Of these 5 components, which is most likely to have the key outcome and function? That would most likely be product T, which is the function end product and most likely to be used directly in cellular structure and/or function. • Working backwards from there, the steps that are most directly connected to product T represent the core chemistry in the pathway, which in this case is S -> T. All the other steps in the pathway are essentially preparation to get to the functional end point of product T. Being the most central to the pathway’s function, the S -> T reaction is likely to have evolved first. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • This question asked you to determine which steps in a biochemical pathway are most likely to have evolved first. • If you got the answer correct, excellent! If you got an incorrect answer, did you remember how evolution occurs? Were you able to break down the steps in a biochemical pathway and determine which is most important? Were you able to infer the evolutionary significance of this step? 53) C
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Clarify Question What is the key concept addressed by the question? • The question asks for you to overcome a problem where a competitive inhibitor is interfering with a reaction. What type of thinking is required? • You are being asked to take what you already know about enzymes and competitive inhibition and apply your understanding to determine how to rectify the problem. Gather Content What do you already know about enzymes and competitive inhibition? What other information is related to the question? • To solve this problem you’ll need to apply what you know about how competitive inhibition regulates enzyme function. Recall that enzyme function can be inhibited competitively, noncompetitively, and allosterically. How does competitive inhibition compare to the other types of inhibition, and keeping that mechanism in mind, what could you do to overcome the inhibition? Choose Answer Do you have all the information needed to answer the question? • The question indicates that a competitive inhibitor is messing up your reaction. If you added a noncompetitive inhibitor, you would like still end up with decreased enzyme functionality because it changes the enzyme structure and prevents substrate binding altogether. An allosteric inhibitor would essentially function in the same way as a noncompetitive inhibitor, and likewise not help your reaction. • A cofactor might conceivably help overcome the latent inhibition, but only if the cofactor outcompeted the inhibitor for the active site. Version 1
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• That leaves increasing substrate concentration as the best solution. Recall that with competitive inhibition, the inhibitor directly competes with the substrate for the enzyme’s active site. Both inhibitor and substrate try to occupy the same physical space within the structure of the enzyme. Increasing substrate concentration would serve up more reactants to the active site per unit time than the inhibitor, effectively washing out the effects of the inhibitor. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to use your understanding of enzymes and competitive inhibition to determine what would be the most likely solution to restore your reaction. • If you got an incorrect answer, did you recall how competitive inhibition works? Did you contrast that with noncompetitive and allosteric inhibition, which don’t involve the active site and therefore wouldn’t solve the problem at all? Were you able to decipher that the best solution was to simply outcompete the competitive inhibitor by increasing substrate? 54) C
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Chapter 07 13e MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 1) Organisms that can manufacture their own chemical energy are called_________blank. A) autotrophs B) heterotrophs C) oligotrophs D) chemotrophs
2) Organisms that depend on the energy stored in chemical bonds by other organisms for their food energy are called_________blank. A) Autotrophs B) Heterotrophs C) Oligotrophs D) Chemotrophs
3) Animals that take in oxygen from their environment break down glucose into carbon dioxide and water in a process called A) anaerobic respiration. B) organic compound respiration. C) glucose respiration. D) aerobic respiration.
4)
In glycolysis, a major portion of the energy remains in the final product, which is called A) glucose. B) citrate. C) glyceraldehyde 3-phosphate (G3P). D) pyruvate.
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5) One way to generate acetyl-CoA is to convert pyruvate into acetyl-CoA by stripping off a CO2 molecule. The removal of CO2 is referred to as what type of reaction? A) Decarboxylation B) Glycolytic C) Carboxylation D) Acetylation
6) All of the reactions of cellular respiration that occur after glycolysis take place in what part of the eukaryotic cell? A) Thechloroplast B) The nucleus C) Themitochondria D) The plasmamembrane E) The cytoplasm
7)
What must happen to amino acids before they can be used in catabolic reactions? A) They must bedecarboxylated B) They must bedeoxygenated C) They must bedehydrogenated D) They must bedeaminated
8) Many types of cancer cells secrete significant levels of lactate. Do you think it is likely these cells are undergoing beta-oxidation?
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A) Yes, becausebeta-oxidation can generate intermediates that would lead to the production oflactate. B) No, because if lactate is being produced, the cell is not likely making use of the pathways needed to make use of the products of beta-oxidation. C) Yes, becauselactate stimulates beta-oxidation. D) No, becauselactate is consumed in beta-oxidation
9) What stage of cellular respiration can occur in human cells with or without oxygen present? A) The Citric acid cycle B) Glycolysis C) The electrontransport chain D) Pyruvateoxidation
10) When oxygen is unavailable during heavy exercise, what process do muscle cells use for energy generation? A) Glycolysiscoupled with alcohol fermentation B) Anaerobicrespiration C) Aerobicrespiration D) Glycolysiscoupled with lactate fermentation
11) What oxidizing agent is used to temporarily store high energy electrons harvested from glucose molecules in a series of gradual steps in the cytoplasm? A) FADH2 B) ADP C) NAD+ D) Oxygen
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12) is
It is thought that the oldest stage of cellular respiration from an evolutionary perspective
A) the Citric acid cycle. B) the electron transport chain. C) fermentation. D) glycolysis.
13) A human cell has a mutation in the gene that encodes the enzyme that generates lactate from pyruvate, rendering that enzyme completely non-functional. Assuming that there is ample glucose present, how would this cell generate energy in the presence of oxygen? A) Glycolysis coupledwith ethanol fermentation B) Aerobicrespiration C) Primarily through the break down of proteins into amino acids D) This cell wouldhave no way to generate energy under these conditions because it cannot carryout the reactions needed for glycolysis
14)
What molecule can oxidize NADH? A) Acetaldehyde B) Lactate C) Ubiquinone D) Glucose E) Isocitrate
15)
In aerobic respiration, chemiosmotic generation of ATP is driven by: A) Pi transfer through the plasma membrane. B) the Na+/K+ pump. C) a difference inH+ concentration on the two sides of the innermitochondrial membrane. D) osmosis of macromolecules. E) large quantities of ADP.
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16) In the reaction: C4H6O4 + FAD →C4H4O4 + FADH2, what type of reaction took place to remove the protons from C4H6O4? A) Decarboxylation B) Reduction C) Dehydrogenation D) Oxidation
17)
How and where is ATP made in a eukaryotic cell?
A) ATP is only made inthe mitochondria in response to chemiosmosis. B) ATP is made in all compartments of the cell in response to endergonic reactions and is used to drive exergonic reactions in the cell. C) ATP can be made by direct phosphorylation of ADP in the cytoplasm, and by an enzyme complex that uses the energy from a proton gradient to drive ATP synthesis in the mitochondria. It can also be made in other locations in the cell, depending on the cell type. D) ATP can be made byan enzyme complex that uses the energy of protons moving down theirconcentration gradient from the mitochondrial matrix to the cytoplasm to makethe ATP.
18) If you take into account the amount of ATP generated by ATP synthase per molecule of NADH produced in aerobic respiration, the net number of ATP molecules produced by substratelevel phosphorylation, and the fact that NADH molecules produced in the cytoplasm have to be transported into the mitochondria, what is the predicted energy yield of glycolysis in eukaryotic cells? A) 2 ATP B) 5 ATP C) 7 ATP D) 32 ATP E) 30 ATP
19)
During what step of glycolysis are two ATP molecules required?
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A) Cleavage andrearrangement B) Glucosepriming C) Oxidation D) Pyruvateformation E) Acetyl-CoAformation
20)
This process is common to all living cells: A) Glycolysis B) Alcoholfermentation C) The Citric acid cycle D) Electron transportchain reactions E) Pyruvateoxidation
21) If you take into account the amount of ATP generated by ATP synthase per molecule of NADH and per molecule of FADH2 produced, and the number of ATP molecules produced by substrate-level phosphorylation, what is the predicted energy yield of the Citric acid cycle, per molecule of glucose in eukaryotic cells? A) 18 ATP B) 2 ATP C) 10 ATP D) 20 ATP E) 30 ATP
22)
What is an end-product of glycolysis? A) Oxaloacetate B) NAD+ C) Alcohol D) ADP E) Pyruvate
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23) The equation for cellular respiration is: C6H12O6 + 6O2 6CO2 + 6H2O. At what specific point in the cellular respiration process has glucose been broken down completely from a six carbon molecule to 6 molecules of CO2? A) During the primingreactions in glycolysis B) During theoxidation and ATP formation reactions in glycolysis C) During pyruvateoxidation D) During the condensation reaction in the Citric acid cycle E) During the second oxidation in the Citric acid cycle
24)
Pyruvate oxidation in eukaryotic cells occurs in the _________blank. A) cytoplasm B) nucleus C) Golgi body D) mitochondria E) plasma membrane
25)
What is common to all of the oxidation reactions in the Citric acid cycle?
A) They all lead tothe generation of NADH. B) They are alldecarboxylation reactions. C) They are allcharacterized by a loss of electrons from an organic molecule coupledto the reduction of an electron acceptor. D) They all lead tosubstrate-level phosphorylation of ADP to generate ATP.
26) In the reaction catalyzed by aconitase, the conversion of citrate to isocitrate is inhibited by fluoroacetate. Fluoroacetate is used as a pesticide. Why is this an effective pesticide?
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A) It inhibitsglycolysis B) It inhibitspyruvate oxidation C) It inhibits the Citric acid cycle D) It inhibits theelectron transport chain E) It inhibits ATPsynthase
27) Arsenic poisoning can lead to organ failure and death. Though arsenic can inhibit or interfere with a number of cellular enzymes, arsenic poisoning is thought to be mainly due to indirect inhibition of enzymes involved in both pyruvate oxidation and the Citric acid cycle. As a result, this compound must be able to enter which cellular compartment? A) The cytoplasm B) The nucleus C) The intermembranespace of the mitochondria D) The mitochondrialmatrix E) The endoplasmic reticulum
28)
What are the products of one turn of the Citric acid cycle? A) 1 CO2,2 NADH, 1 FADH2, 1 ATP B) 2 CO2,3 NADH, 1 FADH2, 1 ATP C) 2 CO2,6 NADH, 2 FADH2, 2 ATP D) 4 CO2,6 NADH, 2 FADH2, 2 ATP E) 4 CO2,12 NADH, 4 FADH2, 4 ATP
29) What is different about the way that NADH and FADH2 donate electrons to the electron transport chain?
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A) NADH is oxidized and FADH2 is reduced. B) NADH contributesits electrons to the first transmembrane complex in the electron transportchain and FADH2 contributes its electronsafter the first transmembrane complex. C) More protons are transported into the intermembrane space of the mitochondria in response to one molecule of FADH2 as compared to the number of protons transported in response to one molecule of NADH. D) The electrons from NADH ultimately go on to reduce oxygen to generate water, whereas the electrons from FADH2 are used to reduce pyruvate to lactate.
30)
What happens to the oxygen that is used in cellular respiration? A) It is converted tocarbon dioxide B) It is used to makeglucose C) It is used to make Citric acid cycle intermediates D) It is reduced toform water E) It is converted toacetyl-CoA
31) As electrons move along the electron transport chain, they lose potential energy. How is the energy that is released used by the cell? A) The energy isused to transport protons against their concentration gradient B) The energy isused to pump electrons along the electron transport chain C) The energy isconverted directly into ATP D) The energy isused to pump NAD+ into the cytoplasm so it can be used inglycolysis
32) Cardiac muscle cells need to generate significant amounts of ATP to allow for constant contractile activity. As a result, they primarily depend upon beta-oxidation of fatty acids, which has a higher energy yield than the catabolism of glucose. What would be the ATP yield for betaoxidation of a hypothetical 10-carbon fatty acid?
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A) 32 ATP B) 35 ATP C) 50 ATP D) 62 ATP E) 65 ATP
33) The energy released in the mitochondrial electron transport chain is used to transport protons into the A) mitochondrial matrix. B) cytoplasm. C) endoplasmic reticulum. D) intermembrane space of the mitochondria. E) nucleus.
34) If citrate levels are high in the cell, but ATP levels are low, what do you think will happen in the cell? A) In the presence of glucose, glycolysis will run to generate energy for the cell, but the Citric acid cycle will be inhibited. B) Glycolysis will be inhibited, but the Citric acid cycle will be functional, allowing it to be utilized to breakdown acetyl-CoA generated from beta-oxidation. C) The electron transport chain will be inhibited, causing a build-up of NADH and FADH2. This will inhibit the Citric acid cycle, but in the presence of glucose, glycolysis will still run coupled with fermentation to regenerate NAD+. D) Glycolysis and the Citric acid cycle will both be inhibited, thus under these conditions there will be no mechanism to generate ATP.
35) Regardless of the electron or hydrogen acceptor used, one of the products of fermentation is always
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A) ADP. B) ATP. C) NAD+. D) pyruvate. E) alcohol.
36) Glucose is not our only food source, nor the only one we can utilize in our bodies to generate energy. Other primary sources of energy include other sugars, proteins, and fats.What metabolic intermediate are fats primarily converted into? A) Pyruvate B) Acetyl-CoA C) Citric acid cycle intermediates D) Electrontransport chain components E) ATP Synthase
37) When amino acids are degraded in cells, into what intermediate(s) of the aerobic respiration process are the carbon skeletons of amino acids primarily converted? A) Pyruvate B) Acetyl-CoA C) Citric acid cycle intermediates D) Pyruvate andacetyl-CoA E) Pyruvate and Citric acid cycle intermediates
38) A biochemist wants to control the initial substrate-level phosphorylation that occurs in the tracheal cells of grasshoppers once glucose has crossed the plasma membrane. He has access to the following inhibitors: Rotenone, an electron transport chain inhibitor; Oligomycin, an ATP synthase inhibitor; and TLN-232, an inhibitor of glycolysis. Which inhibitor should he use to slow down initial substrate-level phosphorylation that occurs once glucose has crossed the plasma membrane?
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A) Rotenone B) Oligomycin C) TLN-232 D) None of theseinhibitors would be effective in preventing substrate-level phosphorylation
39) To form NADH from NAD+, two electrons and a proton are removed from an organic molecule. What term best describes the reaction in which electrons and a proton are removed from an organic molecule? A) Condensation B) Reduction C) Dehydrogenation D) Decarboxylation E) Isomerization
40) Aerobic respiration involves the transfer of several electrons from glucose to electron carriers such as NAD+ over a series of steps, and ultimately glucose reacting with oxygen to generate carbon dioxide, water and energy. Why does glucose not react directly with oxygen in cells? A) Oxygen cannotaccept electrons, and thus an electron carrier like NAD+ is needed. B) Oxygen and glucoseare localized in different subcellular compartments. C) The direct reaction of oxygen with glucose would be extremely destructive to cells. D) The reaction ofoxygen with glucose is not spontaneous.
41)
When substrate-level phosphorylation occurs, it means that: A) NAD+ isconverted into NADH. B) ATP is convertedinto ADP plus a phosphate group. C) ADP is convertedinto ATP by the addition of a phosphate group. D) NADH is convertedinto NAD+ plus a proton.
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42) What is the net number of ATP generated directly during glycolysis per molecule of glucose? A) 0 B) 2 C) 4 D) 6 E) 8
43) The Citric acid cycle occurs in the mitochondria. There are nine biochemical reactions involved in the Citric acid cycle, and they are highly ordered. Select the correct order. (Note: These are abbreviated and do not show NAD, ADP, ATP, or FAD.) A) acetyl-CoA joins the Citric acid cycle and unites with oxaloacetate →forming citrate →which forms beta-ketoglutarate → which forms succinyl-CoA → which forms succinate → which forms fumarate → which forms malate → which forms oxaloacetate B) acetyl-CoA joins the Citric acid cycle and unites with oxaloacetate →forming citrate →which forms alpha-ketoglutarate → which forms succinyl-CoA → which forms succinate → which forms malate → which forms fumarate → which forms oxaloacetate C) acetyl-CoA joins the Citric acid cycle and unites with oxaloacetate →which forms alpha-ketoglutarate → forming citrate → which forms succinyl-CoA → which forms succinate → which forms fumarate → which forms malate → which forms oxaloacetate D) acetyl-CoA joins the Citric acid cycle and unites with oxaloacetate →forming citrate →which forms alpha-ketoglutarate → which forms succinyl-CoA → which forms succinate → which forms fumarate → which forms malate → which forms oxaloacetate
44)
How many oxidation reactions occur during the Citric acid cycle? A) 1 B) 2 C) 4 D) 6 E) 9
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45) What would be the ATP yield for a molecule that is catabolized to form one molecule of pyruvate in a eukaryotic cell? A) 10 ATP B) 12.5 ATP C) 25 ATP D) 30 ATP E) 11.5 ATP
46) What is the oxidized form of the most common electron carrier that is needed for both glycolysis and the Citric acid cycle? A) ATP B) FAD C) pyruvate D) NAD+ E) acetyl-CoA
47) Many of the antiviral drugs currently used to treat HIV/AIDS also interfere with an enzyme that helps mitochondria multiply. Treatment can therefore result in a decrease in the number of mitochondria found in certain tissues. Given this information, what might you expect to see in patients treated with antiviral drugs? A) An increase inoxidative phosphorylation B) An increase inphosphofructokinase activity C) An increase in NADHdehydrogenase activity D) An increase inlactic acid levels
48) Cytochromes contain a heme group similar to that in hemoglobin. The iron atom (Fe) in the center of the group can be oxidized and reduced. If someone was suffering from iron deficiency anemia, what stage of cellular respiration would be most affected?
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A) Glycolysis B) The Citric acid cycle C) The electrontransport chain D) Fermentation
49) As a forensic pathologist, you have just completed an autopsy of a poisoning victim. After a thorough examination, you conclude that the victim died of cyanide poisoning. You know that cyanide binds to the cytochrome oxidase complex, and therefore list the official cause of death as suffocation due to cyanide exposure. However, if you wanted to provide a more technical explanation as to the cause of death, which process was specifically inhibited directly by cyanide? A) The reduction ofNAD+ B) The oxidation ofFADH2 C) All proton pumpinginto the intermembrane space D) The formation ofwater from oxygen E) ATP synthesis
50) Phosphofructokinase is regulated by a number of factors, including high levels of ATP. Why is this enzyme regulated by ATP levels? A) If ATP levels are high, this provides a mechanism to directly inhibit the Citric acid cycle, thus preventing further generation of NADH, FADH2 and ATP molecules that are not needed. B) If ATP levels arehigh, it is important to directly inhibit the reaction that commits thesubstrate to glycolysis to allow the substrate to be available for otherreactions, since the cell has ample energy. C) If ATP levels arehigh, it is important to inhibit ATP synthase, and phosphofructokinase directlyinhibits ATP synthase. D) If ATP levels are high, this provides a mechanism to directly inhibit theelectron transport chain, thus preventing the formation of a proton gradient inthe intermembrane space of mitochondria.
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A) ATP B) Acetyl-CoA C) Pyruvate D) Oxygen
52)
In the absence of oxygen, can cells utilize the electron transport chain?
A) Yes, all cells canmake use of the electron transport chain in the absence of oxygen viafermentation. B) No, oxygen is arequired cofactor for the complexes in the electron transport chain. C) Yes, if a cell can use a terminal electron acceptor other than oxygen, it can make use of the electron transport chain. D) No, oxygen is theprimary electron acceptor in electron transport chains in all cell types.
53) Your friend is having difficulty keeping track of the energy flow from glucose through glycolysis, the Citric acid cycle and electron transport. Your best advice would be to A) follow ATP production. B) follow theprotons. C) follow NAD+ production. D) follow theelectrons.
54) If ATP synthase had a mutation in the F1 complex portion of the protein, which function of ATP synthase would most likely be affected? A) The rotation of the rotor B) The flow of protons through the channel C) The conversion of ADP and Pi to ATP D) The insertion of the enzyme into the membrane
55)
What aspect of cellular respiration occurs in the cytoplasm in eukaryotic cells?
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A) Glycolysis B) Pyruvateoxidation C) The Citric acid cycle D) The electrontransport chain E) ATP synthesis
56) You decide to go on vacation in the mountains, where you are staying in a cabin. Unfortunately, when you turn on the water in the cabin you smell hydrogen sulfide (H2S) gas. After some research, you find out that the H2S may be due to the presence of sulfur bacteria living in your pipes. What molecule do these bacteria use as an electron acceptor? A) O2 B) H20 C) SO4 D) H2S
57) In order to lose weight and reduce body fat, a friend of yours has decided to eliminate all fat from his diet, while consuming unrestricted amounts of carbohydrates. What do you think of this idea? A) It is a good idea,because if your friend doesn't eat any fat, he cannot store any additionalfat. B) It is a bad idea,because consumption of fat is required to provide cofactors for the electrontransport chain. C) It is a good idea,because under conditions where ATP levels are low in cells, carbohydrates willbe stored, and fat stores will be catabolized via beta-oxidation to generateenergy. D) It is a bad idea,because if ATP levels are high in cells, excess acetyl-CoA from the metabolismof carbohydrates can be used for fatty acid synthesis.
58) Why are the components of the electron transport chain embedded in the inner mitochondrial membrane rather than floating freely in the cytoplasm of the mitochondrial matrix?
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A) To generate andmaintain the proton gradient essential for ATP production. B) To separate the ATPfrom the ADP. C) Because electronscannot float in the matrix. D) Because NADHcannot localize to the mitochondrial matrix.
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Answer Key Test name: Chap 07_13e_Raven 1) A 2) B 3) D 4) D 5) A 6) C 7) D 8) B
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Clarify Question What is the key concept addressed by the question? • The question asks you to decide whether or not cancer cells that secrete lactate are undergoing beta-oxidation. What type of thinking is required? • You are being asked to dissect, or analyze, the likelihood that cancer cells that secrete lactic acid are undergoing beta-oxidation. Gather Content What do you already know about lactate fermentation? How do products from this process indicate how cancer cells derive energy? What other information is related to the question? • Recall that cellular respiration is a process of oxidizing glucose in order to produce NADH and ultimately the ATP used to power cellular processes. Respiration is comprised of glycolysis, the oxidation of 3carbon into 2-carbon molecules which then are incorporated into the Citric acid cycle, and electron transport and oxidative phosphorylation. With the exception of glycolysis, all of these processes are related to aerobic respiration. • At the end of glycolysis, cells can choose to use aerobic processes like the Citric acid cycle if there is sufficient oxygen available, or they can use anaerobic processes like lactic acid fermentation if there is no oxygen. Cancer cells in particular tend to use anaerobic processes. • Recall that molecules other than glucose are metabolized for energy in cells; this includes breakdown of fatty acids and glycerol and, in certain circumstances, proteins into amino acids. Each of these molecules plugs into cellular respiration in different places and under different conditions. The process of breaking down fatty acids is called betaVersion 1
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oxidation and involves cutting the fatty acid into two carbon fragments (acetyl-CoA) that plug into the Citric acid cycle. Choose Answer Do you have all necessary information to determine which products would affect cellular respiration? • The Warburg effect, discovered by Otto Warburg and since confirmed by observations from other scientists, indicates that many cancer cells derive their energy mainly through the glycolytic pathway coupled with lactic acid (lactate) fermentation. If lactate is produced, that suggests these cells are not engaging in aerobic respiration, including the Citric acid cycle, and/or the electron transport chain. This is because cancer cells are using fermentation to regenerate NAD+, instead of using the electron transport chain. • Since beta-oxidation generates acetyl-CoA, which can only be used in the Citric acid cycle, the observation that these cells are generating lactate suggests that they are not undergoing beta-oxidation. Betaoxidation does not lead to generation of intermediates that can lead to lactate production, nor does lactate stimulate beta oxidation, and lactate is not consumed through the process of beta-oxidation. • Cancer cells use anaerobic processes to generate lactate, and since beta-oxidation of fatty acids requires oxygen, cancer cells that operate in the absence of oxygen aren’t using beta-oxidation. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze Version 1
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whether or not cancer cells that secrete higher levels of lactate are likely undergoing beta-oxidation. • If you got the correct answer, well done! If you got an incorrect answer, were you able to recall the stages of cellular respiration that require oxygen? Were you able to correlate higher levels of lactate with anaerobic metabolism? Were you able to infer that the anaerobic conditions needed for lactate metabolism would prevent aerobic processes like beta-oxidation? 9) B 10) D 11) C 12) D 13) B
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine how a cell that can’t convert pyruvate into lactate would be able to generate energy in the presence of oxygen if ample glucose is present. What type of thinking is required? • You are being asked to dissect, or analyze, how a cell with a mutated enzyme for converting pyruvate into lactate would be able to generate energy, considering that plenty of oxygen and glucose are present. Gather Content What do you already know about how cells use multiple fuels to generate energy? How does this relate to the inability of the cell to convert pyruvate into lactate? What other information is related to the question? • Recall that cells are able to use multiple fuel sources, including carbohydrates, fats, and protein, as necessary. Carbohydrates are most easily metabolized, followed by fats and then proteins. The conditions under which each is metabolized during cellular respiration is largely determined by the internal and external environment and the energy needs of the cell. • At the end of glycolysis, cells can choose to use aerobic processes like the Citric acid cycle if there is sufficient oxygen available, or they can use anaerobic processes like lactic acid fermentation when there is no oxygen. In this question, the cell has a mutation that prevents the enzyme that converts pyruvate into lactate from functioning. This means that lactic acid fermentation is not an option. • Recall that glycolysis does not depend on whether the environment is aerobic or anaerobic; what happens to pyruvate at the end of glycolysis Version 1
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is dependent on environmental conditions. In this case, the question indicates there is plenty of oxygen, so downstream processes like the Citric acid cycle and electron transport are possible. Choose Answer Do you have all necessary information to determine which products would affect cellular respiration? • Let’s try to narrow down the possible options for this question. Recall that human cells are capable of lactic acid fermentation, not ethanol fermentation. Furthermore the question indicates there is plenty of glucose available, so there would be no need to break down proteins into amino acids to derive energy for the cell. Otherwise, the cell would have no problem going through glycolysis and, if conditions are right, carrying out the Citric acid cycle and electron transport to generate cellular energy. • The question also indicates that oxygen is present. If oxygen is present, these cells should have no problem doing aerobic respiration. Just because the cell contains a mutated enzyme and can’t convert pyruvate into lactate shouldn’t really matter, because there is plenty of oxygen around and nothing to prevent aerobic processes like the Citric acid cycle and electron transport chain from functioning normally. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze how a human cell that has a mutated enzyme and can’t convert pyruvate into lactate would generate energy assuming ample glucose and oxygen are available. • If you got the correct answer, excellent! If you got an incorrect Version 1
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answer, were you able to remember which stages of cellular respiration require oxygen and which do not? Were you able to eliminate ethanol fermentation and protein breakdown as less likely options? Were you able to infer that the cell could still participate in aerobic respiration because there was plenty of glucose and oxygen available? 14) A 15) C 16) C
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Clarify Question What is the key concept addressed by the question? • The question asks you to identify what type of reaction takes place when you remove protons from C4H604. What type of thinking is required? • You are being asked to use what you know about the loss and gain of electrons and protons during redox reactions and extend, or apply, that knowledge to determine what type of reaction takes place when you remove protons from C4H604. Gather Content What do you already know about redox reactions and electrons? What other information is related to the question? • Recall that oxidation-reduction, or redox, reactions occur when electrons are removed from (oxidation) or added to (reduction) a molecule. Remember that cells rely on redox reactions to harvest the high potential energy stored in electrons from broken bonds and do work in the cell. • During the breaking of bonds in carbohydrate molecules, high-energy electrons are freed. This reaction is also accompanied by the loss of a proton. If you lose a proton and an electron together, does this give you a clue as to what type of reaction is taking place? Choose Answer Do you have all necessary information to what type of reaction is taking place? • Breakdown of carbohydrates by the cell requires multiple steps, many of which involve redox reactions. Several reactions are provided as options. Decarboxylation is unlikely to have happened because nothing is changing to the number of carbons before or after the reaction takes place. A reduction reaction definitely happened, but that was to the FAD molecule, not the C4H604 molecule. C4H604 was also oxidized, but it lost protons as well. Remember that each time an electron is liberated, so too is a proton, which together make hydrogen and thus constitute a dehydrogenation reaction during oxidation. The most accurate answer is dehydrogenation. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to apply what you know about redox reactions and identify the type of reaction that took place to remove protons from C4H604. • If you got the correct answer, nice job! If you got an incorrect answer, were you able to read Version 1
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the reaction to determine which component had their protons removed? Were you able to see that electrons would also be removed? Were you able to correlate the removal of the protons and electrons to determine that a dehydrogenation reaction took place?
17) C 18) B
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine the predicted yield of ATP from NADH molecules associated from glycolysis. What type of thinking is required? • You are being asked to dissect, or analyze, glycolysis for ATP and NADH production to determine the total yield of ATP during glycolysis. Gather Content What do you already know about glycolysis and ATP and NADH yield? What energy costs are required to transport NADH produced in the cytosol via glycolysis into the mitochondria? What other information is related to the question? • Recall that the first part of cellular respiration is glycolysis, which occurs in the cytosol. Products from glycolysis include ATP and NADH, among other molecules. • Glycolysis requires energy investment, which takes away from the total number of ATP it can produce via substrate-level phosphorylation. NADH, another key product of glycolysis, holds high energy electrons that can ultimately be used to produce ATP via chemiosmosis and oxidative phosphorylation in the mitochondria using ATP synthase during electron transport. • How many ATP molecules can conceivably be produced in the mitochondria from one NADH molecule? Choose Answer Do you have all necessary information to determine which products would affect cellular respiration? • Remember that during glycolysis 4 total ATP are produced, 2 ATP Version 1
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need to be invested in the early stages, leaving a net of 2 ATP molecules produced overall. In addition, 2 molecules of NADH are produced during glycolysis. • Each molecule of NADH, whether made in the cytosol or in the mitochondria, will deposit their high-energy electrons into the electron transport chain. ATP synthase, the key enzyme that produces ATP via the chemiosmotic proton gradient, is predicted to yield 2.5 molecules of ATP per NADH molecule. Thus, during glycolysis, we generate 2 net ATP via substrate-level phosphorylation and another 5 for the 2 molecules of NADH that are produced. • However, each molecule of NADH generated by glycolysis has to be transported into the mitochondria via active transport, which requires 1 ATP molecule per NADH to be transported. • Therefore, the total energy yield of glycolysis in a eukaryotic cell should be: 2 ATP (glycolysis net ATP) + 5 ATP (2 NADH molecules from glycolysis making 2.5 ATP each during chemiosmosis) - 2ATP (NADH active transport into mitochondria) = 5 ATP. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze the different ways that ATP could be produced both during glycolysis as well as from glycolytic products and to account for the ATP costs across the board. • If you got the correct answer, well done! If you got an incorrect answer, were you able to accurately tally how many ATP were made via substrate-level phosphorylation in glycolysis? Did you consider how many ATP could be produced from the NADH molecules produced Version 1
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during glycolysis? Did you account for the energy costs associated with glycolysis itself as well as NADH active transport into the mitochondria? 19) B 20) A 21) D
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine the predicted ATP yield of the Citric acid cycle per molecule of glucose. What type of thinking is required? • You are being asked to dissect, or analyze, the Citric acid cycle to determine the total yield of ATP from a single glucose molecule. Gather Content What do you already know about the Citric acid cycle and yield? What other information is related to the question? • Recall that a key part of cellular respiration is the Citric acid cycle, which occurs in the mitochondria. Products from the Citric acid cycle include NADH, FADH2, and a few ATP, among other molecules. • The Citric acid cycle must be able to continuously receive acetyl-CoA, a 2-carbon molecule that is converted from a 3-carbon pyruvate (generated during glycolysis) immediately preceding the Citric acid cycle. Each 6-carbon glucose molecule is first broken into 2 3-carbon pyruvate molecules during glycolysis, which are in turn oxidized into 2 2-carbon acetyl-CoA molecules with 2 molecules of carbon dioxide produced as well. Each acetyl-CoA molecule is able to enter the Citric acid cycle. • At the beginning of the Citric acid cycle each 2-carbon acetyl-CoA molecule joins with a 4-carbon oxaloacetate molecule to form a 6carbon citrate molecule. In order to take in another acetyl-CoA, the 4carbon oxaloacetate has to be regenerated, prompting the release of 2 carbon dioxide molecules per pyruvate. Recall that each time a carbon dioxide molecule is produced, bonds are broken and high-energy electrons are released, which are captured by NADH. As it turns out, this kind of bond breaking happens several times per acetyl-CoA during the Version 1
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Citric acid cycle, prompting both NADH and FADH2 to be produced. • How many acetyl-CoA molecules are produced from one glucose molecule? What does that tell you about how many times the Citric acid cycle will turn per glucose? Choose Answer Do you have all necessary information to determine which products would affect cellular respiration? • As we figured out earlier, the Citric acid cycle runs twice per glucose molecule. This is because glucose is broken down into 2 molecules of pyruvate, each of which are converted into acetyl-CoA through pyruvate oxidation. Both acetyl-CoA molecules can enter the Citric acid cycle. • Remember that bond breakage produces high-energy electrons that are captured by NADH. This happens several times each time the Citric acid cycle turns, to produce 3 NADH, 1 FADH2, and 1 ATP molecule. Since the Citric acid cycle turns twice per glucose molecule, this means that 6 NADH, 2 FADH2, and 2 ATP are made. Since 2.5 ATP are made per NADH and 1.5 ATP are made per FADH2 from ATP synthase, the number of ATP that are made from high-energy electron carriers is 2.5 x 6 NADH + 1.5 x 2 FADH2 = 18 ATP. • Finally, remember that the Citric acid cycle also produces 1 ATP per turn via substrate-level phosphorylation. Since there are 2 turns per glucose, 2 ATP are made. When added to the 18 ATP produced from NADH and FADH2, the total is 20 ATP. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze the Citric acid cycle and the different ways that ATP could be produced Version 1
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from both NADH and FADH2 as well as substrate-level phosphorylation. • If you got the correct answer, good thinking! If you got an incorrect answer, were you able to accurately tally how many NADH and FADH2 molecules were produced during one turn of the Citric acid cycle? Did you realize that the Citric acid cycle turns twice per glucose? Were you able to calculate the number of ATP produced from NADH, FADH2 as well as the 2 ATP produced via substrate-level phosphorylation in the Citric acid cycle? 22) E 23) E
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine the point at which glucose has been completely broken down to carbon dioxide during cellular respiration. What type of thinking is required? • You are being asked to dissect, or analyze, cellular respiration to determine when the six carbon molecules in glucose have been completely oxidized to carbon dioxide. Gather Content What do you already know about cellular respiration and the oxidation of carbon? What other information is related to the question? • Recall that cellular respiration involves oxidizing carbon in glucose to become carbon dioxide. Consider each stage of cellular respiration: glycolysis, pyruvate oxidation, Citric acid cycle, and electron transport. Which of these stages involves the production of carbon dioxide? Why is carbon dioxide produced in the first place? Choose Answer Do you have all the information needed to determine at which point glucose is completely oxidized to carbon dioxide? • Let’s review each step of cellular respiration in order to determine the last point at which carbon dioxide is produced. Glycolysis involves converting a 6-carbon glucose molecule into 2 3-carbon pyruvate molecules. Hopefully it is clear that no carbon dioxide is lost during glycolysis, so no carbon oxidation has occurred. • Pyruvate oxidation involves conversion of the 2 3-carbon pyruvate molecules into 2 2-carbon acetyl-CoA molecules. Since matter can’t be created or destroyed, and you have to account for all of the carbon, the only way this can make sense is if 2 carbon dioxide molecules are given off during pyruvate oxidation. Since 2 carbon atoms have been oxidized, that leaves 4 to go in order to account for the 6 six carbons that are oxidized during cellular respiration. • The Citric acid cycle pairs a 2-carbon acetyl-CoA molecule with a 4-carbon oxaloacetate molecule to produce a 6-carbon citrate molecule. However, the 4-carbon oxaloacetate molecule must be continuously regenerated in order to accept more acetyl-CoA molecules. That means that, per citrate molecule from the Citric acid cycle, 2 carbon atoms must be oxidized per turn of the Citric acid cycle. This involves 2 oxidation events. If you account for the fact that the Citric acid cycle must turn twice per glucose molecule, then you know that it is the second oxidation during the Citric acid cycle when glucose becomes completely oxidized to carbon dioxide. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the Version 1
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process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze cellular respiration for when the 6 carbon atoms in glucose become completely oxidized to carbon dioxide. • If you got the correct answer, well done! If you got an incorrect answer, were you able to determine which stages of cellular respiration involved carbon oxidation? Were you able to follow the trail and account for each carbon as it becomes oxidized from glucose? Were you able to determine that the final carbon atoms become oxidized during the Citric acid cycle?
24) D 25) C While all of the oxidation reactions are characterized by the donation of electrons from an organic molecule to an electron acceptor, they are not all decarboxylation reactions, nor do they all involve the generation of NADH. The third oxidation reaction is not a decarboxylation reaction, and involves the generation of FADH2. None of the oxidation reactions directly induce substrate-level phosphorylation of ADP. 26) C
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine why fluoroacetate is an effective pesticide. What type of thinking is required? • You are being asked to take what you know about citrate to isocitrate conversion, and apply your knowledge to determine why fluoroacetate is an effective pesticide. Gather Content What do you already know about cellular respiration and when citrate is converted to isocitrate? What other information is related to the question? •Recall that cellular respiration involves glycolysis, pyruvate oxidation, the Citric acid cycle, and the electron transport chain. During which of these stages is citrate converted to isocitrate by the aconitase enzyme, and which process would be inhibited by the fluoroacetate pesticide? Choose Answer Do you have all necessary information to determine why fluoroacetate is an effective pesticide? • Fluoroacetate prevents conversion of citrate to isocitrate, chemical reactions that only occur during the Citric acid cycle. Citrate is not involved in glycolysis, pyruvate oxidation, or the electron transport chain, which would also preclude anything having to do with ATP synthase. Essentially, fluoroacetate would prevent aerobic respiration in organisms treated with this chemical. Reflect on Process Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to apply what you know about the different stages of cellular respiration to identify which stage involves citrate to isocitrate conversion and use that to determine why fluoroacetate would be an effective pesticide.. • If you got the correct answer, good thinking! If you got an incorrect answer, were you able to recall the different stages of cellular respiration? Were you able to identify which stage involves conversion of citrate to isocitrate? Were you able to infer that inhibition of this reaction would prevent the Citric acid cycle from functioning? 27) D
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine which cellular compartments would be involved with arsenic poisoning, which inhibits pyruvate oxidation and the Citric acid cycle. What type of thinking is required? • You are being asked to use what you know about pyruvate oxidation and the Citric acid cycle, and apply this information to determine where arsenic poisoning would occur within the cell. Gather Content What do you already know about pyruvate oxidation and the Citric acid cycle? What other information is related to the question? • Recall that cellular respiration involves four stages; glycolysis, pyruvate oxidation, the Citric acid cycle, and the electron transport chain. Remember also that glycolysis occurs in the cytoplasm, and the products of glycolysis can be metabolized under either aerobic or anaerobic conditions. If you assume aerobic conditions, then pyruvate oxidation and the Citric acid cycle will be used. Where do pyruvate oxidation and the Citric acid cycle physically occur within cells? Choose Answer Do you have all necessary information to determine where arsenic poisoning would have its greatest impact within the cell? • As we discussed earlier, glycolysis occurs in the cytoplasm, and its products must be imported into the mitochondria to participate in pyruvate oxidation and the Citric acid cycle, particularly when aerobic conditions exist. • Recall mitochondria are divided into seperate spaces, including the outer membrane, the intermembrane space, and the matrix. Version 1
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28) B 29) B 30) D 31) A 32) D
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine the ATP yield for beta-oxidation of a 10-carbon fatty acid. What type of thinking is required? • You are being asked to use what you already know about betaoxidation of fatty acids to determine, or analyze, the ATP yield for a 10carbon fatty acid. Gather Content What do you already know about cellular respiration and betaoxidation of fatty acids? How do these molecules plug into the process of cellular respiration? What other information is related to the question? • Recall that cellular respiration is a process of oxidizing glucose and other organic molecules in order to produce NADH and ultimately the ATP used to power cellular processes. Respiration is comprised of glycolysis, pyruvate oxidation, the Citric acid cycle, and electron transport. • Recall that molecules other than glucose are metabolized for energy in cells; this includes breakdown of fatty acids and glycerol and, in certain circumstances, proteins into amino acids. Each of these molecules plugs into cellular respiration in different places and under different conditions. The process of breaking down fatty acids is called betaoxidation and involves cutting the fatty acid into two carbon fragments (acetyl-CoA) that plug into the Citric acid cycle. Choose Answer Do you have all necessary information to determine the ATP yield Version 1
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from beta-oxidation of a 10-carbon fatty acid? • For each round of the Citric acid cycle, the yield is 10 ATP. To calculate the 10 ATP, remember that 3 NAD+ molecules are produced per turn of the Citric acid cycle. If you multiply that by the 2.5 ATP that can be produced via ATP synthase per NADH molecule, and add that to both the one FADH2 molecule that is also produced during one turn of the Citric acid cycle (which itself produces 1.5 ATP via ATP synthase) and the one ATP produced via substrate-level phosphorylation, then you get something that looks like this: ((3 NADH*2.5 ATP)+(1 FADH2*1.5 ATP)+1 ATP via substrate-level phosphorylation) = 10 ATP. • For each round of beta-oxidation, 1 molecule of ATP is invested, and 1 molecule of NADH and FADH2 is generated. This means that for each round of beta-oxidation, 3 ATP are generated. For a 10-carbon fatty acid, there would be 4 rounds of beta-oxidation to cleave a 10-carbon molecule into 5 2-carbon molecules. Thus, from beta-oxidation there would be a yield of 12 ATP. •Each of these 5 2-carbon acetyl-CoA molecules could then enter the Citric acid cycle; thus the Citric acid cycle will run 5 times for a total yield of 50 ATP. Taken together, the oxidation of a 10-carbon fatty acid would yield 62 ATP. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to remember how beta-oxidation works during cellular respiration and use that to analyze the ATP yield of a 10-carbon fatty acid. • If you got the correct answer, well done! If you got an incorrect answer, were you able to recall how beta-oxidation of fatty acids works? Were you able to correctly calculate how many NADH and FADH2 Version 1
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molecules would be produced from a single 2-carbon fragment from a fatty acid and a turn of the Citric acid cycle? Were you able to determine the total number of ATP from beta-oxidation reactions, ATP synthasegenerated ATP from NADH and FADH2, and ATP made via substratelevel phosphorylation? 33) D 34) B
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine what would happen in a cell that has high citrate levels and low ATP levels. What type of thinking is required? • You are being asked to dissect, or analyze, the cellular outcomes of when citrate levels are high and ATP levels are low. Gather Content What do you already know about the stages of cellular respiration and how they are regulated? What other information is related to the question? • Remember that cellular respiration is comprised of glycolysis, pyruvate conversion, the Citric acid cycle, and electron transport. Recall also that regulating each of these stages involves feedback loops that help the cell to optimize efficient use of resources. • Remember that citrate results from the joining together of acetyl-CoA and oxaloacetate at the beginning of the Citric acid cycle. How are the stages of cellular respiration connected, and what would that mean for the cell if citrate levels are high but ATP levels are low? Choose Answer Do you have all the information needed to determine what would happen to cellular respiration? • Citrate levels help the cell sense when ATP production needs to be increased or decreased. Citrate actually inhibits phosphofructokinase, a key enzyme in the early stages of glycolysis. Thus, you can conclude that glycolysis is probably largely shut down in this question. • However, the fact that ATP levels are low would normally stimulate cellular respiration due to an increased need for ATP. Low levels of Version 1
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ATP will actually stimulate the Citric acid cycle, but because glycolysis is essentially shut down, where can a cell obtain the acetyl-CoA it needs to run the Citric acid cycle? Remember that glucose is not the only fuel that can be metabolized by cells. Fats, and in some cases proteins, can be used as well. • Since no acetyl-CoA will be arriving from glycolysis, and the demand for increased ATP remains, a fuel source other than glucose will need to be used. That fuel source is most likely fatty acid breakdown via betaoxidation. By converting fatty acids into 2-carbon acetyl-CoA molecules, the Citric acid cycle can continue to turn, NADH and FADH2 molecules will still be made, the proton gradient will continue to be established, and ATP synthase will continue to produce ATP. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze what would happen to a cell with high citrate levels and low ATP levels. • If you got the correct answer, nice work! If you got an incorrect answer, were you able to recall the stages of cellular respiration and how they are regulated? Were you able to use information from the question to realize that glycolysis was not working, and therefore could not supply acetyl-CoA to the Citric acid cycle? Were you able to reason that organic molecules other than glucose would have to supply the necessary ATP? 35) C 36) B 37) E 38) C
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine which chemical inhibitor would slow down initial substrate-level phosphorylation. What type of thinking is required? • You are being asked to dissect, or analyze, the effects of each inhibitor on initial substrate-level phosphorylation once glucose has been imported into the cell. Gather Content What do you already know about substrate-level phosphorylation during cellular respiration? What other information is related to the question? • Recall that cellular respiration can produce ATP using two mechanisms: one that uses substrate-level phosphorylation and one that uses oxidative phosphorylation. Remember, oxidative phosphorylation provides the vast majority of ATP that a cell needs, provided oxygen is present. • Each of the three chemicals listed inhibits a different stage of cellular respiration. Which chemical would interfere most with initial substratelevel phosphorylation that could potentially occur right after glucose enters the cell? Choose Answer Do you have all the information needed to determine which inhibitor would have the biggest impact on substrate-level phosphorylation? • The key to answering this question correctly is to realize that when substrate-level phosphorylation occurs during cellular respiration, specifically when substrate-level phosphorylation first occurs after Version 1
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glucose enters the cell. • Remember that substrate-level phosphorylation occurs during glycolysis and the Citric acid cycle. Since the question indicates that the inhibitor should slow initial substrate-level phosphorylation, that means the inhibitor should restrict ATP production during glycolysis. • Of the listed chemicals, TLN-232 is the only inhibitor to restrict glycolysis, and is therefore the correct answer. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze which inhibitor a biochemist should choose to slow down initial substrate-level phosphorylation. • If you got the correct answer, good thinking! If you got an incorrect answer, did you remember that during cellular respiration substrate-level phosphorylation occurs? Were you able to figure out that the most substrate-level phosphorylation would occur following the import of glucose during glycolysis? Were you able to use that information to choose TLH-232 from the list of inhibitors? 39) C 40) C 41) C 42) B 43) D 44) C 45) B
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Clarify Question What is the key concept addressed by the question? • The question essentially asks you to determine the ATP yield for one molecule of pyruvate in a eukaryotic cell. What type of thinking is required? • You are being asked to take what you know about pyruvate and use, or apply, your knowledge to determine how many ATP can be yielded from one pyruvate molecule in a eukaryotic cell. Gather Content What do you already know about ATP yield from pyruvate during cellular respiration? What other information is related to the question? • Recall that cellular respiration is comprised of glycolysis, pyruvate oxidation, the Citric acid cycle, and electron transport. Pyruvate is the main product of glycolysis, but is subsequently metabolized in downstream stages of cellular respiration. • Remember that after glycolysis, pyruvate (a 3-carbon molecule) undergoes an oxidation to form acetyl-CoA (a 2-carbon molecule) and a carbon dioxide molecule. This bond breakage also generates high-energy electrons that are captured by NAD+ to form NADH. Thus, a single pyruvate oxidation reaction produces a single NADH molecule. AcetylCoA then goes on to the Citric acid cycle where it becomes incorporated into citrate and is systematically oxidized to oxaloacetate. Considering all the bonds that are broken during pyruvate oxidation and the Citric acid cycle, how many ATP could potentially be made? Choose Answer Do you have all the information needed to calculate the ATP yield Version 1
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from pyruvate? • Pyruvate oxidation yields 1 NADH and 1 acetyl-CoA. This 1 acetylCoA enters the Citric acid cycle, and one turn generates 3 NADH molecules and 1 FADH2 molecule. That means there are now 4 NADH and 1 FADH2 molecules total. • Recall that each NADH molecule can produce 2.5 ATP molecules and FADH2 can produce 1.5 ATP molecules via ATP synthase and the chemiosmotic proton gradient. So, the total ATP yield would be (4 NADH*2.5 ATP) + (1 FADH2*1.5 ATP) + 1 ATP (substrate-level phosphorylation in Citric acid) = (10 ATP + 1.5 ATP + 1 ATP), which makes a total of 12.5 ATP. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to apply what you know about pyruvate oxidation and the Citric acid cycle to determine the ATP yield from pyruvate. • If you got the correct answer, nice job! If you got an incorrect answer, were you able to identify where NADH and FADH2 molecules were produced during pyruvate oxidation and the Citric acid cycle? Were you able to accurately tally how many ATP molecules were produced from NADH and FADH2? Did you remember to add the single ATP from substrate-level phosphorylation? 46) D 47) D
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine what might happen in patients treated with antiviral drugs. What type of thinking is required? • You are being asked to dissect, or analyze, the possible outcomes of antiviral drug treatment. Gather Content What do you already know about which cellular respiration processes occur in mitochondria? How would a reduction in mitochondria affect the ability of the cell to harvest energy? What other information is related to the question? • Remember that cellular respiration is comprised of glycolysis, pyruvate oxidation, the Citric acid cycle and electron transport. With the exception of glycolysis, all of these processes are related to aerobic respiration, which occurs inside the mitochondria. • If you follow this line of logic, what possible options is a cell left with if it cannot perform pyruvate oxidation, the Citric acid cycle, or electron transport? Choose Answer Do you have all necessary information to determine the outcome on respiration from taking antiviral drugs? • Let’s examine each answer to determine the correct one. We know that oxidative phosphorylation occurs during the electron transport chain and results from aerobic conditions. Considering that the electron transport chain is physically located inside the inner mitochondrial membrane, if the number of mitochondria decreases, so does the ability Version 1
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to conduct oxidative phosphorylation. That can’t be the right answer. • Phosphofructokinase is an enzyme that operates during glycolysis. Even though glycolysis doesn’t involve aerobic conditions, the question indicates that there would be an increase in phosphofructokinase activity. That typically happens when you need to ramp up ATP production, and since there are no mitochondria present due to the antiviral drugs, phosphofructokinase activity is more likely to go down. Likewise, NADH dehydrogenase activity is likely to go down for the same reasons described above. • By process of elimination, that leaves an increase in lactic acid levels. But to make sure this is the correct response let’s examine it further. If you have no mitochondria, aerobic respiration is not possible. Cells still need energy, and so how will they obtain it? By using the same mechanism that is required when cells have no oxygen but still have mitochondria present: lactic acid fermentation. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze the likely outcome for energy metabolism in patients who take antiviral drugs. • If you got the correct answer, nice job! If you got an incorrect answer, were you able to associate the stage of cellular respiration with mitochondrial anatomy? Were you able to eliminate pyruvate oxidation, the Citric acid cycle, and the electron transport chain as possible options because no mitochondria were present? Were you able to infer that the inability of cells exposed to antiviral drugs to aerobically harvest energy would necessitate anaerobic energy harvesting processes like lactic acid Version 1
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fermentation? 48) C
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine the stage of cellular respiration that would be most affected by iron deficiency anemia. What type of thinking is required? • You are being asked to break down, or analyze, the options to determine the likely stage most affected by iron deficiency anemia. Gather Content What do you already know about redox reactions and when they take place during cellular respiration? What other information is related to the question? • You know that the stages of cellular respiration include glycolysis, pyruvate oxidation, the Citric acid cycle, and electron transport. Under anaerobic conditions fermentation can also occur. • The question indicates that cytochromes that are similar to hemoglobin and can participate in oxidation and reduction reactions would be affected if an individual was deficient in iron and developed anemia. Essentially this means iron deficiency will reduce the cell's ability to conduct redox reactions. During which stage of cellular respiration do most redox reactions occur? Choose Answer Do you have all the information needed to determine which stage of cellular respiration would be most affected by iron deficiency? • Determining the right answer for this question is relatively straightforward. Oxidation and reduction reactions happen during glycolysis, but none of them involve anything resembling cytochromes. That answer seems less likely. Version 1
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• Similarly, the Citric acid cycle also contains redox reactions, but again no cytochromes. The same would hold true for fermentation; the absence of cytochromes makes these answers less likely to be correct. • That leaves the electron transport chain as a possible option. We know that redox reactions occur during the electron transport chain; what types of molecules help facilitate those redox reactions? Cytochromes participate in the redox reactions. Therefore, the stage of cellular respiration that would be most affected in someone suffering from iron deficiency anemia would be the electron transport chain. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze each option to determine which stage of cellular respiration would be most affected by someone suffering from iron deficiency anemia. • If you got the correct answer, nice job! If you got an incorrect answer, did you remember which stages of cellular respiration use redox reactions? Did you remember which use cytochromes? Were you able to infer that the electron transport chain would be most affected in individuals suffering from iron deficiency anemia? 49) D
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Clarify Question What is the key concept addressed by the question? • The question asks you to provide a technical explanation as to which cellular respiration process facilitated by cytochrome oxidase would be inhibited by cyanide poisoning. What type of thinking is required? • You are being asked to break down, or analyze, the processes associated with cytochrome oxidase that would be inhibited by cyanide poisoning. Gather Content What do you already know about cellular respiration and cytochrome oxidase? What other information is related to the question? • You know the stages of cellular respiration include glycolysis, pyruvate oxidation, the Citric acid cycle, and electron transport. Cytochromes, particularly cytochrome oxidase, are found in the electron transport chain. Essentially this means cyanide works to inhibit the electron transport chain, but how? What specific processes in the electron transport chain would be most affected by inhibiting cytochrome oxidase? Choose Answer Do you have all the information needed to determine which specific process is directly inhibited by cyanide? • FADH2 does in fact become oxidized, and specifically at complex II of the electron transport chain. However, this option is not connected to cytochrome oxidase. Nor is the reduction of NAD+ related to cytochrome oxidase. We know that proton pumping occurs using Version 1
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multiple complexes in the electron transport chain, so that also seems like an unlikely option. ATP synthesis occurs via ATP synthase, and as long as there is a proton gradient, that enzyme will continue to make ATP. Probably not a suitable choice either. • So what exactly does cytochrome oxidase do? That complex takes the reduced-energy electrons that have been passed through the electron transport chain via the redox reactions and reduces atmospheric oxygen to form water. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze the specific processes associated with the electron transport chain to determine which is involved with cytochrome oxidase and which would be affected by cyanide poisoning. • If you got the correct answer, well done! If you got an incorrect answer, were you able to see that the available answers involved something having to do with the electron transport chain? Were you able to associate cytochrome oxidase with the end of the electron transport chain? Were you able to infer that cyanide poisoning would affect the conversion of atmospheric oxygen into water? 50) B 51) B 52) C 53) D 54) C
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine which function of ATP synthase would be affected if the F1 portion of the protein complex became mutated. What type of thinking is required? • You are being asked to analyze the possible outcomes of mutations in the F1 portion of the ATP synthase complex. Gather Content What do you already know about ATP synthase structure and function? What other information is related to the question? • You likely already know that ATP synthase is the enzyme complex that produces ATP via a proton gradient established by the electron transport chain. What you may not realize is that ATP synthase is actually a molecular machine that is comprised of multiple moving parts, each of which contributes to the overall function of ATP synthase. • How is the ATP synthase complex structured? Located in the inner mitochondrial membrane, ATP synthase is comprised of a domain that transverses the membrane (F0), and another domain that projects into the mitochondrial matrix (F1). Both F0 and F1 domains of ATP synthase contain multiple protein subunits. • Given that information, what outcome do you think would result from a mutation in the F1 domain of ATP synthase? Choose Answer Do you have all necessary information to determine which outcome is most likely from a mutation in the F1 part of ATP synthase? • Considering that the F0 domain of ATP synthase transverses the inner Version 1
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mitochondrial membrane, it is more likely to be involved in proton transport than actual ATP synthesis. Plus, remember that ATP synthase rotates, and it rotates within the membrane, so the function of F1, the other domain, is unlikely to act as the rotor or the proton channel. We already know F1 isn’t involved with insertion into the membrane, so that rules out that answer as well. • That leaves the final option as the catalytic domain that connects inorganic phosphate and ADP to create ATP. And since the question asks what would happen if a mutation in the F1 domain occurred, now you have two lines of argument pointing to it being responsible for ADP to ATP conversion. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze the options to determine which function of the F1 ATP synthase domain would be affected by a mutation. • If you got the correct answer, well done! If you got an incorrect answer, were you aware of the overall structure and function of ATP synthase? Were you able to determine the functions of the F0 and F1 domains? Were you able to infer that mutations in F1 would inhibit the actual process of ATP production? 55) A 56) C 57) D
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine whether or not it is a good idea for your friend to only consume carbohydrates in an attempt to lose weight. What type of thinking is required? • You are being asked to analyze the feasibility of your friend losing weight by only consuming carbohydrates. Gather Content What do you already know about consuming carbohydrates and weight loss? Is excessive carbohydrate intake a good or bad idea? What other information is related to the question? • You hear in the news all the time that we consume too many carbohydrates in our diets. Why the big concern? What harm could it be? Since we know that our bodies metabolize organic fuels through cellular respiration, let’s use what we already know about how cellular respiration works. • Organic fuels are broken down via cellular respiration, including glycolysis, pyruvate oxidation, the Citric acid cycle, and electron transport. These are catabolic processes that convert bonds in organic molecules into energy stored in ATP that cells use to do work. But what happens when we have all the energy our cells need? What do we do with the excess molecules? Choose Answer Do you have all the information needed to determine whether or not excessive consumption of carbohydrates will help or harm your friend? • The metabolism in our cells is a finely-tuned balance of catabolic and Version 1
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anabolic processes. We use catabolic processes to break down organic molecules and harness their energy via cellular respiration. However, when our cells have all the energy (ATP) they need, they tend to save the excess organic molecules for a rainy day, so to speak. This allows the cell to store reserve energy for when the cell needs organic molecules but none are available. • If your friend consumes nothing but carbohydrates, ATP levels will be high and anabolic processes will engage. This will prompt excess acetylCoA to be converted into fatty acids, which is converted into fat. So, consuming nothing but carbohydrates is bad because there is no way for your cells to use it all and it will eventually get stored as fat. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze whether or not your friend could lose weight by consuming nothing but carbohydrates. • If you got the correct answer, well done! If you got an incorrect answer, were you aware that metabolism is a balance of catabolic and anabolic processes that sense cellular ATP levels? Were you able to infer that excess carbohydrate would lead to high ATP levels, prompting the extra acetyl-CoA to be converted into fatty acids? Were you able to draw the conclusion that eating only carbohydrate is a bad idea? 58) A
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Chapter 08 13e MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 1) Where do the carbon atoms in glucose come from? A) Sunlight B) Carbon dioxide C) Water D) NADPH
2) Carbon dioxide and water can combine to form glucose, water and oxygen. What is required for that process to occur? A) Nothing, this is aspontaneous reaction B) Energy from theprocess of cellular respiration C) Light energy fromthe sun D) Mitochondria
3) A protein that has been transported past the outer chloroplast membrane would have to pass how many more membranes to reach the stroma and thylakoid lumen, respectively? A) 1 B) 2 C) 3 D) 4
4) If you tagged organic carbon inside a chloroplast with a fluorescent label, the location most likely to have a high concentration of labeled carbon would be in the A) Stroma B) Thylakoidmembrane C) Between the outerand inner membranes D) Inside thethylakoid
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5)
The splitting of water and the generation of oxygen occur where? A) Photosystem I B) The Krebs Cycle C) The CalvinCycle D) Photosystem II
6)
In order to generate one glucose molecule, the Calvin cycle has to turn how many times? A) 1 B) 2 C) 3 D) 6 E) 12
7) The number of glyceraldehyde-3-phosphate molecules that would be produced from 24 turns of the Calvin cycle would be A) 6 B) 8 C) 4 D) 12 E) 48
8) If the Calvin cycle of a plant exposed to light during the day is suddenly put in the dark, then it: A) cannot run, as it requires light energy directly. B) can still run as long as there is ATP, CO2, and NADPH present. C) runs in a different place in the plant. D) uses a different source of carbon.
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9)
In eukaryotes, photosynthesis takes place inside the_________blank. A) chloroplasts B) mitochondria C) cytoplasm D) Golgi apparatus
10)
Clusters of chlorophyll and accessory pigments are called_________blank. A) the Golgi apparatus B) chloroplasts C) photosystems D) photosynthetic membranes
11) Which plants utilize a specialized carbon fixation enzyme and a unique cell structure to reduce the problems of photorespiration? A) C3 B) C4 C) Desert D) Arctic
12) Plants that show a pattern of stomatal opening and closing that is the reverse of C3 plants are called A) C4. B) Temperate. C) CAM. D) Calvin cycle.
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13) A plant is treated with a chemical that blocks the flow of electrons between photosystem II and photosystem I, such that protons are not transported from the stroma into the thylakoid compartment. What is the effect of this chemical on photosynthesis? A) the increased number of protons will be directly used in the thylakoid to produce glucose B) an increased proton gradient will provide the energy needed to produce ATP from the light reactions C) a decreased proton gradient will cause less ATP to be produced from the light reactions D) the increased proton gradient will be used to make NADPH for the Calvin cycle
14)
In photosynthesis, carbon fixation occurs: A) in photosystemI B) in the electrontransport chain C) in photosystemII D) in the Calvincycle E) duringphotorespiration
15) If the gene encoding the enzyme rubisco is mutated such that it is non-functional, the process that would be affected is the ability to A) make ATP. B) harvest photons. C) fix carbon. D) make O2. E) make NADPH.
16) Most plants incorporate carbon dioxide into sugars by means of a cycle of reactions called the
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A) CAM cycle. B) carbon cycle. C) Calvin cycle. D) Krebs cycle.
17)
Flattened sacs of internal membranes associated with photosynthesis are called A) chloroplasts. B) photosystems. C) the stroma. D) thylakoids. E) cristae.
18)
For photosynthesis in green plants, the electron donor for the light-dependent reaction is A) carbon dioxide. B) oxygen. C) RuBP. D) chlorophyll II. E) water.
19) In the light-independent reactions of photosynthesis, CO2 is added to a five-carbon molecule known as A) cellulose. B) ribose. C) deoxyribose. D) RuBP. E) CAM.
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20) Jan Baptista van Helmont performed an important experiment related to photosynthesis. He weighed a small willow tree and a pot of soil. Jan then planted the tree in the pot. Over the course of five years, he added only water to the pot. At the end of five years, he weighed the tree and found that it had gained 74.4 kg. He weighed the soil, and it was only 57 g less. What do the results of this specific experiment demonstrate about what is needed for a plant to grow and increase its mass? A) All of the food aplant needs to grow comes from the soil B) Plants do not needsoil to grow C) Plants must beable to increase their mass using substances in addition to what is found insoil D) All of the food aplant needs to grow comes from the water E) Plants need oxygento grow
21)
Light consists of units of energy called A) electrons. B) photons. C) calories. D) neutrons. E) pigments.
22)
Visible light has a wavelength range of A) 400-740nanometers. B) 200-800 nanometers. C) 200-400 nanometers. D) 200-740nanometers. E) 0.001-100,000 nanometers.
23)
Molecules that absorb light are called
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A) enzymes. B) electron carriers. C) pigments. D) photosynthesizers. E) absorbers.
24)
Why is eating carrots thought to be useful for enhancing vision?
A) High levels ofchlorophyll in carrots helps with photosynthesis in the eyes. B) High levels ofbeta-carotene can lead to the production of a pigment used in vision. C) High levels ofcarotenoids in carrots can allow vertebrate eyes to perform the darkreactions. D) High levels ofNADPH in carrots can allow vertebrate eyes to perform the light reactions.
25) Chlorophyll b absorbs green wavelengths of light that chlorophyll a cannot absorb. In this respect, chlorophyll b acts as A) an accessory pigment. B) an energizer for photosynthetic bacteria. C) a light absorber in the green light. D) a more efficient pigment.
26) The photosystem channels the excitation energy gathered by absorption of light by any one of the pigment molecules to a specific reaction center chlorophyll, which in turn passes the energy to A) photosystem I. B) photosystem II. C) the primary electron acceptor. D) the secondary electron center. E) cytochrome.
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27)
What is common to both photosystems I and II?
A) Both involve thesplitting of water to donate an electron to the reaction center B) Both involve thegeneration of oxygen C) Both lose anelectron to a primary electron acceptor that passes the electron down anelectron transport chain leading to the generation of ATP D) Both contain areaction center composed of chlorophyll a E) Both are found in the stroma
28) In the photosystem I reaction center, light energy captured by pigment molecules is passed to a special reaction center chlorophyll a called A) P680. B) P700. C) chlorophyll I. D) chlorophyll II. E) retinal.
29)
NADPH is made by A) chemiosmosis. B) glycolysis. C) the Citric acid cycle. D) the Calvincycle. E) the passing ofelectrons from photosystem I to an electron transport chain.
30) In green plants, which photosystem absorbs photons to excite electrons in the reaction center?
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A) Photosystem I B) Photosystem II C) PhotosystemIII D) Photosystem I andII E) Photosystem I, IIand III
31) In the light-independent reactions, when CO2 is added to a molecule of Ribulose 1,5bisphosphate (RuBP) the product is A) citric acid. B) glucose. C) glyceraldehyde-3-phosphate. D) 3-phosphoglycerate. E) pyruvate.
32)
The cyclic carbon fixation reactions are also known as the A) Calvin cycle. B) citric acidcycle. C) tri carboxylic acidcycle.
33)
How many molecules of CO2 are needed to generate one molecule of glucose? A) 2 B) 3 C) 4 D) 5 E) 6
34) A plant researcher wants to construct a synthetic cellulose fiber from 20 glucose molecules. How many molecules of CO2 and glyceraldehyde-3-phosphate are needed to construct the fiber?
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A) 20, 40 B) 120, 60 C) 120, 40 D) 20, 60 E) 120, 120
35)
In which part of the chloroplasts are the Calvin cycle enzymes located? A) stroma B) thylakoids C) grana D) envelope E) cristae
36) The photosynthetic electron transport causes the accumulation of protons in which part of the chloroplast? A) matrix B) stroma C) outer membrane D) internal thylakoidspace
37) A tomato plant is mutated with gamma radiation. A cellular analysis reveals that ATP synthase complexes found in the thylakoid membrane are inserted backward into the membrane. What is the most likely outcome of this error?
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A) A proton gradientwill not be established in the thylakoid space in response to theactivation of photosystem II B) The protongradient in the thylakoid space will not be able to be used to generate ATP C) The thylakoidmembrane will become permeable to protons as a result of this change D) The ATP synthasewill pump protons into the stroma in this orientation E) This change is not likely to have anyeffect on the function of the ATP synthase enzyme with respect to its role inphotosynthesis
38)
What products of light reactions of photosynthesis are used in the Calvin cycle? A) oxygen and protons B) carbon dioxide and water C) ATP and NADPH D) ADP and NADP E) glucose and oxygen
39) If a plant's stomata were always closed, how would this affect the plant's ability to make glucose? A) There would be noeffect on the ability of the plant to make glucose B) Plants would beable to make more sugar than normal C) Plants would makeless sugar than normal
40) Since Rubisco can either fix carbon or oxidize RuBP, what condition will be most favorable for glucose production? A) moderatetemperatures B) hightemperatures C) dry climate D) high oxygenenvironment
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41)
One of the disadvantages of the C4 pathway is that it requires A) more O2. B) more NADPH. C) more light. D) more ATP. E) a much higher temperature.
42)
Which type of plant can utilize the Calvin cycle? A) C3plants B) CAM plants C) C4plants D) C3, C4, and CAMplants
43) Most atmospheric oxygen comes from photosynthesis. From which of the following molecules is the oxygen derived? A) water B) carbon dioxide C) glucose D) chlorophyll a E) chlorophyll b
44) F. F. Blackman performed experiments to investigate the effects of various factors on photosynthesis. In one of his experiments, Blackman found that if light intensity was low, photosynthesis could be accelerated by increasing the amount of light, but not by increasing the temperature or carbon dioxide concentration. What can you conclude from this specific experiment?
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A) Light is importantfor photosynthesis B) Carbon dioxide isimportant for photosynthesis C) High temperaturesare important for photosynthesis D) Photosynthesisgenerates oxygen
45) If chlorophyll a is blocked from absorbing light, what would be the effect on the ability of the plant to do photosynthesis? A) The plant will havean enhanced ability to carry out light-dependent reactions B) The plant will havean enhanced ability to carry out light-independent reactions C) The plant will havea decreased ability to carry out light-dependent reactions D) The plant's ability to carry outphotosynthesis will be unchanged, as one of the accessory pigments can fill infor chlorophyll a
46)
Carotenoids are important to many plants because these pigments are able to A) remove carbon dioxide from the air. B) absorb wavelengths of light that neither chlorophyll a nor b can absorb. C) absorb water so that hydrolysis can be carried out in the chloroplasts. D) capture UV radiation that is harmful to the DNA in the nucleus of plant cells. E) store electrons for use during the "dark" reaction of photosynthesis.
47)
Light-dependent reactions generate A) ATP and NADPH. B) NADP+. C) CO2. D) light. E) glucose.
48)
Fall leaf color on deciduous trees is a result of
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A) the production of more accessory pigments because of the cooler temperatures. B) the reduction in the production of accessory pigments. C) cessation of chlorophyll production, which allows the accessory pigments to be revealed. D) the increased angle of the sun during the fall, which reflects more of the accessory pigments.
49)
In plants, the light-dependent reactions require A) ATP. B) O2. C) NADP+. D) glucose. E) Calvin cycleenzymes.
50) If the Calvin cycle were to be temporarily restricted, the highest concentration of NADPH would likely be in the A) thylakoidspace. B) thylakoidmembrane. C) stroma. D) chloroplast outermembrane.
51)
The Calvin cycle requires all of the following except A) carbon dioxide. B) oxygen. C) ATP. D) NADPH. E) water.
52)
Which color of light chlorophylls absorb has the highest energy?
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A) green B) violet-blue C) red D) yellow-orange
53)
What color of light is not strongly absorbed by chlorophyll? A) green B) violet-blue C) red D) yellow-orange
54)
What are the characteristics of red light, which is absorbed by chlorophylls? A) Its photons havethe shortest wavelength in the visual spectrum B) Its photons havethe highest energy in the visual spectrum C) Its photons havethe longest wavelength in the visual spectrum D) It is notconsidered a part of the visual spectrum
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55)
Copyright© The Mc-Graw-Hill Companies,Inc, Permission Required for reproduction or display. Based on a variety of experiments, it is known that the rate of photosynthesis is highest when wavelengths of light between 400 and 500 nm are used, and when wavelengths around 700 nm are used. What does this indicate about the relative importance of chlorophyll a and b in photosynthesis? A) Reflection oflight by chlorophyll a and b is essential for the process of photosynthesis B) Absorption oflight by chlorophyll a and b is essential for the process of photosynthesis C) Transmission oflight by chlorophyll a and b is essential for the process of photosynthesis D) Chlorophyll a and bare much less important than other pigments in the reflection, absorption andtransmission of light relevant to photosynthesis
56) You are working on a research project that involves a mutational analysis of the light harvesting complex Lhca1, which is an important light harvesting complex found in plants. Your labmate asks where this complex is located. You say it is in the
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A) outer chloroplast membrane B) inner chloroplast membrane C) thylakoid membrane D) stroma E) matrix
57)
The role of the antenna complex in a photosystem is to A) transfer excitedelectrons to the primary electron acceptor. B) generateglucose. C) generate NADPH. D) capture photonsfrom sunlight.
58) Which experimental modification would most effectively help to determine the sequence of reactions and reaction intermediates in the Calvin cycle? A) Exposing the cells to 14CO2 for various time intervals B) Exposing the cells to alternating periods of light and darkness C) Exposing the cells to radiolabeled O2 instead of 14CO2 D) Varying the amount of water the cells are exposed to
59) As a result of the transition from daytime to nighttime, how will the relative concentrations of glyceraldehyde 3-phosphate (G3P) and ribulose 1,5-bisphosphate (RuBP) change in C3 plants? A) The concentrations of G3P and RuBP would remain the same. B) The concentrations of G3P and RuBP would both decrease. C) G3P would increase and RuBP would decrease. D) G3P would decrease and RuBP would increase.
60) During the light-dependent reactions, due to electron transport, the thylakoid space becomes
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A) the site of ATP synthesis. B) the site of NADPH production. C) the site where the Calvin cycle occurs D) more acidic than the stroma.
61) The plant hormone abscisic acid (ABA) is involved in the regulation of photorespiration. Based on this information, ABA likely plays a role in A) the opening and closing of stomata. B) the photoelectric effect. C) cyclic photophosphorylation. D) noncyclic photophosphorylation.
62) If you exposed a C4 plant to 14CO2 in the light, which would be the first organic molecule labeled with 14C? A) oxaloacetate B) malate C) pyruvate D) phosphoenolpyruvate (PEP)
63)
CAM and C4 plants likely grow in what type of environment? A) Cool B) Hot and arid C) High altitude D) In water
64)
In photosynthesis, ATP is made by
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A) chemiosmosis. B) glycolysis. C) the Krebscycle. D) the Calvincycle. E) the passing ofelectrons from photosystem I to an electron transport chain.
65) The ATP generated from cellular respiration is not sufficient to drive the Calvin cycle in plants, even if appropriate levels of NADPH and CO2 are present. Why not? A) Plants do notundergo cellular respiration B) Breaking downsugar to provide the energy needed to synthesize sugar would be a futilecycle C) The Calvin cyclerequires more ATP than can possibly be made from cellular respiration D) Cellular respiration and photosynthesisdo not happen in the same cells in plants
66) If the antenna complex did not exist in a particular plant mesophyll cell, what effect would that have on photosynthesis? A) There would be noexpected effect on photosynthesis B) These cells wouldbe unable to absorb any light energy C) These cells wouldhave a reduced capacity to generate glucose D) These cells wouldbe able to fix more carbon dioxide
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Answer Key Test name: Chap 08_13e_Raven 1) B Through the process of photosynthesis, the carbons in carbon dioxide are fixed and ultimately utilized to generate glucose. Review the equation of photosynthesis in section 8.1. 2) C This describes the process of photosynthesis, which is an endergonic reaction requiring light energy. 3) B
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine how many more chloroplast membranes would be required for a protein to be transported into the thylakoid lumen once it is already past the outer chloroplast membrane What type of thinking is required? • You are being asked to use what you already know about chloroplasts and membranes, and apply that to figure out how many more membranes a protein inside the outer chloroplast membrane would need to pass through to get to the inside of the thylakoid lumen. Gather Content What do you already know about chloroplasts and membranes? What other information is related to the question? • Chloroplasts are the cellular organelle involved in photosynthesis. They are enclosed in multiple membranes, each of which serves to compartmentalize the interior of the chloroplast. • The innermost membrane, called the thylakoid membrane, contains a dense concentration of proteins and chlorophyll molecules that capture sunlight and use it to drive the process of photosynthesis. For example, the thylakoid membrane constituents produce both ATP and NADPH. The thylakoid membrane also maintains an impermeable barrier to protons, the positively charged subatomic particles used to generate the proton gradient needed to produce ATP. Choose Answer Do you have all necessary information to determine what was produced during the plant experiment? Version 1
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• Once you understand chloroplast anatomy it’s fairly straightforward to figure out the answer. Chloroplasts have an outer membrane, and inner membrane, and a thylakoid membrane. In this particular question, the protein has already passed through the outer chloroplast membrane and is in the space just outside of the inner mitochondrial membrane. • So, in order to be transported into the thylakoid lumen, the protein must pass through the inner chloroplast membrane and the thylakoid membrane, bringing the total number of membranes that need to be passed through to two. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to apply what you know about chloroplast anatomy and the number of membranes included in a chloroplast to determine how many more membranes a protein would need to cross in order to get into the thylakoid lumen. • If you got the correct answer, well done! If you got an incorrect answer, were you able to determine the total number of membranes in the chloroplast? Were you able to spatially position the protein in the space between the outer and inner chloroplast membranes? Were you able to count the remaining number of membranes needed to get to the thylakoid lumen? 4) A
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine where in a plant cell a high concentration of labeled carbon would be if you tagged organic carbon. What type of thinking is required? • You are being asked to break down, or analyze, where in a chloroplast you would find a high concentration of labeled organic carbon. Gather Content What do you already know about photosynthesis and where these processes take place in chloroplasts? What other information is related to the question? • Recall that photosynthesis is comprised of the light reactions and the Calvin cycle, both of which occur inside chloroplasts. During the light reactions, which take place in the thylakoid membranes, energy from the sun is captured using molecules like chlorophyll to remove electrons from water, excite them to a higher energy level, and to use redox reactions in order to produce ATP and NADPH.These products are then exported outside the thylakoid to the stroma where the Calvin cycle then uses ATP and NADPH produced during the light reactions to fix inorganic carbon into inorganic from within chloroplasts. • Remember that chloroplasts are comprised of various compartments by the outer and inner chloroplast membranes as well as the thylakoid membrane. Given the information provided in the question, where do you think the most labeled organic carbon might be located? Choose Answer Do you have all necessary information to determine the most likely location? Version 1
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• Recall that the ATP and NADPH produced by light reactions in the thylakoid membrane are exported to the stroma, which is the location of the Calvin cycle and also where inorganic carbon is fixed from the atmosphere into an organic molecular form (e.g carbohydrates). • Because the thylakoid membrane is involved in the light reactions, it is unlikely to be the location for the labeled carbon in this question. Likewise, we know that it can’t be inside the thylakoid because no carbon fixation takes place there. Considering that the stroma is where carbon fixation takes place, it is also the most likely location for labeled carbon in the chloroplast. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze what you know about where in chloroplasts the light reactions and the Calvin cycle take place to determine the most likely location of labeled organic carbon. • If you got the correct answer, good job! If you got an incorrect answer, did you recall that photosynthesis is made up of light reactions and the Calvin cycle, and that only the Calvin cycle is involved with carbon fixation? Did you remember that the light reactions are associated with the thylakoid membranes and therefore could be eliminated as possibilities? Were you able to determine that, because the Calvin cycle is located in the stroma and the purpose of the Calvin cycle is to fix carbon, the stroma must be the most likely location? 5) D Review Section 8.5.
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6) D Review Section 8.6. 7) B
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine how many molecules of glyceraldehyde 3-phosphate would be produced from 24 turns of the Calvin cycle. What type of thinking is required? • You are being asked to calculate, or analyze, the number of glyceraldehyde 3-phosphate produced when the Calvin cycle turns 24 times. Gather Content What do you already know about the Calvin cycle and photosynthesis? What other information is related to the question? • Recall that the biological function of the Calvin cycle is to fix carbon from the atmosphere into organic molecules. The Calvin cycle uses ATP and NADPH produced during the light reactions to fix inorganic carbon into organic carbon from within the stroma of chloroplasts. • Remember that the Calvin cycle is an iterative process, meaning that carbon dioxide is accepted, molecules are transformed, excess carbohydrates are harvested, and new acceptor molecules are regenerated. Given what you know about the Calvin cycle, how many turns are required to produce one glyceraldehyde-3-phosphate molecule? Choose Answer Do you have all the information needed to determine the likely outcome? • Remember that during the Calvin cycle, RuBP binds to six single carbon dioxide molecules and produces a six-carbon molecule that is then converted into two three-carbon molecules of 3-phosphoglycerate. Version 1
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Each of these molecules is subsequently converted into two three-carbon glyceraldehyde 3-phosphate molecules. • The ability of the Calvin cycle to keep operating is dependent on the regeneration of RuBP. Excess glyceraldehyde 3-phosphate molecules are harvested and used to make glucose, whereas other glyceraldehyde 3-phosphate molecules are eventually converted back into RuBP. The trick is knowing how many turns of the Calvin cycle are needed, given the need to regenerate RuBP. • Essentially, one carbon dioxide molecule is incorporated into an organic molecule for every turn of the Calvin cycle. Glyceraldehyde-3phosphate is a 3-carbon molecule, so that means the Calvin cycle will have to turn three times. Since the problem indicates there are 24 turns total, that means 24 turns divided by 3 carbons in each turn of the Calvin cycle for each glyceraldehyde-3-phosphate molecule would equal 8 glyceraldehyde-3-phosphate molecules to be produced. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze the Calvin cycle to determine how many glyceraldehyde 3-phosphate molecules would be produced from 24 turns. • If you got the correct answer, nice job! If you got an incorrect answer, did you recall that the Calvin cycle essentially requires a turn for each carbon that is fixed? Did you remember that each glyceraldehyde-3phosphate molecule contained three carbons? Were you able to calculate the number of glyceraldehyde-3-phosphate molecules given 24 turns of the Calvin cycle? 8) B Version 1
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The Calvin cycle includes the light-independent reactions. Review section 8.6. 9) A 10) C 11) B 12) C 13) C
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine what would happen to a plant that was treated with a chemical that blocks electron flow between photosystems II and I. What type of thinking is required? • You are being asked to use what you know about electron transport and proton gradients and use, or apply, that knowledge to predict what would happen to a plant treated with a chemical that blocks electron transport between photosystems II and I. Gather Content What do you already know about photo systems II and I and electron transport? What other information is related to the question? • The first phase of photosynthesis includes the light reactions, where energy from the sun is captured using chlorophyll molecules localized in Photosystems II and I to remove electrons from water, excite them to a higher energy level, and to use redox reactions and electron transport to eventually produce ATP and NADPH. • Remember that the light reactions, which include photosystems II and I, absorb light, make oxygen by splitting water and produce ATP and NADPH as major products. Electrons focused and amplified by photosystems I and II undergo a series of oxidation-reduction reactions as part of their electron transport chains. What is done with the energy released during electron transport? Choose Answer Do you have the necessary information to solve the problem? • The light reactions of photosynthesis capture photons from sunlight Version 1
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using chlorophyll embedded in photosystems II and I. Under normal conditions, if both photosystems and their electron transport chains are working properly, the plant will harness light energy, split water and excite electrons to higher potential energy, in order to produce ATP and NADPH, with oxygen as a byproduct. • Two electron transport chains occur during the light reactions. Energy given off during the passage of electrons is used to to move protons across the thylakoid membrane in order to generate the proton gradient used to produce ATP via ATP synthase. Therefore, if the electron transport between photosystem II and I were to be disrupted by the chemical, the direct effect would be a decreased proton gradient that would lead to a decrease of ATP production. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to apply what you know about electron transport and proton gradients to determine what happens when the chemical treatment of a plant disrupts electron transport between photosystem II and I. • If you got a correct answer, nice job! If you got an incorrect answer, did you recall that the light reactions rely on redox reactions during electron transport? Did you remember that photosystems and electron transport work together during the light reactions to produce a proton gradient? Were you able to determine that a chemical that blocks electron transport would decrease the proton gradient and reduce ATP production? 14) D Review section 8.6 Version 1
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15) C
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine which photosynthetic process would be affected by a rubisco enzyme loss-of-function mutation. What type of thinking is required? • You are being asked to dissect, or analyze, the photosynthetic process most likely to be affected by a rubisco enzyme mutation that destroys its function. Gather Content What do you already know about photosynthesis processes? What other information is related to the question? • The first phase of photosynthesis includes the light reactions, where energy from the sun is captured using chlorophyll molecules localized in Photosystems I and II to remove electrons from water, excite them to a higher energy level, and to use redox reactions to produce ATP and NADPH. • Remember that the light reactions, which include photosystems I and II, absorb light, make oxygen by splitting water and produce ATP and NADPH as major products. Electrons focused and amplified by photosystems I and II undergo a series of oxidation-reduction reactions as part of their electron transport chains. The Calvin cycle then takes products from the light reactions and uses them to make carbohydrates. During what photosynthetic process is rubisco active? Choose Answer Do you have the necessary information to dissect the problem? • The light reactions of photosynthesis capture photons from sunlight using chlorophyll embedded in photosystems I and II and use that Version 1
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energy to establish a proton gradient, produce ATP, and reduce NADP+ to NADPH. These products are then used to fix inorganic carbon into organic form during the Calvin cycle. • The key enzyme involved in carbon fixation is rubisco. Since carbon fixation occurs during the Calvin cycle, no answers that involve products from the light reactions are plausible. That means making ATP, harvesting photons, making oxygen, and producing NADPH are infeasible answers. Therefore, the likely outcome of a rubisco enzyme mutation would be an inability to fix carbon and produce carbohydrates. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze the possible photosynthetic effect of a mutation in the rubisco enzyme. • If you got a correct answer, well done! If you got an incorrect answer, did you recall that carbon fixation occurs during the Calvin cycle? Did you remember that the key enzyme that fixes carbon is rubisco? Were you able to infer that mutations in rubisco would affect carbon fixation? 16) C 17) D 18) E 19) D 20) C Because the plant increased its mass to a greater extent than the soil mass was depleted, this suggests that the plant can increase its mass using substances other than what is found in the soil. Review section 8.2. 21) B 22) A Version 1
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23) C 24) B See section 8.3. In no case can vertebrates perform the reactions of photosynthesis within their own cells. 25) A 26) C 27) D
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine what photosystems I and II have in common. What type of thinking is required? • You are being asked to break down, or analyze, each photosystem and compare their features to determine what they have in common. Gather Content What do you already know about the role that photosystems I and II in photosynthesis? What other information is related to the question? • Photosynthesis is comprised of the light reactions, which produces ATP, NADPH, and oxygen; and the Calvin cycle, which produces organic molecules from inorganic carbon dioxide. The first phase of photosynthesis includes the light reactions, where energy from the sun is captured using concentrated chlorophyll clusters organized in photosystems to remove electrons from water, excite them to a higher energy level, and to use redox reactions in order to eventually produce ATP and NADPH. • Photosystems I and II are key to the function of the light reactions. Each photosystem is comprised of multiple chlorophyll molecules that have specialized functions that serve to focus and amplify high-energy electrons and bring them to a reaction center. Comparing these photosystem features, how do they differ, and what do they have in common? Choose Answer Do you have all the information needed to make a comparison? • Chlorophyll molecules arranged in a cluster absorb photons from the Version 1
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sun and elevate the potential energy of an electron stripped from a water molecule. During this process the high-energy electron is passed to the photosystem reaction center and eventually on to an electron acceptor that begins the downstream process of electron transport, establishment of a proton gradient, and ATP production. • Light reactions, where photosystems operate, happen in the thylakoid membrane and not the stroma. Splitting water occurs early on in the light reactions, and photosystem II is the complex that serves this function. If you recall, oxygen is a byproduct of water splitting, so anything having to do with the splitting of water or oxygen production can’t be associated with photosystem I, only photosystem II. So these are differences, not similarities. We also know that only photosystem II operates the proton pump needed to generate ATP. Yet again, another difference between the two photosystems. • That leaves the only possible commonality between the two photosystems the reaction center composed of chlorophyll a. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze photosystems I and II to determine what they have in common. • If you got a correct answer, well done! If you got an incorrect answer, did you recall that the light reactions in photosynthesis rely on photosystems? Did you remember that photosystems contain reaction centers? Were you able to eliminate functions that are specific to one photosystem or the other and use that to compare functions they have in common? 28) B Version 1
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29) E Review Section 8.5. The electron transport chain that follows photosystem I is directly responsible for generating NADPH. 30) D Review Section 8.5. 31) D 32) A 33) E Glucose is C6H12O6. Since there are 6 carbons in this molecule, 6 CO2 molecules are needed to make one molecule of glucose. 34) C
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Clarify Question What is the key concept addressed by the question? • The question asks you to decipher how many molecules of carbon dioxide and glyceraldehyde-3-phosphate are needed to construct a cellulose fiber comprised of 20 glucose molecules. What type of thinking is required? • You are being asked to dissect, or analyze, a synthetic cellulose fiber that is 20 glucose molecules long to determine how many molecules of carbon dioxide and glyceraldehyde-3-phosphate are needed. Gather Content What do you already know about the Calvin cycle, carbon dioxide, and glyceraldehyde-3-phosphate? What other information is related to the question? • Recall that the biological function of the Calvin cycle is to fix carbon from the atmosphere into an organic molecule. The Calvin cycle uses ATP and NADPH produced during the light reactions to fix inorganic carbon into an organic form within the stroma of chloroplasts. One turn of the Calvin cycle is required for each carbon dioxide molecule that is fixed by the enzyme rubisco. • Remember that the Calvin cycle is an iterative process, meaning that carbon dioxide is accepted, molecules are transformed, and excess carbohydrate in the form of glyceraldehyde-3-phosphate is harvested. How many carbons make up glyceraldehyde-3-phosphate, and how many turns of the Calvin cycle would be required to produce this molecule? Choose Answer Do you have all the information needed to determine the likely Version 1
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outcome? • Remember that, during the Calvin cycle, RuBP binds to a single carbon dioxide molecule and produces a six-carbon molecule that is then converted into two three-carbon molecules of 3-phosphoglycerate. Each of these molecules is subsequently converted into two three-carbon glyceraldehyde 3-phosphate molecules. A complex series of chemical reactions is needed to regenerate RuBP; however excess glyceraldehyde 3-phosphate molecules can be harvested and used to make a six-carbon glucose molecule. • If you understand how many carbons make up glyceraldehyde-3phosphate and glucose, the rest should be fairly straightforward math. A synthetic cellulose fiber that contains 20 glucose molecules would contain six times that number in carbon atoms because glucose has six carbons in its structure, meaning 120 molecules of carbon dioxide would be required to make the fiber. On the other hand, glyceraldehyde-3phosphate contains three carbons and so would require one third the total number of carbon atoms, which in this case is 40. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze the Calvin cycle to determine how many carbon dioxide and glyceraldehyde 3-phosphate molecules would be needed to make a synthetic cellulose fiber that contained 20 glucose molecules. • If you got the correct answer, well done! If you got an incorrect answer, did you recall how many carbon dioxide molecules the Calvin cycle can fix per turn? Did you remember how many carbon atoms are in a glyceraldehyde 3-phosphate molecule, and how many of these are Version 1
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required to make one glucose molecule? Were you able to calculate the total number of carbon dioxide and glyceraldehyde-3-phosphate molecules based on this information? 35) A 36) D 37) B
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Clarify Question What is the key concept addressed by the question? • The question asks you to consider what would happen to a tomato plant that was mutated with gamma radiation such that ATP synthase is inserted in the thylakoid membrane in a reverse orientation. What type of thinking is required? • You are being asked to consider the different outcomes of radiationbased mutation on a tomato plant and use that to weigh and judge, or evaluate, the most likely outcome if ATP synthase had a reverse orientation. Gather Content What do you already know about ATP synthase and thylakoid membranes? What other information is related to the question? • The light reactions are the first phase of photosynthesis, where energy from the sun is used to split water, excite electrons to a higher energy level, and use redox reactions and electron transport in order to establish a proton gradient across the thylakoid membrane. • The thylakoid membrane serves to establish a proton gradient that is used by ATP synthase to produce ATP. The orientation of ATP synthase is crucial to its ability to harness the gradient. In a normally functioning tomato plant with non-mutated chloroplasts and ATP synthase enzymes, where is the proton concentration highest and lowest across the thylakoid membrane? Choose Answer Do you have all the information needed to solve the problem? • Recall that energy harnessed from redox passage of electrons during the light reactions is used to establish a proton gradient across the Version 1
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thylakoid membrane. The movement of protons down their concentration gradient through ATP synthase provides the ATP needed for the Calvin cycle, which takes place in the stroma. • If ATP synthase were inserted backward into the membrane, that would mean that the portion of the enzyme through which protons enter to flow down their concentration gradient would be facing towards the stroma, while the portion of the enzyme that synthesizes ATP would be facing into the thylakoid space. As a result, the buildup of protons in the thylakoid space, in response to photosystem II, could not enter the ATP synthase enzyme and be used to generate ATP. This proton gradient would still be generated, as photo system II and its downstream electron transport chain are still intact. • The permeability of the thylakoid membrane is not likely to be changed by the insertion of the ATP synthase in the wrong orientation. While ATP synthase can be used to pump protons across a membrane, as an active transport process, in the new orientation, ATP synthase would only be able to pump protons into the thylakoid space. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to evaluate possible outcomes for radiation induced mutation in a tomato plant that causes ATP synthase to be inserted backward into the thylakoid membrane. • If you got a correct answer, nice job! If you got an incorrect answer, did you recall that electron transport during the light reactions produces a proton gradient? Did you remember that ATP synthase produces ATP based on the proton gradient? Were you able to determine that a Version 1
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mutation that reorients ATP synthase backward would not be able to harness the proton gradient to produce ATP? 38) C 39) C
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Clarify Question What is the key concept addressed by the question? • The question asks you to decipher what would happen to glucose production if a plant always had its stomata closed. What type of thinking is required? • You are being asked to dissect, or analyze, how a plant’s ability to produce glucose would be affected with closed stomata. Gather Content What do you already know about how stomata and gas exchange in plants? What other information is related to the question? • Recall that plants import carbon dioxide and export oxygen due to concentration differences on both the inside and outside the plant. For example, oxygen is in its highest concentration inside the plant, and because the concentration of oxygen is lower in the atmosphere, diffuses from inside to outside the plant. Conversely, carbon dioxide is in higher concentration outside the plant and thus diffuses into the plant where the concentration of carbon dioxide is lower. • The anatomical gateways a plant uses to regulate gas exchange are the stomata that are located primarily in leaves. Analogous to a human nose or mouth, stomata can open or close, depending on environmental suitability and photosynthetic need of the plant. Considering the importance of carbon dioxide in photosynthesis, what do you think would happen to a plant whose stomata are permanently closed? Choose Answer Do you have all the information needed to determine what would happen to the plant with closed stomata? • Remember that photosynthesis is comprised of the light reactions in Version 1
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the Calvin cycle. The Calvin cycle in particular requires carbon dioxide in order to fix carbon and produce carbohydrates. • If a plant's stomata were always closed, it would not be able to take in carbon dioxide from the environment. As a result, the ability of that plant to make glucose would be significantly decreased. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze what would happen to a plant’s capacity to produce glucose if its stomata were closed. • If you got the correct answer, well done! If you got an incorrect answer, did you remember that oxygen and carbon dioxide gases move from high to low concentration? Did you remember that plant stomata regulate gas exchange? Were you able to infer that preventing carbon dioxide from entering the plant would restrict the Calvin cycle and therefore sugar production? 40) A
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine the most favorable conditions for glucose production given that rubisco can either fix carbon or oxidize RuBP. What type of thinking is required? • You are being asked to weigh and judge, or evaluate, the different environmental conditions to determine which would most favorably produce glucose. Gather Content What do you already know about RuBP, rubisco, and the Calvin cycle? What other information is related to the question? • Recall that plants are evolutionarily adapted to particular climates and environments and respond differently depending on whether the environment is hot, dry, or humid. Part of a plant’s ability to physiologically adapt to an environment has to do with how it metabolizes carbon, and what happens to the machinery that fixes carbon when conditions are not optimal. • Remember that the molecule that accepts atmospheric carbon during the Calvin cycle is ribulose-1,5-bisphosphate, or RuBP. Remember also that the key enzyme involved in carbon fixation during the Calvin cycle is RuBP carboxylase/oxygenase, or rubisco. This enzyme is key in taking inorganic carbon dioxide from the air and fixing it in an organic molecule, although under less ideal conditions can oxidize RuBP. Considering the different environmental conditions indicated, how might rubisco’s function change? Choose Answer Version 1
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Do you have all the information needed to determine the most favorable condition for glucose production? • Let’s take each option and consider it individually to determine the most correct answer. If environmental conditions are hot or dry, the plant will close its stomata in order to prevent water loss, thereby restricting carbon dioxide diffusion into the leaves. Under those conditions, if light were still available, the light reactions would still occur and oxygen levels would increase. • Anything that increases the relative level of oxygen will not be favorable for glucose production, as rubisco will favor oxidizing RuBP instead of fixing carbon. As a result, anything that leads to the closing of stomata, or changes the overall level of oxygen will be unfavorable. • Conversely, moderate temperatures allow stomata to remain open, and thus allow carbon dioxide to enter the leaves. This is why moderate temperatures are the most favorable condition for glucose production. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to evaluate several environmental conditions for which would be most favorable for glucose production, considering that rubisco can fix carbon or oxidize RuBP. • If you got the correct answer, excellent! If you got an incorrect answer, were you able to determine what would happen to stomata and rubisco function under high temperatures and dry climate? Were you able to figure out that oxygen levels would increase if stomata were closed during the day? Were you able to infer moderate temperatures would be preferable to any of the other conditions? Version 1
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41) D 42) D All of these plants can do the Calvin cycle. The difference between them is how they fix carbon. 43) A 44) A
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Clarify Question What is the key concept addressed by the question? • The question asks you to draw a conclusion about photosynthesis based on Blackman’s experimental results. What type of thinking is required? • You are being asked to weigh and judge, or evaluate, Blackman’s experimental results and use that information to draw a conclusion. Gather Content What do you already know about photosynthesis? What other information is related to the question? • Recall that photosynthesis is a process of creating organic molecules from inorganic carbon sources using light energy. Photosynthesis is comprised of the light reactions and the Calvin cycle. Light and carbon dioxide are inputs of photosynthesis and oxygen and carbohydrate (among other molecules) are outputs of photosynthesis. • The observation that photosynthesis could be accelerated by increasing the amount of light but not by increasing temperature or carbon dioxide concentration is telling. How is this observation important to drawing a conclusion about photosynthesis in this experiment? Choose Answer Do you have all the information needed to draw a supported conclusion? • Let’s unpack each option and see how well it is supported by experimental observations. We know that plants need to carbon dioxide, but increasing carbon dioxide did not increase photosynthesis in this experiment. Likewise, increasing temperature did not increase Version 1
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photosynthesis either. And while we know that photosynthesis generates oxygen, there is no connection between experimental observations and that outcome, so that is not a supported conclusion. • The process of elimination leaves us with light being important for photosynthesis as the logical conclusion, but why else would that make sense? Experimental observations showed that as light increased, so did photosynthesis. The fact that increased carbon dioxide did not increase photosynthesis would support the conclusion that light is essential. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to evaluate Blackman’s experimental results and draw an accurate conclusion based on those observations. • If you got the correct answer, good thinking! If you got an incorrect answer, were you able to weigh Blackman’s observations and correlate that with a conclusion? Were you able to eliminate carbon dioxide and high temperatures as options based on the observations? 45) C
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine what would happen to photosynthesis if chlorophyll a was blocked from absorbing light. What type of thinking is required? • You are being asked to use what you know about photosynthetic pigments and use, or apply, this knowledge to determine what would happen to a plant when chlorophyll a was blocked from absorbing light. Gather Content What do you already know about the role of pigments during photosynthesis? What other information is related to the question? • Photosynthesis is comprised of the light reactions, which produces ATP, NADPH, and oxygen and the Calvin cycle, which produces organic molecules from inorganic carbon dioxide. The first phase of photosynthesis includes the light reactions, where energy from the sun is captured using concentrated chlorophyll clusters organized in photosystems to remove electrons from water, excite them to a higher energy level, and to use redox reactions in order to eventually produce ATP and NADPH. • Each of the two photosystems in plants is comprised of multiple chlorophyll molecules, one of which is chlorophyll a. If you blocked chlorophyll a, what you think would happen to the plants ability to photosynthesize? Choose Answer Do you have all the information needed to determine what would happen? • Let’s see if we can eliminate some possible answers. First, we know Version 1
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that blocking one of the main light harvesting molecules will have an impact on photosynthesis, so the plants ability to photosynthesize will certainly be changed. Second, light independent reactions like the Calvin cycle don’t depend on light directly, so all other things being equal that would also not be a correct choice. The question then becomes about whether blocking chlorophyll a will enhance or decrease light dependent reactions. • Let’s consider now what makes up a photosystem. Chlorophyll a molecules arranged in a cluster absorb photons from the sun and elevate the potential energy of an electron stripped from a water molecule. During this process the high-energy electron is passed to the photosystem reaction center and eventually on to an electron acceptor that begins the downstream process of electron transport, establishment of a proton gradient, and ATP production. Therefore, if you block chlorophyll a from absorbing light, fewer of those processes will take place, and the plants ability to photosynthesize will suffer. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to apply what you know about chlorophyll a and its role in photosynthesis. • If you got a correct answer, good job! If you got an incorrect answer, did you recall that a plant’s ability to photosynthesize relies on pigments like chlorophyll a? Did you remember that chlorophyll a molecules are a key component of photosystems, and that photosystems are core to the light reactions ability to function? Were you able to infer that blocking chlorophyll a would then decrease photosynthesis? 46) B Version 1
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47) A 48) C 49) C The light-dependent reactions generate ATP and oxygen. Calvin cycle enzymes are required for the light-independent reactions. Glucose is the ultimate product of photosynthesis. 50) C
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Clarify Question What is the key concept addressed by the question? • The question asks you to decipher where the highest concentration of NADPH would be located if the Calvin cycle were to be temporarily restricted. What type of thinking is required? • You are being asked to break down, or analyze, photosynthetic processes and where they occur to determine where the highest concentration of NADPH would be located following restriction of the Calvin cycle. Gather Content What do you already know about NADPH, where it is produced, and where it is used? What other information is related to the question? • Recall that photosynthesis is comprised of the light reactions, which produces ATP, NADPH, and oxygen; and the Calvin cycle, which produces organic molecules from inorganic carbon dioxide. The first phase of photosynthesis includes the light reactions, where energy from the sun is captured using molecules like chlorophyll to remove electrons from water, excite them to a higher energy level, and to use redox reactions to produce ATP and NADPH. • The second phase of photosynthesis includes the Calvin cycle, which uses the ATP and NADPH products of the light reactions to fix inorganic carbon into an organic form within chloroplasts. If the Calvin cycle were to be restricted, what would happen to the NADPH concentration as a result? Choose Answer Do you have all necessary information to determine what type of Version 1
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reaction is taking place? • The light reactions of photosynthesis, which occurs in the thylakoid membrane, produce ATP and NADPH. While both of these molecules are important to the Calvin cycle, if the Calvin cycle were restricted they would still continue to be produced because there is no restriction in light. • Since NADPH is required to help drive the Calvin cycle, and this occurs in the stroma, a restriction of the Calvin cycle would allow NADPH to accumulate, leading to a high concentration. This leads one to conclude the stroma is where the highest concentration of NADPH would be located. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to apply what you know about chloroplast anatomy and NADPH production to determine where the highest concentration of NADPH would be located if the Calvin cycle were to be temporarily restricted. • If you got a correct answer, excellent! If you got an incorrect answer, did you recall that the light reactions produce the NADPH used by the Calvin cycle? Did you recall that the light reactions occur in the thylakoid membrane and involve the thylakoid space? Were you able to infer restriction of the Calvin cycle would allow NADPH to accumulate in the stroma where it is normally used? 51) B 52) B
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Chlorophylls absorb violet-blue, blue, orange-red, and red light. Of these, violet-blue light has the shortest wavelength and thus the highest energy. 53) A 54) C Review Figure 8.4. 55) B
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine the relative importance of chlorophyll a and b in photosynthesis. What type of thinking is required? • You are being asked to decipher, or analyze, data from the graph to determine the relative importance of chlorophylls a and b in photosynthesis. Gather Content What do you already know about the role of pigments during photosynthesis? What other information is related to the question? • The first phase of photosynthesis includes the light reactions, where energy from the sun is captured using concentrated chlorophyll clusters organized in photosystems to remove electrons from water, excite them to a higher energy level; then redox reactions are used to eventually produce ATP and NADPH. • Each type of chlorophyll contributes differently to the overall ability of the plant to absorb solar energy and fix carbon. Given the data in the graph, what is the relative importance of chlorophylls a and b? Choose Answer Do you have all the information needed to analyze the graph and answer the question? • Chlorophylls are the main light harvesting molecules that plants use to photosynthesize. This graph shows three types of pigment molecules; carotenoids, chlorophyll a, and chlorophyll b. • Let’s consider the graph itself for a moment. The X axis shows the wavelength of light whereas the Y axis shows the amount of light that can be absorbed. Considering that photosynthesis is about absorbing light, it makes sense to eliminate answers that talk about reflection or transmission of light. Using the location and size of their absorption peaks, it is clear from reading the graph that chlorophylls a and b are important, so we can also eliminate the answer that indicates they are less important. • Based on the data presented in the graph, and process of eliminating incorrect answers, the correct response is 'chlorophyll a and b are essential for photosynthesis'. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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• Answering this question correctly depended on your ability to analyze the graph to determine the relative importance of chlorophylls a and b. • If you got a correct answer, well done! If you got an incorrect answer, did you recall that a plant’s ability to photosynthesize relies on pigments like chlorophyll? Did you remember that there are different types of chlorophyll molecules? Were you able to decipher data from the graph that shows the importance of chlorophylls a and b for light absorption and therefore photosynthesis?
56) C
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine where the light harvesting complex Lhca1 is located so you can communicate this to your lab mate who is performing a mutational analysis. What type of thinking is required? • You are being asked to take what you know about photosystems and light harvesting complexes and use, or apply, your knowledge to answer your labmate’s question. Gather Content What do you already know about how light harvesting occurs in photosystems during photosynthesis? What other information is related to the question? • Photosynthesis is comprised of the light reactions, which produce ATP, NADPH, and oxygen; and the Calvin cycle, which uses products from the light reactions to construct organic molecules from inorganic carbon dioxide. The light reactions capture and concentrate solar energy from chlorophyll molecules clustered into light harvesting complexes like Lhca1. Can you recall where the light reactions and the Calvin cycle take place within chloroplasts? Choose Answer Do you have all the information needed to provide an explanation? • During the light reactions, chlorophyll molecules arranged in a cluster, or light harvesting complex, absorb photons from the sun and elevate the potential energy of an electron stripped from a water molecule. The light reactions take place in the thylakoid membrane, which is the location of the photosystems and therefore complex Lhca1. The other answers can Version 1
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be eliminated because neither the outer nor the inner chloroplast membranes contain light harvesting molecules, and the stroma is where the Calvin cycle takes place, not the light reactions. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to apply what you know about the light reactions, photosystems, and light harvesting clusters of pigment molecules like Lhca1 to provide an explanation to your labmate. • If you got a correct answer, nice job! If you got an incorrect answer, did you recall that the light reactions in photosynthesis rely on photosystems? Did you remember that photosystems contain reaction centers? Did you remember that the light reactions occur in the thylakoid membrane, and therefore the light harvesting complex Lhca1 must be located there as well? 57) D 58) A
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine which experimental modification would most effectively help determine reactions and intermediates in the Calvin cycle. What type of thinking is required? • You are being asked to weigh and judge, or evaluate, the different experimental modifications to determine which approach would be most effective for investigating the Calvin cycle. Gather Content How would you begin to narrow down the experimental options? What key molecules could you focus on considering the investigation is about the Calvin cycle? • Recall that photosynthesis is comprised of the light reactions, which produces ATP, NADPH, and oxygen; and the Calvin cycle, which produces organic molecules from inorganic carbon dioxide. • The first phase of photosynthesis includes the light reactions, where energy from the sun is captured using molecules like chlorophyll to remove electrons from water, excite them to a higher energy level; and then the plant uses redox reactions to produce ATP and NADPH. The second phase of photosynthesis includes the Calvin cycle, which uses the ATP and NADPH products of the light reactions to fix inorganic carbon into an organic form within chloroplasts. • Considering what you know about the Calvin cycle, which experimental options make the most sense? Choose Answer Do you have all the information needed to determine which Version 1
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experimental approach would be most effective? • Since this question focuses on the Calvin cycle and not the light reactions, exposing the cells to alternating periods of light and darkness is unlikely to affect the Calvin cycle directly. Likewise, molecules associated with the light reactions like water and oxygen are probably less useful as well. That leaves using a carbon dioxide-based approach as the most effective for determining reactions and reaction intermediates in the Calvin cycle. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to apply what you know about key molecules in both the light reactions and the Calvin cycle to determine which experimental modification would most effectively determine reactions and intermediates in the Calvin cycle. • If you got a correct answer, well done! If you got an incorrect answer, were you able to identify the key molecules in each answer? Were you able to use that information to systematically eliminate options that were associated with the light reactions and not the Calvin cycle? Were you able to conclude that the carbon dioxide based experimental modification would be most suitable for investigating the Calvin cycle? 59) C
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine how the relative concentrations of G3P and RuBP change as C3 plants transition from day to night. What type of thinking is required? • You are being asked to dissect, or analyze, C3 plant daytime to nighttime transition to determine how G3P and RuBP concentrations will change. Gather Content What do you already know about G3P and RuBP? How does C3 plant photosynthesis change from day to night? • Glyceraldehyde-3-phosphate is one of two 3-carbon molecules produced at the beginning of the Calvin cycle. Initially, a single carbon dioxide molecule will be bound to RuBP, a 5-carbon molecule, by the enzyme rubisco; the resulting six-carbon molecule will split into two 3carbon molecules of G3P. • Under daylight conditions, the light reactions of photosynthesis will produce ATP and NADPH, which are then used by the Calvin cycle to fix carbon dioxide. Recall that producing each 3-carbon G3P molecule requires three turns of the Calvin cycle. Choose Answer Do you have all the information needed to determine which molecule would be affected most? • First let’s consider what happens to G3P and RuBP in the Calvin cycle during the day when there is plenty of light available. RuBP, a 5-carbon molecule, accepts a single carbon dioxide from the atmosphere, • There are three phases to the Calvin cycle. During the first phase, Version 1
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carbon fixation, RuBP binds to a carbon dioxide molecule and forms a six carbon molecule that is then converted into two molecules of 3phosphoglycerate. The next phase of the Calvin cycle, reduction, serves to convert 3-phosphoglycerate to glyceraldehyde-3-phosphate. The final phase of the Calvin cycle, regeneration, requires RuBP to be remade; otherwise the mechanism to accept further carbon dioxide does not exist. • Regeneration of RuBP is heavily dependent on G3P, since it takes 5 G3P molecules to produce three RuBP molecules. So how can we use this information to answer the question? • During the night, neither the light reactions nor the Calvin cycle operate. The ATP and NADPH required to convert G3P into RuBP has decreased; therefore the level of RuBP would have to go down. Since multiple G3P molecules are needed to regenerate RuBP, the concentration of G3P would necessarily have to go up as a result. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze C3 plant daytime to nighttime transition for changes in G3P and RuBP concentrations. • If you got the correct answer, good job! If you got an incorrect answer, did you recall the different phases of the Calvin cycle? Were you able to identify the key molecules involved? Were you able to determine how G3P and RuBP concentration would change? 60) D
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine what happens to the thylakoid space due to electron transport. What type of thinking is required? • You are being asked to use, or apply, what you know about the light reactions and electron transport to determine what happens to the thylakoid space. Gather Content What do you already know about thylakoid membranes and proton gradients? What other information is related to the question? • First, let’s orient you to chloroplast membrane structure and function. The innermost membrane in the chloroplast is the thylakoid membrane, and it is important because it contains the proteins used to produce both ATP and NADPH. The thylakoid membrane maintains an impermeable barrier to protons, the positively charged subatomic particles used to generate the proton gradient needed to produce ATP. • Remember that a biological outcome of photosynthesis is to produce carbohydrate. In order to do that, plants and similarly photosynthesizing organisms use the light reactions, where energy from the sun is captured using chlorophyll molecules localized in photosystems I and II to strip electrons from water, excite them to a higher energy level, and use redox reactions in order to produce ATP and NADPH via proton gradients. The reason why thylakoid membranes are important is because this is where the protein complexes used to capture sunlight and produce ATP and NADPH are located, and it is the barrier that establishes and maintains the proton gradient. • Remember also that the ATP and NADPH produced from the light Version 1
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reactions are used by the Calvin cycle, located in the chloroplast stroma. Given this information, what happens to the thylakoid space? Choose Answer Do you have the information needed to make a determination? • Under normal conditions, if both photosystems and their electron transport chains are working properly, a plant will harness light energy, split water and excite electrons to higher potential energy, and produce ATP and NADPH, based partly on the integrity of thylakoid membranes. The light reactions rely on the integrity of the thylakoid membrane, which establishes and maintains separation of protons, to allow an electrochemical gradient to form. This gradient is crucial to ATP production, without which the Calvin cycle that produces sugar cannot function. • The electrochemical gradient formed across the thylakoid membrane represents a difference in proton concentration. Another way to look at changes in proton concentration is pH. Thus, any difference in proton concentration across a membrane also represents a pH change. In this case, since there are more protons on the lumen side of the thylakoid membrane than the stroma side, the thylakoid space is in fact more acidic than the stroma. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to apply what you know about the light reactions and electron transport to determine what happens to the thylakoid space. Version 1
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• If you got a correct answer, nice job! If you got an incorrect answer, did you recall where the light reactions and the Calvin cycle physically take place within the chloroplast? Did you remember that the light reactions and electron transport produce ATP via a proton gradient across the thylakoid membrane? Were you able to correlate the difference in proton concentration across the thylakoid membrane with a pH difference as well? 61) A
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine the role of ABA based on its role in photorespiration during photosynthesis. What type of thinking is required? • You are being asked to dissect, or analyze, how ABA might help to regulate photo respiration in plants. Gather Content What do you already know about photorespiration in photosynthesis? What other information is related to the question? • Recall that the key enzyme during Calvin cycle carbon fixation is rubisco. This enzyme is essential in taking inorganic carbon dioxide from the air and fixing it in an organic molecule, and under those conditions works as a carboxylase enzyme. However, rubisco also operates as an oxygenase enzyme. Rubisco carboxylase is associated with normal Calvin cycle production of G3P and regeneration of RuBP, whereas rubisco oxygenase activity prevents RuBP from proceeding in the Calvin cycle. • Given the potentially adverse effects of photorespiration, how can ABA be used to regulate this process? Choose Answer Do you have all the information needed to determine what processes ABA regulates in plants? • Although the answers seem a little complicated, the correct answer is fairly straightforward. If you want to minimize rubisco oxygenase activity and maximize carboxylase activity, what environmental factors would you change in order to do so? Photorespiration is increased when Version 1
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carbon dioxide is low or oxygen is high. By manipulating when stomata open and close, a plant can regulate the relative concentration of both gases, and in this way promote rubisco carboxylase activity. The molecule a plant uses to help regulate stomata opening and closing is ABA. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze how ABA might help regulate photorespiration during photosynthesis. • If you got the correct answer, good job! If you got an incorrect answer, did you remember how photorespiration works? Did you remember that rubisco is both a carboxylase and an oxygenase that is sensitive to levels of carbon dioxide and oxygen? Were you able to correlate ABA with the ability of the plant to open and close stomata and thereby regulate the relative amounts of oxygen and carbon dioxide? 62) A
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine which organic molecule would be the first to be labeled with 14C in a C4 plant. What type of thinking is required? • You are being asked to dissect, or analyze, which molecule in a C4 plant would be labeled with 14C first. Gather Content What do you already know about carbon fixation in C3, C4, and CAM plants? How does photosynthesis differ in these plants? What other information is related to the question? • Recall that plants are evolutionarily adapted to particular climates and environments. Part of a plant’s ability to adapt to an environment has to do with how and where it metabolizes carbon, and what happens to the machinery that fixes carbon when conditions are not optimal. It also has to do with the plant’s ability to balance intake of carbon dioxide with loss of water in hot, dry environments. C4 and CAM plants essentially use two strategies to address environmental stressors; separation of light reactions and carbon fixation by space and by time. Choose Answer Do you have all necessary information to determine which organic molecule would be first to be labeled with 14C in a C4 plant? • C4 and CAM plants use different strategies to deal with hot temperatures and water loss issues during the day. C4 plants acquire carbon dioxide and transport it in a different form to a separate location before making it available for the Calvin cycle. CAM plants acquire carbon dioxide at night when it is cooler and water loss is less likely to Version 1
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happen and store it until daytime when photosynthesis can take place. • Since we are talking about a C4 plant here, let’s focus on how that plant takes in carbon dioxide in its adverse environment. Recall that a C4 plant first locks carbon dioxide onto a three-carbon molecule to form a four-carbon oxaloacetate molecule. Thus, a carbon dioxide molecule labeled with 14C would first be incorporated into oxaloacetate before any of the other molecules. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze which molecule would be the first to be labeled with 14C in a C4 plant. • If you got the correct answer, well done! If you got an incorrect answer, were you able to identify which molecules receive carbon dioxide in C4 plants? Did you remember that oxaloacetate is a fourcarbon molecule? Were you able to recognize that 14C from the carbon dioxide must end up in oxaloacetate because it is the first molecule formed during carbon fixation in C4 plants? 63) B Both of these types of plants have adaptations that allow them to minimize photorespiration. As a result, they likely grow in hot, arid environments where stomata close to minimize water loss. 64) A Review Section 8.5. ATP is made as a result of chemiosmosis. 65) B
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine why ATP generated during cellular respiration is insufficient to drive the Calvin cycle in plants even when there is plenty of NADPH and CO2. What type of thinking is required? • You are being asked to break down possible scenarios, or analyze, why there isn’t enough ATP produced from cellular respiration to drive the Calvin cycle even when NADPH and carbon dioxide are not limited. Gather Content What do you already know about the Calvin cycle, photosynthesis, and cellular respiration in plants? What other information is related to the question? • Recall that photosynthesis is comprised of the light reactions and the Calvin cycle. ATP and NADPH, the main products of the light reactions, provide the energy and reducing power needed during the Calvin cycle to fix carbon dioxide from the atmosphere into an organic form. • Have you ever wondered how plants continue to operate during the night when the light reactions are not producing ATP and NADPH? Remember that plants also contain mitochondria in addition to chloroplasts; that means they are able to metabolize the sugars they produce during photosynthesis to produce ATP needed to operate a wide variety of cellular processes. • How efficient do you think it would be for a plant to operate the Calvin cycle using only ATP from cellular respiration? Choose Answer Do you have all the information need to determine why ATP from Version 1
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cellular respiration needs to be supplemented with ATP from the light reactions? • Let’s approach answering this question logically. Plants possess mitochondria, so the answer that says plants don’t undergo cellular respiration is clearly incorrect. And the fact that mitochondria exist in the same cell at the same time as chloroplasts indicates that answer is also not an option. • The Calvin cycle and the process of fixing carbon into an organic form from atmospheric carbon is an inherently energy-intensive process; it simply takes a great deal of energy to overcome entropy and create the more ordered organic molecules in the Calvin cycle. And while cellular respiration does produce ATP, it doesn’t produce enough to overcome the inherent energy inefficiency, nor does cellular respiration produce the NADPH needed during to fix carbon. • It’s not that cellular respiration can’t produce enough ATP, it’s that there wouldn’t be enough ATP production to cover the plant cell’s energy costs and still have enough left over to make excess carbohydrate. Thus, breaking down the sugar needed to provide the energy needed to make more sugar would be a zero sum proposition. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze why ATP produced during plant cellular respiration is insufficient to drive the Calvin cycle even when NADPH and carbon dioxide levels are sufficient. • If you got the correct answer, well done! If you got an incorrect answer, did you recall that plant cells contain mitochondria and Version 1
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chloroplasts? Were you able to determine why ATP from the light reactions and cellular respiration are needed to meet plant cell energy costs? Were you able to infer how inherently inefficient making sugar to break it down for energy to make sugar again would be? 66) C
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Clarify Question What is the key concept addressed by the question? • The question asks you to determine what would happen to photosynthesis if a particular plant mesophyll cell lacked an antenna complex What type of thinking is required? • You are being asked to dissect, or analyze, the photosynthetic outcome for a plant cell lacking an antenna complex. Gather Content What do you already know about the light reactions, photosystems, and antenna complexes? What other information is related to the question? • The first phase of photosynthesis includes the light reactions, where energy from the sun is captured using chlorophyll to remove electrons from water, excite them to a higher energy level, and then use redox reactions to produce ATP and NADPH. The ability to capture solar energy depends on photosystems, which are collections of many pigment molecules, some of which have specialized functions. • Antenna complexes contain hundreds of chlorophyll molecules and have the specialized ability to vastly increase the amount of energy that can be harvested by the plant. The antenna complex serves to harvest and direct its energy so that the electrons stripped from water can move to the reaction center complex of the photosystem. Considering the importance of the antenna complex, what do you suppose would happen in a mesophyll cell that lacked an antenna complex? How might this affect the light reactions and photosynthesis in that cell? Choose Answer Version 1
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Do you have the necessary information to dissect the problem? • Keep in mind for this question we are only talking about a single cell that lacks the antenna complex out of many that are perfectly fine. That said, let’s consider several options provided by the question. Considering how important an antenna complex is to the light reactions, it will certainly have some effect; the question is how much. • Is the cell that lacks the antenna complex incapable of harvesting light energy at all? Not so. The affected mesophyll cell is still capable of harvesting light, but poorly compared to cells with antenna complexes. Considering that there would be reduced energy capture due to a lack of antenna complexes, that means less energy to participate in electron transport, less proton pumping and a lower gradient, and ultimately less ATP and NADPH. • For the affected cell, less ATP and NADPH means less potential energy to drive the Calvin cycle, and less glucose will be produced as a result. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to analyze the photosynthetic outcome on a mesophyll plant cell lacking antenna complexes. • If you got a correct answer, well done! If you got an incorrect answer, did you recall that the light reactions rely on photosystems? Did you remember that photosystems contain antenna complexes and reaction centers? Were you able to infer that less ATP and NADPH in the affected mesophyll cell would mean less energy for the Calvin cycle to fix carbon and would produce less glucose as a result? Version 1
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Chapter 09 13e MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 1) The protein Sonic Hedgehog (SHH) plays a role in specifying the identity of digits (such as fingers and toes) in mammals. Several digits arise directly from cells that both express and respond to secreted SHH. What type of signaling would this be considered? A) Directcontact B) Paracrine C) Endocrine D) Synaptic E) Autocrine
2) One cell sends second messengers to another cell through gap junctions. What type of signaling would this be considered? A) Directcontact B) Paracrine C) Endocrine D) Synaptic E) Autocrine
3)
In synaptic signaling, neurotransmitters are released into a space that is referred to as a: A) chemicalsynapse. B) neuronjunction. C) paracrinespace. D) gap junction. E) plasmodesmata.
4) In response to injury, cell fragments called platelets become activated to induce clotting. Activated platelets release factors that can then bind to specific membrane receptors on nearby cells. What type of signaling would this be considered?
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A) Directcontact B) Paracrine C) Endocrine D) Synaptic E) Autocrine
5) A researcher is working to generate a new cancer drug. Thus far, he has identified a compound that can reduce the size of tumors in the lung. However, in order for the drug to work, the lung tumor has to be small. In addition, the tumor cannot have metastasized (spread to other areas of the body). Furthermore, he knows that the drug acts to prohibit the signaling from one tumor cell to another tumor cell. Given the above information, this new drug prohibits: A) synaptic signalingbetween tumor cells. B) autocrine signaling between tumor cells. C) paracrine signaling between tumor cells. D) endocrinesignaling between tumor cells.
6) Using a specific chemical, a cell biologist has blocked one type of channel-linked receptor in a lab rat's liver tissue. What was the likely mechanism of the chemical she used? A) The chemicalprohibits binding of a ligand to the receptor. B) The chemicalprohibits ions from entering the cell via active transport. C) The chemicalcauses ions to move in the opposite direction of the ion gradient. D) The chemicalprohibits second messenger signaling.
7) Leptin is a circulating hormone that is produced by fat cells and plays a role in body metabolism and obesity. It normally binds to receptors in the brain and inhibits appetite. Studies have demonstrated that when obese mice that are leptin deficient are injected with leptin they quickly lose their excess weight. Interestingly, many overweight people have high levels of leptin in their bloodstream. Why do you think the high levels of leptin in obese human individuals are insufficient to curb their appetite?
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A) Paracrine signaling may be disrupted in obese people with high levels of leptin. B) Obese people whohave high levels of leptin may have a leptin receptor with decreasedsensitivity. C) The form of leptin released by obese people may lack protein kinase activity. D) In obese people with high levels of leptin, it is a non-functional second messenger.
8) Vasopressin is a hormone that is primarily released when the body is low on water. Release of vasopressin causes the kidneys to conserve water by concentrating urine and decreasing urine output. However, vasopressin also has additional functions in other tissues such as the brain and blood vessels, which are not directly involved in urine production. How could it be possible for vasopressin to trigger different responses in different tissues? A) Vasopressin can bind to, and act on, different receptor subtypes, leading to different cellular responses in different tissues. B) Vasopressin can be released at different times to result in different effects. C) Vasopressin binds to the same exact receptor in different tissues, but causes a different conformational change to the receptor in each tissue. D) The kidneys have a receptor forvasopressin, but cells in the brain and blood vessels do not have a receptorfor vasopressin.
9) Addison's disease is a disorder that results from a reduction in production of glucocorticoids and mineralocorticoids. Individuals with Addison's disease suffer from a variety of systemic symptoms including: muscle weakness, fever, issues with the gastrointestinal tract, and increased tanning. Considering this information, what type of signaling do you think glucocorticoids and mineralocorticoids stimulate? A) Directcontact B) Paracrine C) Endocrine D) Synaptic E) Autocrine
10)
What is the function of a protein kinase?
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A) To removephosphate groups from proteins B) To cleavemembrane phospholipids C) To phosphorylate GDP to generate GTP D) To add phosphategroups onto proteins
11) You have identified a novel cytoplasmic protein. Through sequence analysis you are able to identify the presence of a number of serine/threonine phosphorylation motifs. Based on this data, you hypothesize that this protein may be a substrate for what kind of enzyme? A) A proteinkinase B) A receptortyrosine kinase C) A Gprotein-coupled receptor D) A tyrosinephosphatase E) A phospholipase
12) You have identified a molecule, molecule X, that can bind to the ATP binding site of a specific protein kinase, and prevent ATP binding. You are conducting a kinase assay using this protein kinase and a known substrate of this kinase, and have set up the reaction using the proper conditions and cofactors to allow for optimal protein kinase activity. If you add molecule X to the reaction, what do you predict will be the outcome? A) The substrate willbe phosphorylated normally in the presence of molecule X. B) Lessphosphorylation of the substrate will be seen in the presence of moleculeX. C) Morephosphorylation of the substrate will be seen in the presence of moleculeX.
13) Why are phosphorylation and dephosphorylation reactions commonly used to regulate signal transduction pathways?
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A) Phosphate groupsare efficient second messengers B) Protein kinasesand phosphatases are abundant in most cells C) The hydrolysis ofbound GTP generates GDP, which can change the activity of proteins bound toGDP D) The addition orremoval of a phosphate group can expose or hide potential binding sites inproteins or change protein activity
14) You are performing an experiment to assay phosphorylation of a substrate by a protein kinase. Based on the data in the table below, what do these experimental results suggest? Substrate
Protein kinase
GTP
Phosphorylation detected
Test sample
+
+
+
yes
Control #1
–
+
+
no
Control #2
+
–
+
yes
Control #3
+
+
–
no
A) GTP is not required for phosphorylation. B) The substrate can undergo autophosphorylation. C) The substrate is not required for phosphorylation. D) The protein kinase is required for phosphorylation.
15)
These molecules can directly convert extracellular signals into intracellular signals. A) Secondmessengers B) Scaffolds C) Membranereceptors D) Adapterproteins E) G proteins
16) When bound to a ligand, this type of receptor changes conformation to allow ions to move down their concentration gradient across the membrane:
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A) Channel-linkedreceptor B) Enzymaticreceptor C) G protein-coupledreceptor D) Steroid hormonereceptor
17) Growth of new blood vessels is stimulated by vascular endothelial growth factor (VEGF). This ligand binds to the VEGF receptor, which leads to the dimerization and autophosphorylation of this receptor on cytoplasmic tyrosines. What type of receptor is the VEGF receptor? A) Channel-linkedreceptor B) Enzymaticreceptor C) G protein-coupledreceptor D) Steroid hormonereceptor
18) What type of receptor is not an enzyme, but is directly associated with an enzyme that can hydrolyze GTP? A) Channel-linkedreceptor B) Enzymaticreceptor C) G protein-coupledreceptor D) Steroid hormonereceptor
19) You are planning to perform some protein-protein interaction studies to identify a receptor for a steroid hormone you have been working on. You start by fractionating the cell. What cell fraction would you want to work with to identify the steroid hormone receptor of interest? A) The plasmamembrane fraction B) The extracellularfraction C) The cytoplasmicfraction D) The mitochondrialfraction E) The ribosomal fraction
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20)
What property defines most ligands for intracellular receptors?
A) They arelipid-soluble B) They arehydrophilic C) They aremolecules that can perform significant hydrogen bonding interactions withwater D) They are largemolecules
21) You are interested in developing an inhibitor for the estrogen receptor. You have identified a molecule that is small and hydrophilic. In a test tube, this inhibitor binds tightly to the estrogen receptor, and inhibits the interaction of the receptor with estrogen. Do you think that this molecule will be an effective inhibitor of the estrogen receptor in cells? A) Yes, because itcan prevent estrogen binding. B) Yes, because itis small. C) No, because it ishydrophilic. D) No, because itwill need to bind to the DNA-binding domain to act as an inhibitor.
22) Tamoxifen is a drug that is used to treat breast cancer. It inhibits the activities of the estrogen receptor in breast epithelial cells, which are the cells that are relevant to breast cancer. One of the concerns that scientists had during the development of Tamoxifen as a therapy for breast cancer was that other cell types require estrogen signaling for their function. For example, it is known that cells in bone tissue require estrogen signaling. As a result, there was a concern that use of Tamoxifen would lead to bone loss in patients. In reality, however, researchers were surprised to find that Tamoxifen actually led to an increase in bone density in breast cancer patients. At the same time, Tamoxifen did inhibit the activity of the estrogen receptor in breast epithelial cells in these patients. What is the best explanation for this finding? A) Tamoxifen bindsdifferent parts of the estrogen receptor in different tissues. B) The estrogenreceptor is bound to different coactivators in different tissues. C) Tamoxifen canonly enter certain cell types. D) Bone cells makeuse of a different type of estrogen receptor that does not bind toTamoxifen.
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23) A mutation in the DNA-binding domain of a steroid hormone receptor is most likely to affect what aspect of receptor function? A) Theconformational change of the receptor B) The binding ofthe hormone to the receptor C) The translocationof the receptor to the nucleus D) The cellularresponse to the hormone
24) You are having lunch with an elderly friend when suddenly he begins to experience chest pain and tightness. He reaches into his pocket, gets out one of his nitroglycerin tablets and quickly takes it. After the episode passes, your friend asks you how the nitroglycerin helps his angina. You explain that nitroglycerin gets converted by cells to nitric oxide (NO) causing the smooth muscle cells of the blood vessel to relax and increase blood flow to the heart. He pushes you for a more detailed explanation, so you explain further that: A) NO activates guanylyl cyclase, which catalyzes the synthesis of cGMP, which acts as an intracellular messenger in a pathway leading to smooth muscle relaxation. B) NO activates a protein kinase which catalyzes the synthesis of cGMP, which acts as an intracellular messenger in a pathway leading to smooth muscle relaxation. C) NO inhibits guanylyl cyclase, which allows the build up of cGMP, which acts as an intracellular messenger in a pathway leading to smooth muscle relaxation. D) NO activates cGMP, which catalyzes the synthesis of guanylyl cyclase, which acts as an intracellular messenger in a pathway leading to smooth muscle relaxation.
25) What is the mechanism by which binding of testosterone to the testosterone receptor leads to upregulated gene transcription?
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A) Binding oftestosterone to the testosterone receptor leads to the increase in secondmessengers that activate a kinase cascade, ultimately leading to the activationof transcription factors that promote gene transcription. B) Binding oftestosterone to the testosterone receptor leads to the activation of a Gprotein that stimulates the activation of enzymes that promote genetranscription. C) Binding oftestosterone to the testosterone receptor leads to a conformational change thatallows the receptor to enter the nucleus where it can bind to DNA and promotegene transcription. D) Binding of testosterone to the testosterone receptor leads to the opening of an ion channel that leads to an increase in calcium in the cytoplasm. The increased calcium levels activate calmodulin, which can go on to activate other proteins that promote gene transcription.
26)
How are receptor tyrosine kinases and steroid hormone receptors similar? A) Both areactivated by autophosphorylation B) Both aretransmembrane proteins with a single transmembrane domain C) Both have aDNA-binding domain D) Both have a sitefor binding ligand
27) Some cancers are caused by the overexpression of receptor tyrosine kinases (RTKs). It is known that RTK signaling pathways commonly stimulate cell division. Why would the overexpression of receptor tyrosine kinases lead to cancer development?
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A) RTKs are activated by dimerization, caused by ligand binding. If there are too many receptors on the cell surface, it is possible that these receptors dimerize in the absence of ligand binding, thus stimulating cell division at inappropriate times. B) If there are too many RTKs on the cell surface, this will tend to allow cells to adhere to each other. Once they adhere, RTKs from one cell can bind to RTKs from another cell, and they can activate each other leading to activation of downstream signaling pathways in both cells. C) If there are too many RTKs on the cell surface, it is less likely that inhibitors will bind to all of the available RTKs and block their ability to enter the nucleus. As a result, some of the RTKs will be able to enter the nucleus to stimulate transcription. D) If there are too many RTKs on the cell surface, this will promote the inhibition of autophosphorylation. In the absence of autophosphorylation, it is more likely that the RTK downstream signaling pathway will be active.
28)
What signaling pathway commonly makes use of a G protein to transduce the signal? A) Channel-linkedreceptor pathways B) Steroid hormonereceptor pathways C) Receptor tyrosinekinase pathways
29) Your research project involves the characterization of a particular signal transduction pathway. Specifically, you have been studying a receptor tyrosine kinase and protein X, which initiates downstream events. You are certain that protein X is part of the signal transduction pathway, but have been unable to identify a direct protein-protein interaction between the receptor tyrosine kinase and the protein X. What should you do next in your attempt to identify a link between the receptor tyrosine kinase and protein X? A) Try to identify a coactivator protein. B) Try to identify proteins that act downstream of protein X. C) Try to identify an adapter protein that can interact with both the receptor and protein X. D) Confirm theinteraction between the receptor tyrosine kinase and its ligand.
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30) The protein SOS is a guanine nucleotide exchange factor for Ras. SOS helps facilitate the exchange of GDP for GTP. What would be the effect of a mutation that inhibits the interaction between SOS and Ras? A) GTP would remainbound to Ras, thereby keeping Ras constitutively active. B) GDP would remainbound to Ras, thereby preventing Ras activation. C) Ras would be morelikely to hydrolyze GTP to GDP. D) There would be noeffect.
31) Many receptor tyrosine kinase (RTK) pathways lead to the activation of Ras. To activate Ras, it is necessary to recruit a guanine nucleotide exchange factor to the plasma membrane, because Ras is a membrane associated protein. Guanine nucleotide exchange factors, such as SOS, stimulate the exchange of GDP for GTP. However, SOS cannot bind directly to most RTKs. The protein Grb2 has a domain that can bind to phosphorylated tyrosines, and another domain that can bind to SOS. Therefore, Grb2 can bind to active RTKs and recruit SOS to the plasma membrane. Grb2 is an example of what kind of signaling molecule? A) Scaffold B) Adapterprotein C) Secondmessenger D) Enzyme
32) Ste5 binds to MAPKKK, MAPKK, and MAPK to organize the kinase cascade. What type of signaling molecule is Ste5? A) Scaffold B) Adapterprotein C) Secondmessenger D) Enzyme
33) Many receptor tyrosine kinase pathways have MAPK as a downstream signaling component. MAPK can phosphorylate target proteins. What type of signaling molecule is MAPK?
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A) Scaffold B) Adapterprotein C) Secondmessenger D) Enzyme
34) A small number of cell surface receptors can ultimately generate a large intracellular response due to activation of kinase cascades. This is referred to as: A) signalamplification. B) signaltransduction. C) signaldampening. D) signalactivation.
35)
What enzyme phosphorylates MAP kinase kinase? A) MAP kinase B) MAP kinase kinase C) MAP kinase kinase kinase D) MAP phosphatase
36) The cell surface receptors that can act only indirectly on plasma membrane-bound enzymes or ion channels are called: A) G protein-coupledreceptors. B) gated ion channels. C) enzymatic receptors. D) second messenger receptors.
37) G protein-coupled receptors are the largest family of cell surface receptors. Each receptor passes through the plasma membrane how many times?
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A) Once B) Three times C) Five times D) Seven times
38) In the nitric oxide signaling pathway, nitric oxide activates an enzyme that can convert many molecules of GTP into molecules of cGMP. cGMP is a small molecule that can diffuse through the cytoplasm and bind to an enzyme called protein kinase G (PKG). Binding of cGMP to PKG leads to a change in the confirmation of PKG that leads to its activation. What type of signaling molecule is cGMP? A) Scaffold B) Adapterprotein C) Secondmessenger D) Enzyme
39) Some enzymatic receptors and most G protein-coupled receptors transmit the signal into the cytoplasm by utilizing other substances within the cytoplasm that are referred to as: A) genes. B) intracellular receptors. C) second messengers. D) first messengers.
40) A mutation that affects Ca++ binding to calmodulin is most likely to interfere with what aspect of a signal transduction pathway? A) The flow ofCa++ ions through ion channel receptors B) The cellularresponse to the second messenger C) The MAP kinasecascade D) G protein activity
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41) If the effector protein phospholipase C failed to cleave phosphatidylinositol-4,5bisphosphate (PIP2), the action of what enzyme would be affected? A) cAMP B) IP3 C) protein kinase A (PKA) D) protein kinase C (PKC)
42) What is similar about G protein-coupled receptors (GPCRs) and receptor tyrosine kinases (RTKs)? A) Both are directlybound to G proteins B) Both can activate phospholipase C C) Both areenzymes D) Both areactivated by autophosphorylation
43)
The function of adenylyl cyclase is to: A) catalyze theconversion of ATP to cAMP. B) cleavePIP2 into DAG and IP3. C) directly activateprotein kinase A (PKA). D) stimulate therelease of calcium from the endoplasmic reticulum.
44) What is the difference between Ras and the G proteins bound to G protein coupled receptors (GPCRs)? A) Ras is an enzymeand the G proteins bound to GPCRs are not enzymes. B) Ras is a secondmessenger and the G proteins bound to GPCRs are not second messengers. C) Ras is a small Gprotein and the G proteins bound to GPCRs are not small G proteins. D) Ras can activatedifferent effector molecules and the G proteins bound to GPCRs cannot activatedifferent effector molecules.
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45)
What second messenger is directly involved in activating protein kinase C (PKC)? A) DAG B) cAMP C) cGMP D) PhospholipaseC E) G protein
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Answer Key Test name: Chap 09_13e_Raven 1) E If a cell responds to the ligand that it secretes, this is considered autocrine signaling. 2) A Gap junctions require direct contact between cells, and thus this is an example of direct contact signaling. 3) A 4) B Since the factors are acting on cells in the local environment, this is an example of paracrine signaling. 5) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about signaling involved in cancer growth. • What type of thinking is required? o You are being asked to analyze the signaling involved in cancer growth. Gather Content • What do you know about signaling involved in cancer growth? What other information is related to the question? o Synaptic signaling occurs between neurons across a synapse. Autocrine signaling is a cell talking to itself. Endocrine signaling involves hormones that travel through the blood to act on different organs. Paracrine signaling involves communication with nearby cells. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Since the drug only works on small tumors that have not metastasized, and prevents signaling from one cell to another cell, it must inhibit paracrine signaling. Synaptic signaling is irrelevant in this case, as signaling does not involve neurons. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze the signaling involved in cancer Version 1
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growth. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that synaptic signaling would stimulate growth in a cell? Did you think that endocrine signaling worked on nearby cells? 6) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about specifically inhibiting one class of receptors. • What type of thinking is required? o You are being asked to apply your knowledge about specifically inhibiting one class of receptor. Gather Content • What do you know about specifically inhibiting one class of receptors? What other information is related to the question? o Receptors bind to specific ligands. This binding can activate the opening of ion channels or produce second messengers. Multiple receptors can activate similar pathways, but only one ligand binds each receptor. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o To specifically inhibit one receptor a chemical that binds to the ligand binding site would work best. Chemicals that block the movement of ions do not specifically block the action of one receptor. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about specifically inhibiting one class of receptors. If you got the correct answer, great job! Version 1
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If you got an incorrect answer, where did the process break down? Did you think that blocking movement of ions would be specific to one receptor? Did you think that ion transport would use second messenger signaling? 7) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about resistance to leptin. • What type of thinking is required? o You are being asked to analyze why some obese people are resistance to leptin. Gather Content • What do you know about resistance to leptin? What other information is related to the question? o For a hormone like leptin to function it must bind to a receptor. This then allows a signal to pass into the cell. If the hormone levels are low, or the receptor does not work properly then the cells do not respond to the hormone. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o If a person lacks leptin or the receptor, their brain will not receive the signal that they are full so their appetite will not be inhibited. Obese individuals who have normal leptin levels but low leptin receptor activity will not respond to the leptin, will be hungry more often and are likely to become obese. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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o This question asked you to analyze why some obese people are resistance to leptin. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that leptin was a paracrine signal instead of endocrine? Did you think that leptin was a second messenger or kinase? 8) A 9) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about different types of signaling. • What type of thinking is required? o You are being asked to analyze what type of signaling glucocorticoids and mineralocorticoids perform. Gather Content • What do you know about different types of signaling? What other information is related to the question? o Signaling with adjacent cells include paracrine, direct contact, synaptic and autocrine. Endocrine signaling works at a distance with the hormones moving through the blood to distant organs. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Since the symptoms of this disease are systemic and occur throughout the body, this is an example of endocrine signaling. In fact, glucocorticoids and mineralocorticoids are hormones, and this disease is considered an endocrine disorder. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze what type of signaling glucocorticoids and mineralocorticoids perform. If you got the correct Version 1
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answer, great job! If you got an incorrect answer, where did the process break down? Did you think that by affecting many organs glucocorticoids and mineralocorticoids only worked on nearby cells? Did you think that glucocorticoids and mineralocorticoids were not hormones? 10) D Protein kinases phosphorylate proteins. 11) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about phosphorylation of a protein. • What type of thinking is required? o You are being asked to apply your knowledge about phosphorylation of a protein. Gather Content • What do you know about phosphorylation of a protein? What other information is related to the question? o The class of enzyme that adds phosphate groups from ATP to proteins is called a protein kinase. These phosphate groups can be added to the three amino acids that have an OH as part of their R group; such as serine, threonine, and tyrosine. We categorize protein kinases as either serine–threonine or tyrosine kinases based on the amino acids they modify. Most cytoplasmic protein kinases fall into the serine–threonine kinase class. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Since this protein has serine and threonine phosphorylation motifs, it may be a substrate for serine-threonine phosphatases and kinases. Phospholipases cleave phospholipids. GPCRs are not enzymes. Phosphatases remove phosphates from proteins. Reflect on Process • Did your problem-solving process lead you to the correct answer? Version 1
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If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about phosphorylation of a protein. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that the serine-threonine phosphorylation sites were a substrate for a tyrosine kinase? Did you think that a phosphatase adds a phosphate to a protein? 12) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the effects of a kinase inhibitor. • What type of thinking is required? o You are being asked to analyze statements about the effects of a kinase inhibitor. Gather Content • What do you know about kinase inhibitors? What other information is related to the question? o The class of enzyme that adds phosphate groups from ATP to proteins is called a protein kinase. These phosphate groups can be added to the three amino acids that have an OH as part of their R group: serine, threonine, and tyrosine. We categorize protein kinases as either serine– threonine or tyrosine kinases based on the amino acids they modify. Most cytoplasmic protein kinases fall into the serine–threonine kinase class. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o If this molecule prevents ATP binding to the kinase, this will inhibit the reaction catalyzed by the kinase. This is because the kinase acts to transfer the terminal phosphate of ATP onto its substrate. If binding to ATP is inhibited, then the kinase will not have a source of phosphate nor the energy source needed to drive this endergonic reaction. In fact, this is an approach that is used by multiple drugs that are known kinase inhibitors.
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze statements about the effects of a kinase inhibitor. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that the substrate could be phosphorylated without the activity of the kinase? Did you think that the inhibitor would increase kinase activity? 13) D 14) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the results of a phosphorylation assay. • What type of thinking is required? o You are being asked to analyze the results of a phosphorylation assay. Gather Content • What do you know about phosphorylation? What other information is related to the question? o The class of enzyme that adds phosphate groups from GTP to substrates is called a kinase. These phosphate groups can be added to the substrate by the enzyme. In the assay, a “+” indicates that that component was added to the reaction and a “–“ indicates that it was left out. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o In the experiment the substrate was phosphorylated in the two conditions where the substrate and GTP were present. The substrate could still be phosphorylated when the kinase was absent, indicating that the kinase was not necessary for phosphorylation. The best answer is that the substrate could phosphorylate itself even in the absence of the kinase. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze the results of a phosphorylation assay. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that the kinase was necessary for phosphorylation of the substrate? Did you think that GTP was not necessary for phosphorylation of the substrate?
15) C 16) A 17) B 18) C 19) C
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Steroid hormone receptors are intracellular receptors, and of these choices, would most likely be found in the cytoplasm. 20) A They are mostly lipophilic molecules so that they can penetrate the lipid bilayer and interact with their receptors. 21) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about an inhibitor of the estrogen receptor. • What type of thinking is required? o You are being asked to analyze statements about an inhibitor of the estrogen receptor. Gather Content • What do you know about an inhibitor of the estrogen receptor? What other information is related to the question? o The nonpolar structure of steroid hormones like estrogen allow these hormones to cross the membrane and bind to intracellular receptors. The location of steroid hormone receptors prior to hormone binding is cytoplasmic, but their primary site of action is in the nucleus. Binding of the hormone to the receptor causes the complex to shift from the cytoplasm to the nucleus. As the ligand–receptor complex moves to the nucleus of the cell, these receptors are often called nuclear receptors. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Because this molecule is hydrophilic, it will have a difficult time passing through the plasma membrane. Because the estrogen receptor is an intracellular receptor, this will not likely be an effective inhibitor. If the molecule were hydrophobic then it would be a good inhibitor. Reflect on Process • Did your problem-solving process lead you to the correct answer? Version 1
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If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze statements about an inhibitor of the estrogen receptor. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that the inhibitor could diffuse across the membrane even though it is hydrophilic? Did you think that the estrogen receptor was on the surface of the cell? 22) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the effects of tamoxifen on different cells after binding to the estrogen receptor. • What type of thinking is required? o You are being asked to evaluate explanations for the effects of tamoxifen on different cells after binding to the estrogen receptor. Gather Content • What do you know about the effects of tamoxifen on different cells after binding to the estrogen receptor? What other information is related to the question? o The nonpolar structure of steroid hormones like estrogen allows these hormones to cross the membrane and bind to intracellular receptors. The location of steroid hormone receptors prior to hormone binding is cytoplasmic, but their primary site of action is in the nucleus. Binding of the hormone to the receptor causes the complex to shift from the cytoplasm to the nucleus. The ligand–receptor complex goes to the nucleus of the cell, where it will bind to different cofactors in the nucleus. Depending on which cofactors the estrogen receptor binds to, different genes will be turned on in different cell types. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Tamoxifen binding in breast epithelial cells results in the recruitment of different coactivators than are recruited when tamoxifen binds to the estrogen receptor in bone tissue. Tamoxifen can clearly enter bone cells and bind to the estrogen receptors there, as there is an increase in bone Version 1
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density in patients being treated with Tamoxifen. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to evaluate explanations for the effects of tamoxifen on different cells after binding to the estrogen receptor. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that tamoxifen could not enter bone cells? Did you think that bone cells made a different estrogen receptor? 23) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about steroid receptors. • What type of thinking is required? o You are being asked to analyze statements about steroid receptors. Gather Content • What do you know about steroid receptors? What other information is related to the question? o The nonpolar structure of steroid hormones allows these hormones to cross the membrane and bind to intracellular receptors. The location of steroid hormone receptors prior to hormone binding is cytoplasmic, but their primary site of action is in the nucleus. Binding of the hormone to the receptor causes the complex to shift from the cytoplasm to the nucleus. In the nucleus, the steroid receptor binds to DNA and turns on different genes based on the different cell types. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o A mutation in the DNA-binding domain of a steroid receptor would prevent it from binding to the promoters of some genes. If these genes were not expressed normally it would affect the cellular response to the hormone. A mutation in the DNA binding domain would not affect the binding of the hormone to the receptor, its conformational change after binding, or moving into the nucleus. Reflect on Process
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze statements about steroid receptors. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that mutations in the DNA binding domain of a steroid receptor would affect its ability to bind to the hormone? Did you think that mutations in the DNA binding domain of a steroid receptor would affect its movement to the nucleus? 24) A 25) C 26) D 27) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about over expression of receptor tyrosine kinases. • What type of thinking is required? o You are being asked to analyze statements about over expression of receptor tyrosine kinases. Gather Content • What do you know about receptor tyrosine kinases? What other information is related to the question? o Receptor tyrosine kinases have a relatively simple structure consisting of a single transmembrane domain, an extracellular ligand-binding domain, and an intracellular kinase domain. This kinase domain contains the catalytic site of the receptor, which acts as a protein kinase that adds phosphate groups to tyrosines. When a ligand binds to this specific receptor in two seperate instances, these two receptor–ligand pairs can dimerize and phosphorylate each other. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Dimerization leads to the activation of RTKs, and if there are too many receptors on the cell surface, it is more likely that dimerization and activation of the signaling pathway will happen in the absence of ligand. This can lead to the inappropriate activation of a signaling pathway that promotes cell division. Dimerization and autophosphorylation has to occur with RTKs in the same cell. There is no mechanism for this occurring between two different cells. RTKs are membrane bound proteins that do not enter the nucleus. Autophosphorylation is necessary Version 1
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for activation of this pathway and thus if autophosphorylation were inhibited, it would be less likely that the downstream pathway would be active. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze statements about the overexpression of receptor tyrosine kinases. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that receptor tyrosine kinases allow cells to bind to each other? Did you think that receptor tyrosine kinases enter the nucleus of a cell once they are activated? 28) C Receptor tyrosine kinase pathways commonly use the protein Ras to transduce the signal. Ras is a small G protein. 29) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about the signaling pathway activated by a receptor tyrosine kinase. • What type of thinking is required? o You are being asked to evaluate an experiment on the signaling pathway activated by a receptor tyrosine kinase. Gather Content • What do you know about the signaling pathway activated by a receptor tyrosine kinase? What other information is related to the question? o When a receptor tyrosine kinase is activated it dimerizes and autophosphorylates itself. This then passes a signal to adapter proteins that carry the signal to other proteins in the cell. At the end of the signaling pathway a transcription factor is typically activated increasing gene expression. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o If the receptor and protein X do not seem to be interacting directly then it is possible that another adapter protein is necessary to carry the signal from the receptor to protein X. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? o This question asked you to evaluate an experiment on the signaling pathway activated by a receptor tyrosine kinase. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that proteins downstream of protein X would affect the interaction between the receptor and protein X? Did you think that the interaction between the ligand and receptor would interfere with binding between the receptor and protein X? 30) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the interaction between Ras and SOS. • What type of thinking is required? o You are being asked to analyze what would happen if Ras and SOS could not interact. Gather Content • What do you know about the interaction between Ras and SOS? What other information is related to the question? o The protein SOS is a guanine nucleotide exchange factor for Ras. SOS helps facilitate the exchange of GDP for GTP.Ras is a G-protein that is active when GTP is bound to it. Ras can then cleave a phosphate off of GTP forming GDP to go into the inactive state. When SOS replaces GDP with GTP it reactivates the Ras. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Without SOS, Ras would have GDP bound to it and could not replace the GDP with GTP. Without GTP, the Ras would be inactive. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze what would happen if Ras and SOS could not interact. If you got the correct answer, great job! If you Version 1
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got an incorrect answer, where did the process break down? Did you think that GTP would remain bound to Ras in the absence of SOS? Did you think that Ras would increase breakdown of GTP into GDP? 31) B 32) A 33) D 34) A 35) C 36) A 37) D 38) C 39) C 40) B 41) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about enzymes activated by inositol triphosphate. • What type of thinking is required? o You are being asked to apply your knowledge about enzymes activated by inositol triphosphate. Gather Content • What do you know about enzymes activated by inositol triphosphate? What other information is related to the question? o A common second messenger is produced from the molecule called inositol phospholipid. These molecules are inserted into the plasma membrane by their lipid ends and have the inositol phosphate portion protruding into the cytoplasm. The most common inositol phospholipid is phosphatidylinositol-4,5-bisphosphate (PIP2). This molecule is a substrate of the effector protein phospholipase C, which cleaves PIP2 to yield diacylglycerol (DAG) and inositol-1,4,5-trisphosphate (IP3).Both of these compounds then act as second messengers with a variety of cellular effects. DAG, like cAMP, can activate a protein kinase; in this case protein kinase C (PKC). Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o When inositol triphosphate (IP3) is produced by phospholipase C it actives protein kinase C. Protein kinase A is activated by cAMP. cAMP and IP3 are second messengers and not enzymes. Reflect on Process Version 1
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about enzymes activated by inositol triphosphate. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that cAMP or IP3 were enzymes? Did you think that protein kinase A was activated by IP3? 42) B 43) A 44) C 45) A
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Chapter 10 13e MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 1) In bacterial cell division, the cell divides into two nearly equal halves. This process is referred to as: A) binaryfission B) mitosis C) fusion D) meiosis E) cytokinesis
2) How does the organization of the bacterial genome differ from the organization of the eukaryotic genome? A) The compaction ofthe eukaryotic genome involves structural maintenance of chromosome (SMC)proteins, and the compaction of the bacterial genome does not. B) Most bacterial chromosomes are circular and the eukaryotic chromosomes contained in the nucleus are not. C) Bacterialchromosomes are made up of RNA and eukaryotic chromosomes are made up ofDNA. D) The eukaryotic genome is found in chromosomes and there are no chromosomes in bacterial cells. E) Eukaryotic chromosomes have to be tightly packed to fit into the nucleus,and bacterial chromosomes do not require tight packing to fit into thecell.
3)
The division of a bacterial cell occurs as the: A) cell wall develops cracks around the equator of the cell. B) chromosomes are pulled toward the ends of the cell. C) actin andmicrotubules constrict the cytoplasm. D) new membrane andcell wall materials begin to grow and form a septum.
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4) If a cell contained a mutation in the gene that encodes FtsZ, which process would be affected? A) Septation B) Cytokinesis C) Prophase D) DNA Synthesis E) Cohesin cleavage
5) Fitting the very long DNA strands from a chromosome into the limited space of the nucleus is achieved by coiling the DNA around beads of histones with repeating subunits. These DNA-wrapped histones are called: A) Solenoids B) Nucleosomes C) Chromatinloops D) Rosettes
6) The point of constriction on chromosomes that contains certain repeated DNA sequences that bind specific proteins is called: A) Thekinetochore B) Thecentromere C) The cohesincomplex D) The centriole E) The centrosome
7) Eukaryotic chromosome complexes are composed of 60% protein and 40% DNA. This complex is referred to as:
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A) The histonecomplex B) Chromatin C) Thekinetochore D) Cohesin
8)
The number of chromosomes in diploid eukaryotic cells: A) is 46. B) can be predictedby the size of the organism. C) changes as eachorganism grows and ages. D) variesconsiderably from 2 to over 1000 in different species.
9) A person whose cells all contain chromosomes with a number '2n+1' are most likely to have what type of condition? A) Monosomy B) Trisomy C) Cancer D) Obesity E) None, this is thenormal chromosome number for humans.
10) In later chapters, you will learn more about the regulation of gene expression. One way a cell can regulate gene expression is to alter how tightly the DNA is condensed into TADs and compartments. The more tightly condensed a particular region of DNA is, the less likely genes in that region will be expressed. Bearing this in mind, how condensed do you think regions of heterochromatin are? A) Very tightly B) Moderately C) Loosely D) Not at all
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11)
A scientist wants to study histones. Histones are:
A) proteins thatdouble-stranded DNA molecules wrap around in eukaryotes. B) proteins thatdouble-stranded DNA molecules wrap around in prokaryotes and eukaryotes. C) proteins thatregulate checkpoints in the mitotic cell cycle. D) proteins thatserve as the spindle fiber to pull sister chromatids apart during anaphase. E) proteins thatrequired for the activity of Cdk enzymes.
12) The two copies of each type of chromosome found in normal somatic (body) cells in an organism, throughout the cell cycle, are called: A) Sisterchromatids B) Homologouschromosomes C) Daughterchromosomes D) Kinetochores
13) Before cell division of somatic cells, each chromosome must be replicated. After replication, the resulting two parts of each chromosome are held together by cohesin at the centromere. These two parts are referred to as: A) Sisterchromatids B) Homologouschromosomes C) Daughterchromosomes D) Kinetochores E) Genes
14)
These structures are held together by cohesin:
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A) Nucleosomes B) Sisterchromatids C) Homologouschromosomes D) Solenoids
15) A cell biologist produces a karyotype of mouse somatic cells arrested in mitosis. She sees 40 chromosomes, which is completely normal for mice. Based on this information, what is the haploid number of chromosomes for mice? A) 10 B) 20 C) 40 D) 80 E) It cannot be determined from the information provided.
16) If there are 32 sister chromatids in a normal somatic cell, what is the haploid number for that cell? A) 8 B) 16 C) 32 D) 64
17) If there are 32 sister chromatids in a normal somatic cell, how many chromosomes are there? A) 8 B) 16 C) 32 D) 64
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18) A somatic cell from a garden pea plant normally contains 14 chromosomes. How many sister chromatids would that cell contain during G1 of the cell cycle? A) 0 B) 7 C) 14 D) 28
19) A somatic cell from a corn plant normally contains 20 chromosomes. How many sister chromatids would that cell contain during G2 of the cell cycle? A) 0 B) 10 C) 20 D) 40
20)
What is the sequence of events in a typical eukaryotic cell cycle? A) G1 to G2 to S tomitosis to cytokinesis B) G1 to S to G2 tomitosis to cytokinesis C) G1 to S to G2 tocytokinesis to mitosis D) G1 to G2 tomitosis to S to cytokinesis E) S to G1 to G2 tomitosis to cytokinesis
21) The portion of the cell cycle when the cell is growing and does not contain a replicated genome is referred to as: A) G1 B) S C) G2 D) Mitosis E) Cytokinesis
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22)
The stage of the cell cycle during which the cytoplasm divides to form two cells is called: A) G1 B) S C) G2 D) Mitosis E) Cytokinesis
23) This stage of the cell cycle is characterized by growth and it contains a checkpoint to verify that all of the DNA has been replicated prior to mitosis. A) G1 B) S C) G2 D) Mitosis E) Cytokinesis
24) A duplicate copy of all of the hereditary information contained in the nucleus of eukaryotic cells is made during what stage of the cell cycle? A) G1 B) S C) G2 D) Mitosis E) Cytokinesis
25) The physical distribution of cytoplasmic material into the two daughter cells in plant cells is referred to as:
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A) The gap phase B) Cytokinesis C) Binaryfission D) Interphase
26) If a cell has 32 chromosomes prior to S and undergoes mitosis followed by cytokinesis, each new daughter cell will have how many chromosomes? A) 64 B) 32 C) 16 D) 8
27) Embryonic cell cycles allow the rapid division of cells in the early embryo. These cell cycles are much shorter in length than the cell cycles of cells in a mature organism. In embryonic cell cycles, mitosis takes approximately the same amount of time as it does in the cell cycles of mature cells. Considering that the timing of the embryonic cell cycle is shorter but the portion of the cell cycle that involves mitosis is the same as in a mature cell, which of the following would be a result of the embryonic cycle? A) Resulting daughter cells are smaller than the parent cell in the embryonic cell cycles. B) Resulting daughter cells do not contain the same genetic information as the parent cell in the embryonic cell cycles. C) Resulting daughter cells cannot form a mitotic spindle in the embryonic cell cycle. D) The parent cell of the embryonic cell cycle spends the majority of its time in G0.
28) In what portion of the cell cycle do the chromosomes appear invisible under a light microscope because they are not yet condensed?
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A) Interphase B) Prophase C) Metaphase D) Anaphase E) Telophase
29)
Interphase is made up of what stages of the cell cycle? A) G1 + G2 + S B) S +cytokinesis C) prophase + metaphase + anaphase + telophase D) cytokinesis + mitosis E) G0 + G1 + G2
30)
During what stages of the cell cycle are sister chromatids bound together by cohesin? A) G1, S,G2 B) S,G2 C) G1,S D) S, G2,prophase, metaphase E) S, G2, prophase, metaphase,anaphase, telophase
31) Following S phase, a human cell would have how many pairs of sister chromatids and individual DNA molecules? A) 23 pairs of sister chromatids and 46 individual DNA molecules B) 23 pairs of sister chromatids and 92 individual DNA molecules C) 46 pairs of sister chromatids and 46 individual DNA molecules D) 46 pairs of sister chromatids and 92 individual DNA molecules E) 46 pairs of sister chromatids and 184 individual DNA molecules
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32) If a chromosome contains a mutation such that it cannot bind to the kinetochore complex, what would be the consequence? A) That chromosomewould not be able to be replicated. B) That chromosomewould not be able to condense. C) That chromosomewould not be able to bind to the mitotic spindle. D) That chromosomewould not be able to interact with histone proteins.
33) Consider the cell cycle of a human cell. During G2, what is the state of the homologous chromosomes? A) The homologouschromosomes are lined up on the equator of the cell. B) The homologouschromosomes have all been copied through DNA replication and are beginning tocondense. C) The homologous chromosomes have been pulled to their respective poles by the spindle apparatus. D) The homologous chromosomes have not been replicated yet. E) The homologous chromosomes are now in the haploid or n condition.
34) This is the stage of mitosis characterized by the alignment of the chromosomes in a ring along the inner circumference of the cell: A) Interphase B) Telophase C) Prophase D) Metaphase
35) The stage of mitosis characterized by the physical separation of sister chromatids is called:
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A) Anaphase B) Metaphase C) Prometaphase D) Telophase
36) This stage of mitosis is characterized by the disassembly of spindle apparatus, the reestablishment of the nuclear membrane, and the decondensation of the chromosomes: A) Prometaphase B) Telophase C) Anaphase D) Metaphase
37) During this stage of mitosis, the nuclear envelope begins to break down and the spindle begins to form. A) Anaphase B) Metaphase C) Prophase D) Telophase E) Prometaphase
38) During this stage of mitosis, the chromosomes become attached to the spindle at their kinetochores. A) Prophase B) Prometaphase C) Metaphase D) Anaphase E) Telophase
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39)
What happens during Anaphase B? A) Kinetochores arepulled toward the poles. B) The spindle polesmove apart. C) The spindleapparatus disassembles. D) The nuclearenvelope reforms. E) The APC/C getsactivated for the first time.
40) You are conducting a genetic screen using Caenorhabditis elegans embryos to isolate mutations affecting anaphase (A). Therefore, you need to look for embryos in which A) the centromeres do not move toward the poles. B) the poles do not move apart. C) the spindle apparatus does not disassemble. D) sister chromatidsare mismatched and therefore fail to separate.
41)
What stage of mitosis is essentially the reverse of prophase? A) Anaphase B) Prometaphase C) Metaphase D) Telophase E) Cytokinesis
42) The drug Taxol, or Paclitaxel, is used to treat patients with a variety of cancers, including breast, lung and ovarian cancers. The drug works by stabilizing microtubules, and preventing their disassembly. The goal of this drug is to prevent dividing cells from completing mitosis. As a result, cancerous cells can no longer divide. In a cell treated with Taxol, at what stage of mitosis will the cells arrest?
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A) Prior tometaphase B) Anaphase C) Telophase D) Cytokinesis
43) Why is it so important that all of the chromosomes align on the metaphase plate during metaphase? A) This is the onlyplace in the cell where the cyclins and Cdks are located. B) If they cannot,it suggests that they aren't properly attached to the spindle microtubules, andthus won't separate properly during anaphase. C) This is thelocation where the chromosomes can become attached to the spindlemicrotubules. D) This allows astersto form. E) This allows sister chromatids toform.
44) If a cell was capable of bypassing metaphase and going directly from prometaphase to anaphase, what is the most likely consequence of this? A) The resulting daughter cells would not have a nuclear envelope. B) The resultingdaughter cells would have significantly different quantities of cytoplasmicmaterials. C) The resultingdaughter cells would have different numbers of chromosomes. D) The resultingdaughter cells would be completely normal.
45)
Animal cells typically achieve cytokinesis by: A) binary fission. B) forming a cell plate across the middle of the cell. C) forming a cleavage furrow that pinches the cell into two. D) chromosome condensation. E) chromosome elongation.
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46)
Plant cells typically achieve cytokinesis by: A) binary fission. B) forming a cell plate across the middle of the cell. C) forming a cleavage furrow that pinches the cell into two. D) chromosome condensation. E) chromosome elongation.
47) If a drug that inhibited transport from the trans face of the Golgi was applied to plant cells, which stage of the cell cycle would be directly affected? A) G2 B) S C) Metaphase D) Anaphase E) Cytokinesis
48)
The progress of the eukaryotic cell cycle is regulated primarily by what proteins? A) Cyclins B) Histoneproteins C) Condensins D) FtsZ
49)
At what checkpoint(s) does the cell arrest in response to DNA damage? A) G1/S B) G2/M C) spindle D) G1/S and G2/M E) G2/M and spindle
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50) You are examining the effect of maturation-promoting factor (MPF) in sea urchin cells, which have a diploid number of 36. If you fuse a dividing sea urchin cell with a G1 arrested oocyte, what would be the outcome? A) The G1 cell would enter mitosis, but would likely arrestat the spindle checkpoint because the chromosomes have not been properlyreplicated. B) The G1 cell would undergo mitosis and its daughter cells would each have 36 chromosomes. C) The G1 cell would undergo mitosis and its daughter cellswould each have 18 chromosomes. D) The G1 cell would first go through S phase and then mitosis. Its daughter cells would have 36 chromosomes.
51)
What time point represents G2?
A) 1 B) 2 C) 3 D) 4
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52) You are studying cell cycle progression in yeast cells. If you could prevent cdc2 from associating with the mitotic cyclin, the cells would: A) arrest in G1. B) arrest in G2. C) arrest in S. D) arrest inprometaphase. E) arrest inmetaphase.
53) You are studying cell cycle progression in an early frog embryo. If you were to inject a protein synthesis inhibitor into this cell during S phase, where do you predict the cell would arrest? A) G1 B) G2 C) Metaphase D) Telophase
54) In G2, there are typically high levels of the mitotic cyclin. Why is cdc2 not active during G2 if the mitotic cyclin is present? A) Cdc2 is alsoregulated by phosphorylation. B) Cdc2 does notbind to the mitotic cyclin. C) Cdc2 requiresubiquitination to be activated. D) Cdc2 also has tobind to cohesin to be activated.
55)
What is separase? A) A protein thatmarks a protein called securin for destruction. B) A protein that ispart of the cohesin complex. C) A protein thatdestroys cohesin through its protease activity. D) A protein thattargets the mitotic cyclin for degradation.
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56)
What is one of the roles of the APC/C during anaphase? A) Todirectly target the mitotic cyclins for destruction. B) To directlytarget cohesin for destruction. C) To directlytarget separase for destruction. D) To directlytarget microtubules for destruction.
57) What would you expect to happen if the anaphase-promoting complex/cyclosome (APC/C) failed to ubiquitinate securin? A) The cohesin complex will be destroyed, and the cell will remain in metaphase. B) The cohesin complex will persist, preventing the cell from entering anaphase. C) Separase will be marked for degradation by securin, preventing the cell from entering anaphase. D) Securin willremain intact and therefore will degrade cohesin, allowing the cell to enteranaphase.
58) If you were to think of the cell as a car, and mitosis as a process that drives that car to go, what would be a good analogy for a cell that has a mutation in both copies of a tumor-suppressor gene? A) The gas pedal of a car gets stuck while pushed down. B) The gas pedal of a car does not work at all. C) The brake pedal of a car gets stuck while pushed down. D) The brake pedal of a car does not work at all.
59) You are leading a team of researchers at a pharmaceutical company. Your goal is to design drugs that help fight cancer. Specifically, you want to focus on drugs that bind to and inactivate certain proteins, thereby halting cell cycle progression. One of your team members suggests targeting the retinoblastoma (Rb) protein and inhibiting this protein. Will this approach be successful? Why or why not?
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A) This approach will not be successful. Rb is tumor-suppressor protein, and functions to inhibit the action of a number of cell cycle regulatory proteins. A drug designed to inactivate the Rb protein would essentially create the same situation as in a cell that lacks both copies of the Rb gene. Lack of Rb activity would release the inhibition of cell cycle regulatory proteins, thereby promoting cell cycle progression, rather than halting it. B) This approachwill be successful. Rb is an oncogene, and functions to activate a number ofcell cycle regulatory proteins. A drug designed to inactivate the Rb proteinwould halt the cell cycle in cells that contain an active Rb. As aresult, cancer cells expressing a constitutively active Rb protein would begood targets for this type of therapeutic. C) This approach willbe successful. Rb is tumor-suppressor protein, and functions to inhibit theaction of a number of cell cycle regulatory proteins. A drug designed toinactivate the Rb protein would activate cell cycle inhibition. Lack of Rbactivity would therefore inhibit the cell cycle regulatory proteins. D) This approach will not be successful. Rb is an oncogene, and functions to activate a number of cell cycleregulatory proteins. A drug designed to inactivate the Rb protein wouldactually activate cell cycle progression. As a result, this drug wouldlikely make this situation worse for patients whose cancer cells contain mutantRb.
60) This protein or protein complex functions in the cell to stop cell division if the cell has experienced extensive DNA damage: A) APC/C B) p53 C) FtsZ D) Condensin
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Answer Key Test name: Chap 10_13e_Raven 1) A 2) B Both eukaryotic and prokaryotic chromosomes have to be tightly packed to fit into the cell, and the compaction process involves SMC proteins in both cases. Both eukaryotic and prokaryotic chromosomes are made up of double stranded DNA. Both eukaryotic and prokaryotic cells contain chromosomes, though the chromosomes are of different structures. 3) D 4) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about the role of FtsZ. • What type of thinking is required? o You are being asked to apply your knowledge of FtsZ to predict what would happen if it was mutated. • What key words does the question contain and what do they mean? o FtsZ mutation: when a mutation in a protein is discussed it can be assumed the mutation leads to a loss of function of that protein. Gather Content • What do you know about FtsZ? How does it relate to the question? o FtsZ is a protein found in a ring structure around the center of a bacterium. As this ring closes the cell splits into two new cells. Consider Possibilities • What other information is related to the question? Which information is most useful? o FtsZ is only found in bacteria so it is not involved in eukaryotic processes like cytokinesis, cohesin cleavage, or prophase. o FtsZ is not involved in DNA synthesis. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The best answer is that FtsZ is involved in pinching bacterial cells into two new cells through the formation of a ring around the center of the cell called a septum. This process is called septation and will be Version 1
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stopped if FtsZ activity is lost. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of the role of FtsZ in a bacterial cell to predict what would happen if it was mutated. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that FtsZ is found in the center of the cell? Did you remember that the septum contracts in seperation? 5) B Review Figure 10.6. 6) B The centromere is the point of constriction on the chromosome that contains repeated DNA sequences that bind specific proteins. The proteins that bind at the centromere are referred to as the kinetochore. The cohesin complex keeps the sister chromatids attached at the centromere, but the cohesin complex is a protein complex, and does not contain repeated DNA sequences. The centrosome is a microtubule organizing center that contains a pair of centrioles; these are not part of chromosomes. 7) B 8) D 9) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about a cell with 2n+1 chromosomes. • What type of thinking is required? o You are being asked to apply your knowledge of the normal number of chromosomes in a cell. • What key words does the question contain and what do they mean? o 2n+1: a diploid cell is 2n, so a cell with 2n+1 chromosomes has one extra chromosome. Gather Content • What do you know about the number of chromosomes in a human cell? How does it relate to the question? o The normal chromosome number for humans is 2n, where n = 23 for the number of different types of chromosomes each human cell contains. 2n + 1 indicates that the individual has the diploid number of chromosomes (i.e., 46) plus one additional chromosome. Consider Possibilities • What other information is related to the question? Which information is most useful? o Monosomy would be 2n - 1, because this refers to a condition where one chromosome is missing. o While cancer cells can sometimes gain or lose one or more chromosomes, this would not affect all the cells in the organism, just the cancerous cells. o This chromosome number is not relevant to obesity. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The presence of an extra chromosome in all cells indicates that this person most likely inherited an extra copy of one chromosome, which is how trisomy is defined. Therefore, this is most likely a case of trisomy. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of the number of chromosomes in a normal cell to define how an individual with 2n+1 chromosomes would be classified. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that 2n-1 was a trisomy and not a monosomy? Did you think that a 2n+1 number of chromosomes in all cells would contribute to cancer or obesity? 10) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about the amount of condensation of DNA in heterochromatin. • What type of thinking is required? o You are being asked to apply your knowledge of the effects of DNA condensation in heterochromatin on gene expression. • What key words does the question contain and what do they mean? o Heterochromatin: more highly condensed DNA. o TADs: anchored regions of chromatin that are looped. Gather Content • What do you know about gene expression? How does it relate to the question? o For a gene to be expressed, enzymes like RNA polymerase need access the DNA to synthesize RNA from the DNA template. Consider Possibilities • What other information is related to the question? Which information is most useful? o If a region of DNA is loosely condensed, these genes would be more likely to be expressed. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Since heterochromatin domains are not expressed, the DNA must be very tightly condensed in those regions. Version 1
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of gene expression to predict if heterochromatin is highly condensed. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that the genes located in heterochromatin are not expressed? Could you make the connection that the genes within condensed heterochromatin could not be accessed and expressed? 11) A 12) B 13) A 14) B 15) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about predicting the haploid number of chromosomes in a diploid cell. • What type of thinking is required? o You are being asked to apply your knowledge of somatic cells to calculate the number of chromosomes that would be in a haploid cell. • What key words does the question contain and what do they mean? o Somatic cell arrested in mitosis: this means it is a diploid cell in the mouse Gather Content • What do you know about diploid cells? How does it relate to the question? o The karyotype was done with somatic cells arrested in mitosis. The 40 chromosomes observed represents the diploid number (2n). Consider Possibilities • What other information is related to the question? Which information is most useful? o If there are 40 chromosomes in a diploid cell then 80 chromosomes would be tetraploid. 10 chromosomes would be one forth the number and would not occur naturally. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The haploid number (n) will be half the number of chromosomes Version 1
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observed in the diploid cell (2n). Therefore, the haploid number is 20. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the definitions of haploid and diploid to calculate the number of chromosomes in a haploid cell. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember the definitions of haploid and diploid? Did you recognize that the somatic cell was diploid? Did you know how to calculate the number of chromosomes in a haploid cell if you knew the number in a diploid cell? 16) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about sister chromatids. • What type of thinking is required? o You are being asked to apply your knowledge of sister chromatids and chromosomes to calculate the number of chromosomes in a haploid cell. • What key words does the question contain and what do they mean? o Sister chromatids: appear after DNA replication, where each chromosome contains two sister chromatids. Gather Content • What do you know about sister chromatids? How does it relate to the question? o If there are 32 sister chromatids and two per chromosome, that means that there are 16 chromosomes. Consider Possibilities • What other information is related to the question? Which information is most useful? o Since this is a normal somatic cell this number represents a diploid number. So the diploid number of chromosomes is 16. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Since this is a normal somatic cell, and the diploid number is 16, then the haploid number would be half of 16 or 8 chromosomes.
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the definition of sister chromatids to calculate the number of chromosomes in a haploid cell. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that there are two sister chromatids in a single chromosome? Did you realize that a normal somatic cell will be diploid? Did you know how to calculate the haploid number by dividing the diploid number by two? 17) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about sister chromatids. • What type of thinking is required? o You are being asked to apply the definition of sister chromatids to calculate the number of chromosomes in a cell. • What key words does the question contain and what do they mean? o Sister chromatids: after DNA replication, each chromosome contains two sister chromatids. Gather Content • What do you know about sister chromatids? How does it relate to the question? o If there are 32 sister chromatids and two per chromosome, that means that there are 16 chromosomes. Consider Possibilities • What other information is related to the question? Which information is most useful? o Since this is a normal somatic cell it is diploid. So the diploid number of chromosomes is 16. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Since this is a normal somatic cell, the diploid number will be 16. The 32 sister chromatids would consist of 16 chromosomes.
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply the definition of sister chromatids to predict the number of chromosomes in a diploid cell. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that there are two sister chromatids in a chromosome? Did you think that each sister chromatid was one chromosome? 18) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about the number of sister chromatids at G1. • What type of thinking is required? o You are being asked to apply your knowledge of the cell cycle to predict how many sister chromatids there are in G1. • What key words does the question contain and what do they mean? o G1 of the cell cycle: this is before the cell enters the cell cycle so the DNA has not yet replicated. o Sister chromatids: these form after the DNA is replicated in S phase but before they separate in mitosis. The two sister chromatids comprise of a single chromosome. Gather Content • What do you know about sister chromatids? How does it relate to the question? o Sister chromatids form after the DNA is replicated in S phase but before they separate in mitosis. Consider Possibilities • What other information is related to the question? Which information is most useful? o If a somatic cell contains 14 chromosomes, this will be the diploid number. The haploid number will be 7. A cell with 28 chromosomes would be tetraploid. Choose Answer • Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer? o Because the cell is still in G1 it would not have replicated its DNA and will have no sister chromatids. It does not matter how many chromosomes the cell has. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge of when chromosomes replicate to form sister chromatids. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that DNA replicates in S phase after G1? Did you think that the sister chromatids were present in G1? 19) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about the number of sister chromatids in G2. • What type of thinking is required? o You are being asked to apply your knowledge of the cell cycle to predict how many sister chromatids there are in G2. • What key words does the question contain and what do they mean? o G2 of the cell cycle: this is after the S phase of the cell cycle so the DNA has been replicated. o Sister chromatids: these form after the DNA is replicated in S phase but before they separate in mitosis. The two sister chromatids comprise of a single chromosome. Gather Content • What do you know about sister chromatids? How does it relate to the question? o Sister chromatids form after the DNA is replicated in S phase but before they separate in mitosis. Consider Possibilities • What other information is related to the question? Which information is most useful? o If a somatic cell contains 20 chromosomes, this will be the diploid number. The haploid number will be 10. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o Because the cell is in G2 it will have replicated its DNA and will have two sister chromatids per chromosome. Since there are 20 chromosomes there will be 40 sister chromatids. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge of when chromosomes replicate to form sister chromatids. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that DNA replicates in S phase before G2 so there would be two sister chromatids per chromosome? Did you think that the sister chromatids had already separated in mitosis which actually occurs after G2? 20) B 21) A During both G1 and G2 the cells are growing, but during G1, the cells do not contain a replicated genome. 22) E 23) C 24) B 25) B Plant cells are eukaryotic, and therefore the division of cytoplasm is referred to as cytokinesis 26) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the number of chromosomes following mitosis. • What type of thinking is required? o You are being asked to apply your knowledge of mitosis to predict the number of chromosomes a cell will have. • What key words does the question contain and what do they mean? o 32 chromosomes prior to S phase – this is the diploid number of chromosomes. o Mitosis and cytokinesis: after the chromosomes are replicated, they are divided evenly between the two daughter cells. Gather Content • What do you know about mitosis? How does it relate to the question? o In mitosis the chromosomes are replicated in S phase and then divide evenly into two daughter cells. o Before the S phase, the cell is diploid, so there are 32 chromosomes in this diploid cell. Consider Possibilities • What other information is related to the question? Which information is most useful? o If the diploid number is 32, then a cell with 64 chromosomes is tetraploid. A cell with 16 chromosomes is haploid. A cell with 8 chromosomes would not be able to survive. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If a diploid cell has 32 chromosomes and goes through mitosis, each of the new daughter cells would also be diploid and should have 32 chromosomes. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of mitosis to predict how many chromosomes daughter cells would have. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that the number of chromosomes in the daughter cells does not change following mitosis? Did you confuse mitosis and meiosis? Did you think that the number of chromosomes increase after mitosis? 27) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about the rate of cell division. • What type of thinking is required? o You are being asked to analyze several predictions about what would happen in the cell cycle was shortened. • What key words does the question contain and what do they mean? o Embryonic cell cycle is shorter – This means that the time from G1 through M is shorter. Gather Content • What do you know about the cell cycle? How does it relate to the question? o The cell cycle is made up of four phases; G1 and G2 are gaps where proteins and membranes are made for the newly dividing cells, S where DNA is replicated, and mitosis where the cells divide. o The question states that the replication of DNA and mitosis occurs at the normal rate. However the overall rate of the cell cycle is shorter. Consider Possibilities • What other information is related to the question? Which information is most useful? o For the daughter cells to survive, they must receive the same amount of DNA as the embryonic stem cell and to do so they need to be able to form a mitotic spindle. o The embryonic stem cells are going through mitosis so they cannot be in G0 all the time. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The embryonic stem cells have a shorter cell cycle, but S and mitosis occur at the same rate, so G1 and G2 must be shorter. As a result, the daughter cells will likely be smaller than the parent cell in the embryonic cell cycles. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze different predictions of what would happen in embryonic stem cells with shorter cell cycles. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that the cells could not be able to divide? Did you think that the daughter cells would not get as much DNA as the embryonic stem cells. 28) A 29) A 30) D Sister chromatids are held together by cohesin from the time they are synthesized in S phase until they enter anaphase and cohesin is cleaved by separase. 31) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about numbers of chromatids and individual DNA molecules. • What type of thinking is required? o You are being asked to apply your knowledge of chromosomes to predict the numbers of chromatids and DNA molecules after S phase. • What key words does the question contain and what do they mean? o Pairs of sister chromatids: formed after replication of the DNA and attached together to form a single chromosome. o Individual DNA molecules: separate double stranded DNA molecules. Gather Content • What do you know about sister chromatids? How does it relate to the question? o Sister chromatids form after a chromosome is replicated during S phase. For each initial chromosome there will now be a pair of sister chromatids. o Each pair of sister chromatids then contains two individual DNA molecules that were created from the single DNA molecule before replication in S phase. Consider Possibilities • What other information is related to the question? Which information is most useful? o A human cell starts with 46 chromosomes. These are then duplicated during S phase. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If a cell starts with 46 chromosomes and replicates, S phase will produce 46 pairs of sister chromatids. Each sister chromatid contains two strands of DNA so there will be 92 strands of DNA in total. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of sister chromatids to calculate how many would be in a human cell after S phase. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that a normal human cell has 46 chromosomes? Did you understand that each chromosome would produce two sister chromatids after its DNA was replicated? Did you realize that each sister chromatid was an individual DNA molecule? 32) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about the kinetochore complex. • What type of thinking is required? o You are being asked to apply your knowledge of the kinetochore complex to predict what would happen if a chromosome could not bind to it. • What key words does the question contain and what do they mean? o Kinteochore complex: a complex of proteins that allow a chromosome to bind to the mitotic spindle. Gather Content • What do you know about the kinetochore complex? How does it relate to the question? o It allows the chromosome to bind to the mitotic spindle. Consider Possibilities • What other information is related to the question? Which information is most useful? o Microtubules do not affect chromosome replication, condensation, or binding to histones. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Without being able to bind to the kinetochore complex, a chromosome cannot bind to the mitotic spindle.
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge of the function of the kinetochore complex. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that the kinetochore complex binds to the mitotic spindle? Did you think that it was involved in replication of the chromosome or binding to histones? 33) B 34) D 35) A 36) B 37) C 38) B 39) B 40) A 41) D 42) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about the role of microtubules in moving chromosomes during mitosis. • What type of thinking is required? o You are being asked to apply your understanding of how chromosomes move by the assembly and disassembly of microtubules to predict where taxol would arrest a cell in mitosis. • What key words does the question contain and what do they mean? *Taxol: stabilizes microtubules and prevents them from diassembling. *Microtubules: grow by adding molecules of tubulin and shrink by losing tubulin molecules. Gather Content • What do you know about movement of chromosomes in mitosis? How does it relate to the question? o Chromosomes move by being pushed and pulled by microtubules. If more tubulin is added to a microtubule, it will grow and push a chromosome that it is attached to. If tubulin is removed from a microtubule by disassembly, then any attached chromosome will be pulled. Consider Possibilities • What other information is related to the question? Which information is most useful? o In anaphase, telophase and cytokinesis the chromosomes are being pulled to either end of the cell. This will require disassembly of the tubulin molecules attached to the chromosome.
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Even though the later stages do require microtubule disassembly, the movement of the chromosome to the equator of the cell also requires some pushing and pulling. Thus, if taxol is added it will affect the assembly movement of the chromosomes before the later stages, and the cell will arrest before it gets to metaphase. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of how chromosomes move during mitosis to predict the effects of taxol. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that chromosomes needed to be pushed and pulled by the assembly and disassembly of microtubules to get them to the equator in metaphase? Did you think that pulling chromosomes only occurred in anaphase and later steps of mitosis? Did you realize that pulling chromosomes requires the disassembly of microtubules? 43) B 44) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about the role of metaphase. • What type of thinking is required? o You are being asked to analyze different explanations of what would happen to daughter cells if they skipped metaphase. • What key words does the question contain and what do they mean? o Metaphase: during metaphase the sister chromatids are attached to the mitotic spindle as they are moved to the equator of the cell. Gather Content • What do you know about metaphase? How does it relate to the question? o Metaphase is critical for ensuring that all sister chromatids are properly attached to the mitotic spindle. Consider Possibilities • What other information is related to the question? Which information is most useful? o Metaphase involves the movement of chromosomes to the center of the dividing cell. It does not affect formation of the nuclear envelope or movement of cytoplasm. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If this phase were bypassed that would mean that there was no mechanism to check for proper attachment to the mitotic spindle. As a Version 1
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result, it is possible that some chromosomes were not properly attached and therefore, some chromosomes may not properly separate and/or segregate. This would lead to daughter cells with different numbers of chromosomes, which is not the goal of mitosis. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze statements about what would happen to a cell if it skipped metaphase and divided. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that metaphase is where sister chromatids attach to the mitotic spindle? Did you understand that if the spindle does not attach properly that chromosomes will not segregate equally between the two daughter cells. Did you think that metaphase is where the nuclear envelope forms? Did you confuse metaphase and telophase where the cytoplasm separates into the two daughter cells? 45) C 46) B 47) E
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Clarify Question • What is the key concept addressed by the question? o The question asks about the role of the Golgi in a step in mitosis. • What type of thinking is required? o You are being asked to apply your knowledge of mitosis in a plant to explain the role of the Golgi. • What key words does the question contain and what do they mean? o A drug that inhibited transport from the trans face of the Golgi – this means that products of the Golgi could not be released. Gather Content • What do you know about the role of the Golgi in mitosis in plants? How does it relate to the question? o In plants, the cell plate forms from the fusion of Golgi-derived vesicles. . Consider Possibilities • What other information is related to the question? Which information is most useful? o S is where DNA synthesis occurs, and does not involve the Golgi. o Metaphase and anaphase involve the movement of chromosomes and do not require the Golgi. o G2 is a stage of the cell cycle that involves making components for the dividing cells. The Golgi could be involved in this process, but this would be a less important role in plants than the formation of the cell plate. Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The drug will prevent the building blocks of the cell plate from being released from the Golgi. As a result, cytokinesis is the most likely process to be affected directly by this drug. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of the role of the Golgi during mitosis in plants. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that the cell plate in plant cells arises from the Golgi? Did you think that anaphase and metaphase require the Golgi? Did you think that with the Golgi malfunctioning, the cell would arrest in G2? 48) A 49) D 50) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about the effect of maturation promotion factor on a cell in G1. • What type of thinking is required? o You are being asked to analyze different predictions of what would happen if a cell in G1 is fused to a rapidly dividing cell which would express MPF. • What key words does the question contain and what do they mean? o MPF: maturation promoting factor, a substance that triggers a cell to enter mitosis. o Cell arrested in G1: this cell will not have gone through the S phase yet, so its chromosomes will not be replicated. Gather Content • What do you know about MPF? How does it relate to the question? o MPF triggers a cell to enter mitosis. If a cell has not yet duplicated its chromosomes, then spindles will not form properly and the cell will not be able to divide. Consider Possibilities • What other information is related to the question? Which information is most useful? o While MPF will induce a cell to enter mitosis but not S phase, so if the DNA has not replicated then the cell will not be able to split the DNA into equal amounts between the two daughter cells. Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o In the presence of MPF the G1 cell would immediately enter mitosis. The nuclear envelope would break down, the spindle would assemble and chromosomes would move in the cell. But because the cell has not gone through S phase, the chromosomes have not be replicated, and thus the cell would likely arrest at the spindle checkpoint. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze several predictions of what would happen if a rapidly dividing cell was fused with a cell arrested in G1. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that MPF in the rapidly dividing cell would cause the cell arrested in G1 to immediately enter mitosis without going through S phase? Did you think that the cell would divide its existing chromosomes without going through S phase? Did you forget that the checkpoints would prevent cells from dividing if the spindles did not form properly? 51) C 52) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the effect on inhibiting a cdc2/mitotic cyclin complex. • What type of thinking is required? o You are being asked to apply your knowledge of cyclin/cdc2 interactions to predict what would happen if it was inhibited. • What key words does the question contain and what do they mean? o Prevent cdc2 from associating with the mitotic cyclin – cdc2 needs to associate with a cyclin to be active and allow the cell to enter mitosis. Gather Content • What do you know about cdc2/cyclin complexes? How does it relate to the question? o For a cdc2 kinase to be active it needs to bind to a cyclin. When it is active the cell will proceed to the next stage of the cell cycle. Consider Possibilities • What other information is related to the question? Which information is most useful? o Because the question specifies a mitotic cyclin, the cdc2/cyclin complex would normally allow the cell to enter mitosis. Without the complex formation the cell would not enter mitosis, so it could not arrest in a stage of mitosis like prometaphase or metaphase. Separate checkpoints and cyclins regulate movement of the cell through S and G1. Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Without a cdc2/mitotic cyclin complex the cell could not enter mitosis. G2 is the stage before mitosis, so the cell would be stuck in G2. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of the function of the cdc2/mitotic cyclin to predict what would happen if this complex could not form. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that the mitotic cyclin would allow the cell to enter mitosis when bound to cdc2? Did you realize that G2 is the stage before mitosis, so the cell would be stuck, or arrest, in G2 if this activity was blocked? 53) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the role of protein synthesis in cell cycle check points. • What type of thinking is required? o You are being asked to apply your knowledge of which proteins need to be synthesized for a cell to move through the cell cycle. • What key words does the question contain and what do they mean? o Protein synthesis inhibitor: a substance that prevents the synthesis of new protiens, including cyclins. Gather Content • What do you know about protein synthesis and the cell cycle? How does it relate to the question? o Cyclins need to be newly made for the cell to move through each stage of the cell cycle. If cyclins cannot be synthesized then the cell will be stuck in that stage of the cell cycle. Consider Possibilities • What other information is related to the question? Which information is most useful? o By adding the inhibitor in S phase, the cell will already have gone through the G1/S checkpoint. The next checkpoint is the G2/M checkpoint. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o Because the protein synthesis inhibitor is added during S phase, the next checkpoint is the G2/M checkpoint. Without newly made cyclin the cell will not be able to pass this checkpoint and will therefore become stuck in G2. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your understanding of the synthesis of cyclins to predict what would happen if protein synthesis is blocked. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that cells in S phase had already passed the G1/S check point? Did you remember that the G2/M checkpoint would be next? Did you understand that cyclins need to be synthesized for a cell to pass through each stage of the cell cycle? 54) A 55) C 56) A 57) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the role of securin in the cell cycle. • What type of thinking is required? o You are being asked to analyze several statements predicting what would happen in a cell if APC/C failed to ubiquitinate securin. • What key words does the question contain and what do they mean? o Ubiquitinate: when ubiquitin is added to a protein, that protein is targeted for degradation. Gather Content • What do you know about securin? How does it relate to the question? o Securin is an inhibitor of the enzyme separase. Separase will cleave the cohesin complex that holds sister chromatids together. Once cleaved, the sister chromatids can separate in anaphase. o APC/C ubiquitinates proteins and targets them for destruction. If it cannot ubiquitinate securin, then securin will remain active. Consider Possibilities • What other information is related to the question? Which information is most useful? o Securin is an inhibitor, not an enzyme, so it cannot degrade separase or cohesin. o The cohesin complex needs to be destroyed for the cell to enter anaphase, so its destruction would not cause the cell to remain in metaphase. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Securin is an inhibitor of the enzyme separase. Separase will cleave the cohesin complex that holds sister chromatids together. Once cleaved, the sister chromatids can separate in anaphase. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze several statements to choose which best explains what would happen if securin remained active in a cell. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you understand that ubiquitination of securin would lead to its destruction? Did you recall that securin is an inhibitor of separase, and if securin was not degraded separase would remain inactive? Did you predict that if separase remained inactive, cohesin would not be degraded and the sister chromatids could not separate allowing to cell to enter anaphase? 58) D Tumor suppressor genes are like the brakes on the cell cycle. Normally, they prevent cell division in response to problems, such as damaged DNA or incomplete replication. If both copies of a tumor suppressor gene are mutated, that would mean that a cell could not stop dividing in response to normal signals. This is analogous to cutting the brakes on a car. No matter what "signals" emerge (a stop sign, a red light, etc.), it is not possible to stop the car using the brake because there is something wrong with the brakes.
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59) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about the role of Rb in regulating the cell cycle. • What type of thinking is required? o You are being asked to analyze statements about the benefits of inhibiting Rb as a cancer therapy. • What key words does the question contain and what do they mean? o Rb: a tumor suppressor protien that normally halts the cell cycle. o Halting cell cycle progression: many drugs used to treat cancer do so by slowing down the cell cycle. Gather Content • What do you know about Rb? How does it relate to the question? o Rb is a tumor suppressor that halts the cell cycle. Mutations that block Rb activity lead to an increase in the cell cycle activity and possibly cancer. Consider Possibilities • What other information is related to the question? Which information is most useful? o Rb is not an oncogene, it is a tumor suppressor. o The researchers have proposed inhibiting the tumor suppressor Rb, which would have the same effect as mutations in Rb that lead to cancer. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The best answer is that this experiment would not be successful, Version 1
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because Rb is a tumor suppressor and you do not want not inactivate it to prevent cancer. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze several statements to see which best explains if an experiment would work. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that Rb was a tumor suppressor? Did you realize that inhibiting a tumor suppressor would actually increase the risk of cancer? 60) B
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Chapter 11 13e CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 1) Which cells never divide by meiosis? (Check all that apply) A) Haploid cells B) Diploid cells C) Somatic cells D) Germ-line cells E) Zygotes
2) A cell biologist examines a skin cell from a lizard during metaphase of mitosis and determines that 20chromatids are present. The role of meiosis in this species is to (Check all that apply) A) Produce 4 daughter cells that are genetically different from each other. B) Produce 4 daughter cells that are genetically different from the original parental cell. C) Reduce the number of chromosomes per cell from 10 to 5. D) Reduce the number of chromosomes per cell from 20 to 10.
3) A cell biologist examines a leaf cell from an alfalfa plant during metaphase of mitosis and determines that 32chromatids are present. The role of fertilization in this species is to (Check all that apply) A) produce a new cell that has a combination of chromosomes from 2 different parents. B) increase the number of chromosomes per cell from 16 to 32. C) increase the number of chromosomes per cell from 8 to 16. D) combine the chromosomes from 2 haploid cells into a single diploid cell.
4) Sister chromatids move to opposite poles of the cell during_________blank. (Check all that apply)
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A) anaphase I ofmeiosis B) metaphase I ofmeiosis C) anaphase II ofmeiosis D) anaphase ofmitosis
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 5) Edouard van Beneden proposed that an egg and a sperm, each containing half the complement of chromosomes found in somatic cells, fuse to produce a single cell called a(n)_________blank. A) zygote B) karyotype C) embryo D) oocyte
6) _________blank is a process of nuclear division that reduces the number of chromosomes per cell from 2 sets to 1 set. A) Mitosis B) Meiosis C) Binary fission D) Syngamy
7)
_________blank cells contain one set of chromosomes. A) Germ-line B) Somatic C) Diploid D) Haploid
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8) In life cycles that alternate between haploid and diploid stages, fertilization doubles the number of chromosomes per cell while_________blank reduces it in half. A) mitosis B) meiosis C) binary fission D) syngamy
9) Homologous chromosomes pair along their length during prophase I of meiosis. While two homologues are paired, genetic exchange may occur between them in a process called_________blank . A) syngamy B) synapsis C) independentassortment D) crossing over
10)
Compared to asexual reproduction, the main advantage of sexual reproduction is that it A) requires less energy. B) increases the genetic diversity of the offspring. C) can produce more complex offspring. D) can produce a greater number of offspring.
11) If there were no suppression of DNA replication between meiotic divisions and cytokinesis proceeded normally, what is the most likely outcome of meiosis? A) 4diploid cells B) 2 diploidcells C) 4 haploidcells D) 2 haploidcells E) 2 diploid cells and 2 haploid cells
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12) Evidence of crossing over can often be seen under the light microscope as a structure called a_________blank . A) kinetochore B) centromere C) chiasma D) centriole
13)
The fusion of a male gamete with a female gamete is called A) syngamy. B) meiosis. C) mitosis. D) recombination. E) synapsis.
14) Diploid organisms use meiosis to produce haploid cells. Meiosis consists of how many rounds of nuclear division? A) One B) Two C) Three D) Four E) None of these
15) The pairing of chromosomes along their lengths, which is essential for crossing over, is referred to as
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A) syngamy. B) synapsis. C) prophase. D) recombination. E) centromere.
16)
The cell produced by the fusion of an egg and a sperm is the A) gamete. B) oocyte. C) zygote. D) germ line cell. E) somatic cell.
17)
The zygote has A) one copy of each chromosome. B) one full haploidcomplement of chromosomes. C) chromosomes identical to those of a sperm cell. D) chromosomes identical to those of an egg cell. E) two copies of each chromosome.
18)
All animal cells are diploid except A) gametes. B) muscle cells. C) nerve cells. D) germ-linecells. E) somaticcells.
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19) The point of connection between two sister chromatids, before anaphase II of meiosis separates them, is called the A) centriole. B) kinetochore. C) centromere. D) spindleapparatus. E) centrosome.
20) cell?
Which of the following produces new cells that are genetically identical to the original
A) Meiosis B) Mitosis C) Crossing over D) Independent assortment E) Fertilization
21) In animals, the cells that will eventually undergo meiosis to produce gametes are set aside early in development. These are called A) somaticcells. B) germ-linecells. C) sex cells. D) gametophytes. E) reproductivecells.
22)
Which of the following events occurs first during meiosis?
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A) Homologous chromosomes separate and are pulled to opposite poles of the cell B) Sister chromatids separate and are pulled to opposite poles of the cell C) Chromosomes decondense D) Synapsis of homologous chromosomes E) Pairs of homologous chromosomes align along the equatorial plate
23)
Chromosomes exchange genetic information by A) fertilization. B) mitosis. C) syngamy. D) DNA replication. E) crossing over.
24)
Crossing over between homologous chromosomes takes place during A) prophase II. B) prophase I. C) interphase II. D) interphase I. E) metaphase II.
25)
The synaptonemal complex is A) a cluster ofmicrotubules at each pole of the cell. B) a network ofmicrotubules that forms the spindle apparatus. C) a network ofproteins that holds homologues together. D) the area wheremicrotubules attach to the centromere of each chromosome. E) a region ofhighly coiled DNA.
26)
At the end of meiosis II, each of the four resulting cells contains
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A) one full set ofchromosomes, each with 2 molecules of DNA. B) two full sets ofchromosomes, each with 2 molecules of DNA. C) one full set ofchromosomes, each with 1 molecule of DNA. D) two full sets ofchromosomes, each with 1 molecule of DNA.
27)
Which best describes the process of independent assortment?
A) The way one pair ofhomologues lines up along the metaphase plate does not affect how any otherpair lines up. B) Segregation ofchromosomes during meiosis I is independent of their segregation during meiosisII. C) During synapsis,chromosomes pair up at random. D) Crossing overalong one pair of chromosomes is independent of crossing over along the otherpairs. E) During synapsis,homologues pair independently of each other.
28)
In plants and animals, the zygote develops by which of the following processes? A) Mitosis B) Meiosis C) Syngamy D) Synapsis E) Reduction division
29)
The pairing of homologous chromosomes is called A) syngamy. B) synapsis. C) alignment. D) independentassortment. E) crossing over.
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30)
Which best explains a component of meiosis?
A) The cells thatresult from meiosis I are haploid, and each chromosome consists of 1chromatid. B) The cells thatresult from meiosis I are haploid, and each chromosome consists of 2chromatids. C) The cells thatresult from meiosis II are haploid, and each chromosome consists of 2chromatids. D) The cells thatresult from meiosis I are diploid, and each chromosome consists of 2chromatids. E) The cells thatresult from meiosis I are diploid, and each chromosome consists of 1chromatid.
31)
During meiosis, sister chromatids are held together by A) a commoncentromere and kinetochore microtubules. B) a commoncentromere and chiasmata. C) a commoncentromere and polar microtubules. D) a commoncentromere and a protein called cohesion. E) the kinetochoresand a protein called cohesion.
32)
What immediately follows meiosis I? A) DNAreplication B) Prophase II C) Metaphase II D) Synapsis of homologues E) Crossing over of homologues
33)
All of the following increase genetic variation EXCEPT
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A) crossing over. B) random fertilization. C) independent assortment. D) mitosis. E) mutation.
34) The term for one of a pair of chromosomes with similar genetic information and from different sources like the sperm and egg is_________blank . A) chiasma B) homologue C) kinetochore D) synapsis E) synaptonemal
35)
Which structures indicate where crossing over has occurred? A) Chiasmata B) Centromeres C) Kinetochores D) Centrioles E) Spindle fibers
36)
Which structure holds two homologous chromosomes together? A) Centromere B) Kinetochore C) Polar microtubules D) Spindle apparatus E) Synaptonemal complex
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37) During anaphase I, which best represents segregation of the chromatids that make up one pair of homologues? (M represents a maternal chromatid and P represents a paternal chromatid. Assume no crossing over occurs.) A) M and M to one pole; P and P to the other pole. B) M and P to one pole; M and P to the other pole. C) M to one pole; Pto the other pole. D) half of M and half of P to each pole. E) the segregation of these chromatids is completely random.
38) You are studying meiosis in an organism where 2n = 24. How many chromosomes will each nucleus have after meiosis II is complete? A) 24 B) 12 C) 6 D) 48
39) You are studying meiosis in an organism where 2n = 28. How many chromosomes will be present in each cell after meiosis I is complete but before meiosis II begins? A) 7 B) 14 C) 28 D) 56
40) You are comparing the events of meiosis I in cells from several different organisms. You come across one species in which you do not observe any chiasmata. The best conclusion to make is
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A) there is no crossing over between non sister chromatids. B) kinetochores of sister chromatids do not fuse. C) the chromosome pairs will not assort independently. D) chiasmata will form during meiosis II.
41)
Which statement about the reductive division of meiosis is false?
A) During thereductive division, homologues migrate to opposite poles of the cell. B) During thereductive division, sister chromatids migrate to opposite poles of thecell. C) During thereductive division, centromeres do not divide. D) At the end of thereductive division, each daughter nucleus has one-half as many centromeres asthe parental nucleus.
42) The Rec8 protein holds sister chromatids together during meiosis. If an individual has a mutation that prevents degradation of Rec8, this would most likely prevent A) normal segregation during meiosis I. B) normal segregation during meiosis II. C) synapsis of homologous chromosomes. D) crossing over during prophase I.
43) Which of the following is likely to occur if you were to prevent cyclin B from associating with its cyclin-dependent kinase near the end of meiosis I? A) Failure to maintain sister chromatid cohesion at the centromere B) Failure to form initiation complexes necessary for DNA replication to proceed C) Suppression of DNA replication D) Activation of DNA replication
44)
Which of the following statements about crossing over is false?
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A) Crossing over takes place between homologous chromosomes. B) Crossing over takes place between sister chromatids. C) Crossing overoccurs during prophase I. D) Sites of crossing over are called chiasmata. E) Crossing over is also called geneticrecombination.
45) In 95% of cases of Down's syndrome, there is one extra chromosome (number 21) in every cell. This aneuploid condition is most likely the result of A) failure to suppress DNA replication between meiosis I and meiosis II. B) failure of the chromosomes to assort independently during meiosis. C) failure of 1 homologous pair to segregate during meiosis. D) failure of 2 homologous pairs to segregate during meiosis. E) failure of the cytoplasm to divide at the end of meiosis II.
46)
Why does sexual reproduction require both meiosis and syngamy?
A) The process of meiosis results in the production of gametes in which the number of chromosomes remains the same. During syngamy, two gametes fuse to form a new cell, and after crossing-over only the chromosomes from one gamete persist. Therefore, by coupling meiosis and syngamy, the organism ensures that the proper number of chromosomes will be maintained. B) The process of meiosis results in the production of gametes in which the number of chromosomes is reduced by half. During syngamy, two gametes fuse to form a new cell, and the number of chromosomes is restored to the full amount. Therefore, by coupling meiosis and syngamy, the organism ensures that the proper number of chromosomes will be maintained. C) The process of meiosis results in the production of gametes in which the number of chromosomes is doubled. During syngamy, gametes are reduced by half, and the number of chromosomes is restored to the full amount. Therefore, by coupling meiosis and syngamy, the organism ensures that the proper number of chromosomes will be maintained.
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47) The most common form of gene therapy involves inserting a normal gene into cells that contain a defective version of the gene. In order to use gene therapy to prevent a man from passing a defective gene on to future generations, you should try to insert normal copies of the gene into A) blood cells. B) germ-line cells. C) somatic cells in the testes. D) bone marrow cells.
48) A geneticist examines a somatic cell from a fly during metaphase of mitosis and determines that 16 chromatids are present. If a germ-line cell from this species divides by meiosis, then at the end of meiosis I (including the first cytokinesis) each cell will contain A) 8 chromosomes with 8 DNA molecules. B) 8 chromosomes with 16 DNA molecules. C) 4 chromosomes with 4 DNA molecules. D) 4 chromosomes with 8 DNA molecules.
49) Non-disjunction is the failure of homologous chromosomes to separate during meiosis I, or the failure of sister chromatids to separate during meiosis II or mitosis. As a result, both homologous chromosomes or both sister chromatids migrate to the same pole of the cell. This produces daughter cells with an imbalance of chromosomes. A cell biologist examines the final products of meiosis in an earthworm (2n=36) and finds 2 cells with 20 chromosomes, and 2 cells with 16 chromosomes. Most likely this was because A) 2 pairs of sister chromatids failed to separate during meiosis II. B) 1 pair of sister chromatids failed to separate during meiosis II. C) 2 pairs of homologous chromosomes failed to separate during meiosis I. D) 1 pair of homologous chromosomes failed to separate during meiosis I.
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50) Non-disjunction is the failure of homologous chromosomes to separate during meiosis I, or the failure of sister chromatids to separate during meiosis II or mitosis. As a result, both homologous chromosomes or both sister chromatids migrate to the same pole of the cell. This produces daughter cells with an imbalance of chromosomes. If 18 pairs of sister chromatids segregate normally during meiosis II in cats (n=19) but we have non-disjunction of 1 pair, then at the end of meiosis II we will have A) 3 cells with 20 chromosomes and 1 cell with 18. B) 2 cells with 20 chromosomes and 2 cells with 18. C) 2 cells with 19 chromosomes, 1 with 20, and 1 with 18. D) 3 cells with 18 chromosomes and 1 cell with 20.
51) Meiosis results in a reassortment of maternal chromosomes (inherited from the mother) and paternal chromosomes (inherited from the father). If n=4 for a given species, and ignoring the effects of crossing over, what is the probability that a gamete will receive only paternal chromosomes? A) 1/2 B) 1/4 C) 1/8 D) 1/16
52) A cell in G2 before meiosis begins, compared with one of the four cells produced at the end of meiosis II, has A) twice as much DNA and twice as many chromosomes. B) four times as much DNA and twice as many chromosomes. C) twice as much DNA but the same number of chromosomes. D) four times as much DNA and four times as many chromosomes. E) twice as much DNA and half as many chromosomes.
53) In meiosis, sister kinetochores are attached to the same pole of the cell during meiosis I, and sister chromatid cohesion is released during anaphase II. What would be the likely result if sister kinetochores were attached to different poles of the cell during meiosis I and sister chromatid cohesion was released during anaphase I? Version 1
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A) Sister chromatids would migrate to opposite poles during anaphase I. B) Sister chromatids would migrate to opposite poles during anaphase II. C) Sister chromatids would migrate to the same pole during anaphase I. D) Sister chromatids would migrate to the same pole during anaphase II.
FILL IN THE BLANK. Write the word or phrase that best completes each statement or answers the question. 54) If a germ-line cell from an owl contains 8 picograms of DNA during of interphase, how many picograms of DNA would be present in each cell during prophase I of meiosis? (Enter the number only, not the units)
55) If a somatic cell from a cat contains 40 picograms of DNA during of interphase, how many picograms of DNA would be present in each cell during metaphase II of meiosis? (Enter the number only, not the units)
56) If a germ-line cell from a salamander contains 10 picograms of DNA during of interphase, how many picograms of DNA would be present in each gamete produced by this species? (Enter the number only, not the units)
57) How many tetrads are present in a single elephant cell (2n = 56) during metaphase I of meiosis?
58) A cell biologist examines a diploid cell from a particular species ofRhagoletis during metaphase of mitosis and determines that 8 centromeres are present. Based on this finding, how many centromeres should be present in a single cell from this species during anaphase II of meiosis?
59) A cell biologist examines a diploid cell from a particular species of butterfly during prometaphase of mitosis and determines that 10 centromeres are present. Based on this finding, how many chromatids should be present in a single cell from this species in metaphase I of meiosis? Version 1
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Answer Key Test name: Chap 11_13e_Raven 1) [A, C, E] 2) [A, B, C]
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Clarify Question ● What is the key concept addressed by the question?● The question asks about the number of chromosomes in mitosis and meiosis. ● What type of thinking is required?● You are being asked to use your knowledge of mitosis and meiosis to analyze statements about the products of meiosis. ● What keywords does the question contain and what do they mean?● 20 chromatids in metaphase of mitosis – after replication of DNA during the S phase each chromosome now contains two attached sister chromatids. Gather Content ● What do you know about meiosis? How does it relate to the question?● If there are 20 chromatids in a cell, this means the diploid cell has 10 chromosomes. ● These will separate during meiosis to form gametes that are haploid, each containing 5 chromosomes. Consider Possibilities ● What other information is related to the question? Which information is most useful?● The diploid cell has 10 chromosomes, so it cannot decrease from 20 to 10 chromosomes. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Due to independent assortment and crossing over these gametes will be genetically different from each other. Because the gametes are haploid and the parental cell is diploid these cells will also be genetically different from each other. Version 1
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● Because the parental cell has 10 chromosomes, after meiosis it will be haploid with 5 chromosomes. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to analyze statements about meiosis and choose which are correct. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that a cell with 20 chromatids would have 10 chromosomes? Did you realize that after meiosis the gametes would be genetically distinct from each other and from the parental diploid cell? 3) [A, C, D]
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Clarify Question ● What is the key concept addressed by the question?● The question asks about what happens during fertilization ● What type of thinking is required?● You are being asked to analyze statements about fertilization to choose which is correct. ● What key words does the question contain and what do they mean?● 32 chromatids in metaphase of mitosis – after replication of DNA during S phase each chromosome now contains two attached sister chromatids. Gather Content ● What do you know about fertilization? How does it relate to the question?● In fertilization two haploid gametes fuse to form a diploid fertilized egg. ● If a cell has 32 chromatids, these chromatids are paired as a chromosome. So the diploid number for this cell will be 16 chromosomes. If this cell goes through meiosis forming haploid gametes, each gamete will have 8 chromosomes Consider Possibilities ● What other information is related to the question? Which information is most useful?● In fertilization two haploid gametes fuse to form a diploid cell. In this case the haploid gametes each have 8 chromosomes, so they could not fuse to form a cell with 32 chromosomes. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● In this case the fusion of haploid gametes, each with 8 chromosomes, would form a cell with 16 chromosomes. Version 1
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● Because these gametes contain chromosomes from two different individuals, the chromosomes in the fertilized cell will be a combination of those from the two different parents. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to analyze statements about fertilization to explain properties of the cell that is formed. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that if a cell has 32 chromatids its diploid number is 16 chromosomes? Could you calculate that the haploid gametes would have half the number of chromosomes or 8? Did you understand that during fertilization two haploid gametes fuse to form a diploid cell containing 16 chromosomes that would be combined from two different parents? 4) [C, D] 5) A 6) B 7) D 8) B 9) D 10) B 11) A 12) C 13) A 14) B 15) B 16) C 17) E Version 1
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18) A 19) C 20) B 21) B 22) D 23) E 24) B 25) C 26) C 27) A 28) A 29) B 30) B 31) D 32) B 33) D 34) B 35) A 36) E 37) A 38) B
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Clarify Question ● What is the key concept addressed by the question?● The question asks about the number of chromosomes in a cell after meiosis. ● What type of thinking is required?● You are being asked to apply your knowledge of meiosis to predict the number of chromosomes in a cell. ● What keywords does the question contain and what do they mean?● An organism where 2n=24. This means that the haploid cells formed after meiosis will have 12 chromosomes. Gather Content ● What do you know about meiosis? How does it relate to the question?● In meiosis there are two stages, in meiosis I the chromosome pairs line up on the equator and separate. Then in meiosis II the sister chromatids separate. Consider Possibilities ● What other information is related to the question? Which information is most useful?● If the 2n=24 in a cell, then the only two possible answers are n=12 or 2n=24 for haploid or diploid cells, respectively. If a cell had 6 chromosomes that would be less than half the chromosomes of a haploid cell. If a cell had 48 chromosomes the cell would be tetraploid. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● If a cell going into meiosis has 24 chromosomes, these will form 12 pairs that line up during meiosis I and separate, forming two cells each with 12 chromosomes. After meiosis II the sister chromatids would separate Version 1
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forming four cells that are each haploid still with 12 chromosomes. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to apply your understanding of meiosis to predict how many chromosomes would be in a cell after meiosis II. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that meiosis forms haploid cells? Did you confuse meiosis with mitosis and think that meiosis forms diploid cells? 39) B
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Clarify Question ● What is the key concept addressed by the question?● The question asks about the number of chromosomes present after meiosis I. ● What type of thinking is required?● You are being asked to apply your knowledge of meiosis to calculate how many chromosomes will be in a cell after meiosis I. ● What keywords does the question contain and what do they mean?● An organism where 2n=28. This means that the haploid cells formed after meiosis will have 14 chromosomes. ● After meiosis I – in meiosis I the chromosome pairs line up on the equator and separate. ● Before meiosis II – in meiosis II the sister chromatids separate. Gather Content ● What do you know about meiosis? How does it relate to the question?● In meiosis there are two stages, in meiosis I the chromosome pairs line up on the equator and separate. Then in meiosis II the sister chromatids separate. Consider Possibilities ● What other information is related to the question? Which information is most useful?● If the 2n=28 in a cell, then the only two possible answers are n=14 or 2n=28 for haploid or diploid cells, respectively. If a cell had 7 chromosomes that would be less than half the chromosomes of a haploid cell. If a cell had 56 chromosomes the cell would be tetraploid. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● If a Version 1
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cell going into meiosis has 28 chromosomes, these will form 14 pairs that line up during meiosis I and separate, forming two cells each with 14 chromosomes. After meiosis II the sister chromatids would separate forming four cells that are each haploid. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to apply your understanding of meiosis to predict how many chromosomes would be in a cell after meiosis I. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that the chromosome pairs separated during meiosis I? Did you think that the chromosome with two sister chromatids was actually two separate chromosomes? 40) A 41) B 42) B
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Clarify Question ● What is the key concept addressed by the question?● The question asks about the role of Rec8 on chromatid separation. ● What type of thinking is required?● You are being asked to apply your knowledge of chromatids to predict what would happen if they could not separate. ● What keywords does the question contain and what do they mean?● Rec8 protein holds sister chromatids together – Rec8 is part of the cohesin that holds sister chromatids together. It needs to be degraded to allow sister chromatids to separate in anaphase II of meiosis Gather Content ● What do you know about meiosis? How does it relate to the question?● In meiosis there are two stages, in meiosis I the chromosome pairs line up on the equator and separate. Then in meiosis II the sister chromatids separate. Consider Possibilities ● What other information is related to the question? Which information is most useful?● If the sister chromatids cannot separate this would happen in meiosis II and not meiosis I. ● Rec8 is part of cohesin, it won’t be involved in crossing over or synapsis. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● The best answer is that without being able to degrade Rec8 and cohesin the chromosomes will not be able to segregate normally during meiosis II.
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to apply your understanding of the role of Rec8 and cohesin to predict what would happen if it was inhibited during meiosis. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that Rec8 was part of cohesin and holds sister chromatids together until it is degraded in meiosis II? Did you think that the sister chromatids separate in meiosis I? Did you think that Rec8 was involved in crossing over or the synapse instead of being part of cohesin? 43) D
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Clarify Question ● What is the key concept addressed by the question?● The question asks about the effect of loss of cyclin on kinase activity. ● What type of thinking is required?● You are being asked to analyze several statements that predict what would happen if a cyclin cannot bind a kinase. ● What keywords does the question contain and what do they mean?● Cyclin B associating with its cyclin-dependent kinase – when cyclin B binds its kinase the kinase is active and the cell will progress to the next checkpoint in the cell cycle. For the cell to progress further, the cyclin needs to be degraded. Gather Content ● What do you know about cyclins and cell checkpoints? How does it relate to the question?● There are three main checkpoints in the cell cycle: G1/S, G2/M, and one mitosis/meiosis to check for proper spindle formation. Cyclins need to be degraded and stop binding to their associated kinase for the cell to progress through the next checkpoint. Consider Possibilities ● What other information is related to the question? Which information is most useful?● During mitosis, the destruction of mitotic cyclin is necessary for a cell to enter another division cycle. The result of this maintenance of cyclin B between meiotic divisions in germ-line cells is the failure to form initiation complexes necessary for DNA replication to proceed. This failure to form initiation complexes appears to be critical to suppressing DNA replication. Choose Answer ● Given what you now know, what information and/or problemVersion 1
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solving approach is most likely to produce the correct answer?● Since cyclin B suppresses a cell from replicating DNA, loss of cyclin B would lead to an increase in DNA replication. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to analyze different statements explaining what would happen if cyclin B was inhibited in a cell. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that cyclin B needs to be degraded for a cell to replicate DNA? Did you realize that cyclin B would not affect the steps in chromosome separation of meiosis? 44) B 45) C
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Clarify Question ● What is the key concept addressed by the question?● The question asks about origin of a trisomy. ● What type of thinking is required?● You are being asked to apply your knowledge of meiosis to predict when a third copy of a chromosome would occur. ● What key words does the question contain and what do they mean?● One extra chromosome in every cell – this means that the addition of the extra chromosome must have happened early in meiosis so that a gamete would contain an extra chromosome 21. Gather Content ● What do you know about meiosis? How does it relate to the question?● During meiosis chromosome pairs separate during meiosis I. If these do not segregate then a daughter cell would get an extra chromosome. Consider Possibilities ● What other information is related to the question? Which information is most useful?● The presence of an extra chromosome is due to a problem with segregation, not DNA replication or independent assortment, which would affect more than one chromosome. ● If two homologous pairs of chromosomes did not segregate, one daughter cell would end up with two extra chromosomes. ● The division of cytoplasm will not affect the number of chromosomes in a cell. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer? ● The Version 1
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best answer is that if one pair of chromosome does not segregate during meiosis then one daughter cell will obtain two copies of that chromosome. When this gamete fuses with a normal gamete that contains one copy of each chromosome there will be three copies of that chromosome. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to apply your understanding of meiosis to explain how a trisomy arises. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that homologous chromosome pairs separate during meiosis? Did you understand that if this separation does not happen one gamete will end up with an extra copy of that chromosome while the other will have no chromosome? 46) B 47) B
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Clarify Question ● What is the key concept addressed by the question?● The question asks about the transfer of genetic information to the next generation. ● What type of thinking is required?● You are being asked to apply your knowledge of fertilization to explain which types of cells produce gametes. ● What key words does the question contain and what do they mean?● You are being asked to apply your knowledge of fertilization to explain which types of cells produce gametes. ● Passing a defective gene on to future generations – gametes are used to transfer genetic material from one generation to the next. Gather Content ● What do you know about fertilization? How does it relate to the question?● Gametes pass genetic information from one generation to the next. If you want to correct a defective gene so it cannot be passed on, it would need to be done in gametes. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Gametes are produced by meiosis in specific cells in the body. This does not happen in somatic cells like blood cells, bone marrow cells, or even the somatic cells of the reproductive organs. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● Gametes are produced in germ-line cells in the testes and ovaries. If gene therapy is done on these cells, the gametes they produce would contain the fixed Version 1
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gene and this would be passed on to future generations. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to apply your understanding of gamete production to predict which cells would pass genetic changes on to the next generation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that germ-line cells produce gametes? Did you realize that the changes would need to be made in the gametes to be passed on to the next generation? Did you think that changes in somatic cells like blood and bone marrow cells could be passed on to the next generation? 48) D
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Clarify Question ● What is the key concept addressed by the question?● The question asks about the number of chromosomes present in a cell after meiosis I. ● What type of thinking is required?● You are being asked to calculate the number of chromosomes present in a cell after meiosis. ● What key words does the question contain and what do they mean?● A cell in metaphase of mitosis has 16 chromatids – there are two chromatids in a chromosome after going through S phase. Gather Content ● What do you know about meiosis? How does it relate to the question?● If a diploid cell has 16 chromatids, there will be 8 pairs of sister chromatids each comprising a chromosome. ● In meiosis I chromosome pairs align and then separate. So after meiosis I the cells will be diploid, containing one copy of each chromosome. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Each chromosome after meiosis I consists of two sister chromatids. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● If the cell has 16 chromatids during metaphase of mitosis, the diploid number of the cell is 8 chromosomes. After meiosis I the cells will now be haploid with 4 chromosomes. ● In metaphase I of meiosis, the chromosome pairs each align. As each chromosome contains a pair of sister chromatids, this forms a tetrad. Version 1
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After meiosis I the cells will be haploid, but each chromosome will contain two chromatids. So for each chromosome there will be two DNA molecules, meaning the 4 chromosomes will consist of 8 DNA molecules. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to analyze a problem to calculate the number of chromosomes and DNA molecules in a cell after meiosis I. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you understand that the diploid number would be 8 chromosomes? Could you calculate that after meiosis I the cell would now be haploid with 4 chromosomes? Did you understand that each chromosome would contain 2 sister chromatids, meaning the cell has 8 DNA molecules? 49) C
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Clarify Question ● What is the key concept addressed by the question?● The question asks about the effect of non-disjunction on the number of chromosomes in a gamete. ● What type of thinking is required?● You are being asked to analyze different statements about non-disjunction to explain how many chromosomes would be present in a gamete. ● What keywords does the question contain and what do they mean?● (2n=36) and finds 2 cells with 20 chromosomes, and 2 cells with 16 chromosomes – If a cell has 2n=36, then n=18. The haploid cells produced have either 20 or 16 chromosomes, so plus or minus 2 chromosomes. Gather Content ● What do you know about non-disjunction? How does it relate to the question?● In non-disjunction, chromosomes fail to segregate, leading to gametes with extra or missing chromosomes. If n=18 and the haploid gametes have either 16 or 20 chromosomes, then both cells either gained or lost two additional chromosomes. Consider Possibilities ● What other information is related to the question? Which information is most useful?● If the non-disjunction happens during meiosis I, the two daughter cells will have either missing or extra chromosomes. When these daughter cells go through the second division in meiosis II both of their daughter cells would inherit the same number of chromosomes. So the four daughter cells would all contain extra or missing chromosomes. ● If the non-disjunction happens during meiosis II, one of the original Version 1
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daughter cells will divide normally producing two new daughter cells with the correct number of chromosomes. The cell that goes through non-disjunction will produce two daughter cells with abnormal chromosomes. So in this case two gametes would end up with a normal number of chromosomes and two would have extra or missing chromosomes. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Because the original diploid cell contains (2n=36), the haploid cell would end up with 18 chromosomes. Because there are 2 cells with 20 chromosomes, and 2 cells with 16 chromosomes the non-disjunction must have happened in the first round of meiosis. Non-disjunction would have led to two cells, one with 20 chromosomes and one with 16, each chromosome made of two sister chromatids. In meiosis II the two cells would divide again producing two haploid cells with 20 chromosomes and two with 16 chromosomes. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to analyze the results of an experiment to predict when non-disjunction occurred. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall if non-disjunction occurs in the first round of meiosis I the two daughter cells would then divide producing identical gametes? Did you realize that if non-disjunction occurred in meiosis II that one daughter cell would produce two gametes with the correct number of chromosomes and the second undergoing non-disjunction would Version 1
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produce gametes with extra or missing chromosomes? 50) C
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Clarify Question ● What is the key concept addressed by the question?● The question asks about the effect of non-disjunction on the number of chromosomes in a gamete. ● What type of thinking is required?● You are being asked to analyze different statements about non-disjunction to explain how many chromosomes would be present in a gamete. ● What keywords does the question contain and what do they mean?● If 18 pairs of sister chromatids segregate normally during meiosis II in cats (n=19) but we have non-disjunction of 1 pair – if n=19 and only 18 pairs of sister chromatids segregate normally then one pair must go through non-disjunction leading to extra or missing chromosomes. Gather Content ● What do you know about non-disjunction? How does it relate to the question?● In non-disjunction, chromosomes fail to segregate, leading to gametes with extra or missing chromosomes. If n=19 then a normally segregating cell would have 19 chromosomes and those with an extra or missing chromosome would have 20 or 18 chromosomes, respectively. Consider Possibilities ● What other information is related to the question? Which information is most useful?● If the non-disjunction happens during meiosis I, the two daughter cells will have either missing or extra chromosomes. When these daughter cells go through the second division in meiosis II both of their daughter cells would inherit the same number of chromosomes. So the four daughter cells would all contain extra or missing chromosomes. ● If the non-disjunction happens during meiosis II, one of the original Version 1
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daughter cells will divide normally producing two new daughter cells with the correct number of chromosomes. The cell that goes through non-disjunction will produce two daughter cells with abnormal chromosomes. So in this case two gametes would end up with a normal number of chromosomes and two would have extra or missing chromosomes. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Because the normal haploid cell has 19 chromosomes and the nondisjunction happens in meiosis II after meiosis I both daughter cells will have 19 chromosomes with chromatid pairs. After meiosis II one cell would go through normal separation of the sister chromatids producing two haploid cells with 19 chromosomes. In the second cell that goes through non-disjunction, 18 of the sister chromatids would separate normally while one sister chromatid pair would not separate. Thus one gamete would end up with one fewer chromosome for 18 total and the other would end up with an extra chromosome for 20 total. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to analyze the results of an experiment to predict how many chromosomes a cell would have when non-disjunction occurred. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that if nondisjunction occurs in meiosis II half of the gametes will have the normal number of chromosomes and half will have extra or missing chromosomes? Version 1
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51) D
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Clarify Question ● What is the key concept addressed by the question?● The question asks about the probabilities in independent assortment. ● What type of thinking is required?● You are being asked to apply your knowledge of independent assortment to calculate the probability of all chromosomes in a gamete coming from one parent. ● What key words does the question contain and what do they mean?● Probability that a gamete will receive only paternal chromosomes – by independent assortment, chromosomes align independently. The probability that four chromosomes all align together will be the product of each probability individually. Gather Content ● What do you know about independent assortment? How does it relate to the question?● For each chromosome pair lining up during metaphase I of meiosis there is a 50:50 (i.e. ½) probability for it to move into one new cell or the other. Consider Possibilities ● What other information is related to the question? Which information is most useful?● The probability of independent assortment is like flipping a coin. If the odds of a head is 50% or ½, then the probability of two heads is ½ x ½ = ¼. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● Following the coin tossing analogy, if a cell has 4 chromosomes that segregate independently the probability that the chromosomes from the father would all move to one cell is ½ x ½ x ½ x ½ = 1/16. Version 1
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to apply your understanding of independent assortment. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that the probability of two chromosomes segregating together is the probability of each separate event multiplied together? Did you think that the probabilities would be added? 52) B 53) A
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Clarify Question ● What is the key concept addressed by the question?● The question asks about separation of sister chromatids in meiosis. ● What type of thinking is required?● You are being asked to apply your knowledge of sister chromatids to predict what would happen if the separated in anaphase I of meiosis. ● What key words does the question contain and what do they mean?● Sister chromatid cohesin was released during anaphase I – this means that the sister chromatids would separate during meiosis. Gather Content ● What do you know about separation of sister chromatids? How does it relate to the question?● Normally sister chromatids remain attached during meiosis I and anaphase I. The sister chromatids then separate during anaphase II of meiosis II. Consider Possibilities ● What other information is related to the question? Which information is most useful?● If the kinetochore microtubules attach to opposite poles then the sister chromatids would move to opposite poles of the cell. ● If the chromatid cohesin that holds sister chromatids together was released during anaphase I then the sister chromatids would separate in anaphase I. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The cohesin being released in anaphase I and kinetochore microtubules attached to opposite poles of the cell would result in the sister chromatids migrating Version 1
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to opposite poles in anaphase I. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to apply your understanding of the separation of sister chromatids to predict what would happen if this occurred in anaphase I. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that once cohesin is released the sister chromatids separate? Did you realize that if the kinetochore microtubules attach to different poles of the cell, the sister chromatids will migrate to opposite poles? 54) 16
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Clarify Question ● What is the key concept addressed by the question?● The question asks about the amount of DNA in a cell at different stages of meiosis. ● What type of thinking is required?● You are being asked to analyze the amount of DNA present at different stages of meiosis. ● What keywords does the question contain and what do they mean?● 8 picograms of DNA in – after the S phase the cell will have 16 picograms of DNA. During prophase I the cell will not have segregated any chromosomes yet. Gather Content ● What do you know about meiosis? How does it relate to the question?● After a cell enters the S phase where the chromosomes replicate. The chromosomes then condense in prophase I but do not divide until the anaphase of meiosis. Consider Possibilities ● What other information is related to the question? Which information is most useful?● The chromosomes replicate but do not divide, so the cells will have twice the mass of DNA as in
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Choose Answer ● Given what you now know, what information and/or problem-solving approach is most likely to produce the correct answer?● Because the DNA has duplicated, but not divided again, the cells will have twice as much DNA. So, if they had 8 picograms to start with they will now have 16 picograms. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to calculate the amount of DNA in a cell at a specific stage in meiosis. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that after the cells will duplicate their DNA? Did you realize that the cells in prophase I will not have divided their DNA yet?
55) 20
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Clarify Question ● What is the key concept addressed by the question?● The question asks about the amount of DNA in a cell at different stages of meiosis. ● What type of thinking is required?● You are being asked to analyze the amount of DNA present at different stages of meiosis. ● What keywords does the question contain and what do they mean?● 40 picograms of DNA in – a cell in will have already gone through the S phase so it will not gain any more DNA. In moving to metaphase II the cell will have gone through one division. Gather Content ● What do you know about meiosis? How does it relate to the question?● After through meiosis I and the amount of DNA in each cell will be cut in half.
a cell will go
Consider Possibilities ● What other information is related to the question? Which information is most useful?● The chromosomes will have duplicated in the S phase and divided once in meiosis I but will not have divided a second time in metaphase II. Choose Answer ● Given what you now know, what information and/or problem-solving approach is most likely to produce the correct answer?● The DNA has already been duplicated in and will go through one division in meiosis. So, if a cell had 40 picograms of DNA in then after one division the cells will each have 20 picograms. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to calculate the amount of DNA in a cell at a specific stage in meiosis. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that after the cells had duplicated their DNA? Did you realize that the cells in metaphase II will have divided their DNA once?
56) 5
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Clarify Question ● What is the key concept addressed by the question?● The question asks about the amount of DNA in a cell at different stages of meiosis. ● What type of thinking is required?● You are being asked to analyze the amount of DNA present at different stages of meiosis. ● What keywords does the question contain and what do they mean?● 10 picograms of DNA in – after the S phase the cell will have 20 picograms of DNA. During meiosis the cell will go through two cell divisions, cutting the amount of DNA in half each time. Gather Content ● What do you know about meiosis? How does it relate to the question?● After , a cell enters the S phase and the chromosomes replicate. The chromosomes then divide twice through meiosis. Consider Possibilities ● What other information is related to the question? Which information is most useful?● The chromosomes replicate during the S phase and divide twice during meiosis, so the mass of DNA will be half as much as in . Choose Answer ● Given what you now know, what information and/or problem-solving approach is most likely to produce the correct answer?● Because the DNA has duplicated after the S phase the cell will have 20 picograms of DNA. After meiosis I the two daughter cells will have 10 picograms of DNA. After meiosis II the four gametes will have 5 picograms of DNA Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to calculate the amount of DNA in a cell at a specific stage in meiosis. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that after the cells will duplicate their DNA? Did you realize that at the end of meiosis two rounds of division would have occurred?
57) 28
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Clarify Question ● What is the key concept addressed by the question?● The question asks about tetrads ● What type of thinking is required?● You are being asked to apply your knowledge of tetrads to calculate how many will be present in a cell during metaphase I of meiosis. ● What key words does the question contain and what do they mean?● Tetrad in a cell with 2n = 56 – tetrads are paired homologues. Gather Content ● What do you know about tetrads? How does it relate to the question?● Tetrads form during metaphase I of meiosis when homologous chromosomes pair up. They are called tetrads because they contain four strands of DNA, two sister chromatids for each chromosome. Consider Possibilities ● What other information is related to the question? Which information is most useful?● If a cell is diploid, it has pairs of chromosomes equal to half the number of chromosomes in the diploid cell. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● If a cell has a 2n = 56 then it has 28 pairs of chromosomes. During metaphase I of meiosis these pairs form tetrads. Thus, if there are 28 pairs of chromosomes there will be 28 tetrads. Reflect on Process Version 1
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● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to apply your understanding of tetrads to calculate the number in a cell during metaphase I of meiosis. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that tetrads are formed from pairs of homologous chromosomes? Did you realize that if a diploid cell had 56 chromosomes that it would have 28 pairs? Did you think that a tetrad contained four chromosomes? 58) 4
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Clarify Question ● What is the key concept addressed by the question?● The question asks about the number of centromeres at different stages of the cell cycle. ● What type of thinking is required?● You are being asked to analyze an experiment to predict how many centromeres would be present. ● What key words does the question contain and what do they mean?● A cell in metaphase of mitosis has 8 centromeres – this means that the diploid number of chromosomes is 8. Gather Content ● What do you know about centromeres? How does it relate to the question?● Centromeres are at the center of a chromosome. They pair up during metaphase. So if a cell has 8 centromeres in its diploid state it has 8 chromosomes. Consider Possibilities ● What other information is related to the question? Which information is most useful?● In anaphase II the cells will now be haploid and contain half as many chromosomes. Each chromosome still contains one centromere. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● If the diploid number is 8, the haploid number will be 4 chromosomes, each with one centromere. Thus, the cell will have 4 centromeres. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to analyze the results of an experiment to calculate the number of centromeres on chromosomes in cells in anaphase II of meiosis. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that each chromosome contains a centromere? Did you realize that in anaphase II of meiosis the cells would be haploid? 59) 20
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Clarify Question ● What is the key concept addressed by the question?● The question asks about the number of chromatids in a cell during meiosis. ● What type of thinking is required?● You are being asked to analyze an experiment to predict the number of chromatids present in metaphase I of meiosis. ● What keywords does the question contain and what do they mean?● 10 centromeres are present in prometaphase. This means the cell has a diploid number of 10 chromosomes. Gather Content ● What do you know about the number of chromatids in a cell? How does it relate to the question?● Sister chromatids are formed after DNA replicates. Pairs of sister chromatids are chromosomes. Consider Possibilities ● What other information is related to the question? Which information is most useful?● In metaphase, I of meiosis, pairs of homologous chromosomes pair up, each with two sister chromatids. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● If a cell has 10 centromeres in prometaphase it has 10 chromosomes. The cell is still diploid, so 2n=10. In metaphase I of meiosis there will still be 10 chromosomes. Each chromosome contains two sister chromatids so there will be 20 chromatids in total. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to analyze the results of an experiment to calculate how many chromatids are present in metaphase I. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you understand that the cell would still be diploid in metaphase I? Did you realize that each chromosome would have a centromere? Did you understand that each chromosome would have two sister chromatids?
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Chapter 12 13e CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 1) Mendel demonstrated which of the following about inherited traits? Check all that apply. A) Traits can be hidden in some generations, but subsequently reappear unchanged in future generations. B) Traits segregate among the offspring of a cross. C) Certain traits are more likely to appear than their alternatives. D) Some traits show blending inheritance. E) Parents that both have the same trait can have offspring with an alternative trait.
2) Knight followed up on attempts of English farmers to improve varieties of agriculture with his studies on garden peas. When he crossed two true-breeding varieties, he found which of the following? Check all that apply. A) All the F1 offspring had the dominant trait. B) If both parents have the same trait, then all of their offspring will also have that trait. C) Some F2 offspring had the dominant trait and some had the recessive trait. D) Among the F2 offspring, more had the dominant trait and fewer had the recessive trait.
3) Mendel chose the garden pea for his work on inheritance for which of the following reasons? Check all that apply. A) Some traits in pea plants are controlled by one dominant allele and one recessive allele. B) Earlier investigators had shown segregation among the offspring. C) A large number of true breeding varieties were available. D) The generation time was short; many offspring can be grown easily. E) He could choose to self-pollinate or cross-pollinate.
4) Mendel's understanding of the inheritance of traits in peas, expressed in modern language, included: Check all that apply. Version 1
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A) parents transmit information encoded in genes. B) each individual contains two genes for each trait. C) not all genes are identical; alternative forms (alleles) exist. D) each of the alleles present in an individual is discrete. E) if a given allele is present, its effects will be seen in the individual.
5) Based on his monohybrid crosses, Mendel proposed which of the following? Check all that apply. A) Alternative forms of a trait are encoded by alternative alleles. B) The 2 alleles for a given trait separate when gametes form. C) Each allele has an equal probability of being passed on to the gametes. D) Allele pairs segregate independently of each other. E) Diploid individuals have 2 alleles for each trait.
6) Before Mendel's experiments with pea plants, which ideas formed the basis for most thinking about heredity? Check all that apply. A) Species gradually change over time B) The traits of both parents are blended together in their offspring C) Heredity occurs within species D) Some traits are dominant and some are recessive E) Traits are transmitted directly from parents to offspring
7) A scientist has an uncharacterized pea plant and wants to determine the plant’s genotype for seed color. In order to be certain to get conclusive results from a single cross, with what plant should it be crossed? Check all that apply. A) A green-seeded pea plant (yy) B) A yellow-seeded pea plant (YY) C) Itself
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8) A female with blood type O has a child with blood type O. She claims that a certain person is the child's father. Her claim would be proven false if this person has blood type: Check all that apply. A) O B) A C) B D) AB
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 9) The first detailed and quantitative studies on inheritance were carried out by an Austrian monk named_________blank. A) Mendel B) Darwin C) Mendeleev D) Benedict
10)
Mendel used the garden_________blank plant for his studies on inheritance. A) lily B) carrot C) onion D) pea
11) The phenotypic ratio for the F1 generation that results from a test cross between a homozygous recessive individual and a heterozygous individual is A) 1:1 B) 2:1 C) 3:1 D) 1:2:1
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12)
In modern terminology, Mendel's heredity "factors" are called A) DNA. B) chromosomes. C) genes. D) RNA.
13)
The observable expression of the genes present in an organism is called its A) phenotype. B) genotype. C) code. D) karyotype.
14)
Alternate forms of the same gene are called A) homologues. B) genotypes. C) cofactors. D) alleles.
15) The Principle of_________blank states that the 2 alleles present at each gene locus separate from one another during gamete formation and remain distinct. A) Alleles B) Segregation C) Crossing over D) Dominance E) Independent assortment
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16) Mendel used the_________blank to determine whether an individual with the dominant phenotype was homozygous or heterozygous for that trait. A) backcross B) testcross C) dihybrid cross D) F2 generation E) double cross
17) A diploid organism that has two identical alleles for a given trait is called_________blank for that trait. A) homozygous B) heterozygous C) dominant D) recessive E) codominant
18) An allele for a particular trait that is only expressed in the presence of a second copy of the same allele is called A) dominant. B) codominant. C) incompletelydominant. D) recessive. E) pleiotropic.
19) During his experiments with pea plants, Mendel referred to the trait that was expressed in the F1 or first filial generation as
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A) recessive. B) dominant. C) codominant. D) independent. E) homozygous.
20) In Mendel's experiments on seed color in pea plants, when a dominant yellow seedbearing plant was crossed with a recessive green seed-bearing plant, what was the approximate phenotypic ratio among the F2 generation? A) 1 yellow: 3 green B) 1 yellow: 1 green C) 3 yellow: 1 green D) all yellow E) 9:3:3:1
21)
Individuals that have 2 alleles for most gene loci are best described as A) haploid. B) diploid. C) dihybrid. D) homozygous. E) heterozygous.
22) If fertilization involves two gametes that contain different alleles of a given gene, the resulting offspring is A) dihybrid. B) haploid. C) heterozygous. D) homozygous. E) polygenic.
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23)
In a heterozygous individual, the allele being expressed is A) recessive. B) codominant. C) pleiotropic. D) dominant. E) epistatic.
24)
An allele that is present but unexpressed is A) codominant. B) dominant. C) pleiotropic. D) epistatic. E) recessive.
25)
The allelic make up of a cell or individual is referred to as its A) blueprint. B) genotype. C) phenotype. D) heritability.
26)
The observable outward manifestation of the genes of an individual is referred to as its A) blueprint. B) genotype. C) phenotype. D) genetic map.
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27) What type of cross is used to determine if an individual with the dominant form of a trait is homozygous or heterozygous? A) Double cross B) Dihybrid cross C) Reciprocal cross D) Test cross E) Back cross
28)
A cross where we follow the inheritance of two pairs of alleles is called A) homozygous. B) monohybrid. C) dihybrid. D) heterozygous. E) diallelic.
29) Let P = purple flowers and p = white, and T = tall plants and t = short. If the uppercase letters represent the dominant alleles, what is the phenotype of a plant with the genotype PpTt? A) purple flowers, tall B) purple flowers, short C) white flowers, tall D) white flowers, short E) pale purple flowers, intermediate height
30) Let P = purple flowers and p = white, and T = tall plants and t = short. What are the genotypes of the gametes that are produced by a plant that is heterozygous for both traits?
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A) PpTt only B) PT and pt C) P, p, T,and t D) PT, Pt, pT, andpt E) Tt, TT, tt, Pp,PP, and pp
31) Let P = purple flowers and p = white, and T = tall plants and t = short. Of the 16 possible gamete combinations in the dihybrid cross between two double heterozygotes, how many would produce the phenotypewhite, tall? A) None B) 1 C) 3 D) 9 E) 16
32)
Mendel's Principle of Independent Assortment states that different pairs of A) non-homologouschromosomes segregate independently of each other. B) sister chromatidssegregate independently of each other. C) non-sisterchromatids segregate independently of each other. D) alleles segregateindependently of each other. E) gametes segregateindependently of each other.
33)
The independent assortment of allele pairs is due to A) the independentsegregation of homologous chromosome pairs during anaphase II. B) the randomcombination of gametes during fertilization. C) the independentsegregation of sister chromatid pairs during anaphase I. D) the independentsegregation of non-sister chromatid pairs during anaphase II. E) the independentsegregation of homologous chromosome pairs during anaphase I.
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34)
If a single gene has 3 or more alternative forms, this is called A) pleiotropy. B) multiple alleles. C) epistasis. D) blendinginheritance. E) codominance.
35) Sometimes, one gene pair will interfere with the expression of a second gene pair in an interaction called A) incompletedominance. B) codominance. C) blendinginheritance. D) pleiotropy. E) epistasis.
36)
If an individual allele has more than one effect on the phenotype, this is called A) pleiotropy. B) epistasis. C) blendinginheritance. D) multiplealleles. E) polygenicinheritance.
37)
ABO blood group determination is an example of
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A) epistasis. B) incompletedominance. C) polygenicinheritance. D) multiple alleles. E) pleiotropy.
38) When Mendel crossed purple-flowered pea plants with white-flowered pea plants, he never got offspring with flowers that had an intermediate color. This was counter to the theory of A) independentassortment. B) blendinginheritance. C) directtransmission of traits. D) segregation ofalleles. E) continuousvariation of traits.
39) Sometimes, when Mendel crossed two pea plants with each other, he obtained a phenotypic ratio of 3:1 purple-flowered pea plants to white-flowered pea plants. These results are consistent with which set of parents? A) Homozygous purple pea plant and homozygous white pea plant B) Heterozygous purple pea plant and homozygous white pea plant C) Heterozygous purple pea plant and homozygous purple pea plant D) Heterozygous purple pea plant and heterozygous purple pea plant
40) Height is a trait that shows continuous variation in humans. In pea plants, on the other hand, the tall allele is dominant over the short allele and there are no intermediate heights. What is the best explanation for this difference?
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A) The alleles thatcontrol height in pea plants are epistatic. B) The alleles thatcontrol height in pea plants are pleiotropic. C) The alleles thatcontrol height in humans are pleiotropic. D) Height is apolygenic trait in humans. E) Height is apolygenic trait in pea plants.
41) An extensive study was conducted on identical twins who were separated at birth. Among other things, the study showed that the individual from each pair who received better nutrition during childhood tended to score higher on standardized intelligence tests. This can best be described as an example of how A) mutation alters phenotype. B) environment altersphenotype. C) environment altersgenotype. D) mutation altersgenotype. E) pleiotropic genesaffect more than one trait.
42) Prisha knows her blood type is A, but Sebastian does not know his blood type. However, Sebastian knows that his mother and father both had blood type B. Prisha and Sebastian's first child is a boy with type O blood. Based on this information, Sebastian's blood type could be A) B only. B) either B or O. C) O only. D) either AB or O. E) A only.
43) A person who has lost a large amount of blood but is still alive is found in a wrecked automobile under a highway bridge. Several people are helping the paramedics load the victim into the ambulance. After the ambulance has departed for the hospital, you overhear the following conversation from the persons who helped the paramedics. "I am certain that when that guy gets to the hospital, they will transfuse him with any blood that they have in the blood bank since he has lost so much blood." The other person says, "Yeah, I bet you're right!" Having had a biology course, you know which blood could be safely given to anyone. Select it below.
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A) A B) B C) AB D) O
44)
A diploid individual carrying two identical alleles at a given gene locus is called A) homologous. B) heterozygous. C) homozygous. D) dihybrid.
45)
The ______ of an organism refers to the alleles that are present. A) genotype B) karyotype C) epistasis D) phenotype E) pleiotropy
46)
The observable expression of the genes present is called A) genotype. B) karyotype. C) epistasis. D) phenotype.
47)
A diploid individual carrying two different alleles at a given gene locus is called
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A) homologous. B) heterozygous. C) homozygous. D) polygenic.
48) A male fruit fly has the genotype PpYYrrTt. In terms of these 4 allele pairs, how many different types of gametes can he form? A) 2 B) 4 C) 8 D) 16
49) In white tigers, the absence of fur pigmentation is caused by a recessive allele that also causes the tigers to be cross-eyed. If two tigers heterozygous for this allele mate, what do you expect to see among the offspring? A) 1/4 will be both white and cross-eyed, 3/4 will be orange with normal eyes. B) 1/4 will be white with normal eyes, 1/4 will be white and cross-eyed, 1/4 will be orange with normal eyes, and 1/4 will be orange and cross-eyed. C) 1/16 will be white and cross-eyed, 15/16 will be orange with normal eyes. D) 1/3 will be both white and cross-eyed, 2/3 will be orange with normal eyes. E) 1/4 will be orange with normal eyes, 3/4 will be both white and cross-eyed.
50) Let Y = yellow and y = green, and R = round and r = wrinkled. You cross YYRR peas with yyrr peas. All of the F1 individuals are yellow and round with a genotype of YyRr. You then perform an F2 cross and get the expected 9:3:3:1 phenotypic ratio. What proportion of the F2 plants are expected to be heterozygous for both traits? A) 1/16 B) 1/4 C) 1/2 D) 9/16
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51) Let R = red pigment and r = no pigment. In carnations, RR offspring make a lot of red pigment, rr offspring make no pigment and Rr offspring make a small amount of red pigment, thus appearing pink. Pink carnations are therefore an example of A) codominance. B) incomplete dominance. C) epistasis. D) pleiotropy.
52)
A Punnett square is generally used to A) determine thegenotype of each parent from its phenotype. B) determine thephenotype of each parent from its genotype. C) predict thegenotypic ratio among the offspring. D) predict the numberof offspring that will exhibit each genotype.
53) Achondroplasia is caused by an autosomal dominant mutation in the fibroblast growth factor receptor 3 (FGFR3) gene. A person who carries this mutation has shorter limbs than average. Two copies of the mutant gene are invariably fatal before or shortly after birth. If a person with achondroplasia has children a person of average height, what is the probability that both their first child and second child will have achondroplasia? A) 1/8 B) 1/4 C) 1/2 D) 1
54) Mendel performed reciprocal crosses in which he used pollen from a white-flowered plant to fertilize a purple-flowered plant and pollen from a purple-flowered plant to fertilize a white-flowered plant. What did these reciprocal crosses demonstrate?
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A) The female gametemade a larger genetic contribution to the offspring than the malegamete. B) Each parent madean equal genetic contribution to the offspring. C) Flower color is asex-linked trait. D) The traits of flower color and sex assort independently. E) The male gamete made alarger genetic contribution to the offspring than the female gamete.
55) You toss a coin twice. Because the outcome of the first toss does not affect the outcome of the second toss, these 2 events are called A) mutually exclusive. B) independent. C) dependent. D) random.
56) If you are tossing a six-sided die, what is the probability of getting either a 1 or a 2 on your first toss AND a 1 or a 2 on your second toss? A) 1/18 B) 1/9 C) 1/6 D) 1/3 E) 2/3
57) In humans, the sickle-cell trait is caused by a single mutant allele, but sickle-cell disease only occurs in individuals that are homozygous for the sickle-cell allele. A male and female each carry the trait, but do not have sickle-cell disease. What is the probability that their first two children will both have sickle-cell disease?
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A) 1/16 B) 1/8 C) 1/4 D) 3/8 E) 1/2
58) In rabbits, there is a gene that controls ear length, with a dominant allele "T" for long ears and a recessive allele "t" for short ears. At another gene locus, there are alleles “B” for black coat and “W” for white coat. Neither the B or W allele is dominant, and BW produces a gray coat. These two allele pairs assort independently. If a gray rabbit that is heterozygous at the gene locus controlling ear length is mated with a white rabbit that is also heterozygous at the gene locus controlling ear length, what is the probability that their first offspring will be gray with long ears? A) 1/16 B) 3/16 C) 1/8 D) 3/8 E) 1/2
59) In rabbits, there is a gene that controls ear length, with a dominant allele "T" for long ears and a recessive allele "t" for short ears. At another gene locus, there are alleles “B” for black coat and “W” for white coat. Neither the B or W allele is dominant, and BW produces a gray coat. These two allele pairs assort independently. If a gray rabbit that is heterozygous at the gene locus controlling ear length is mated with a white rabbit that is also heterozygous at the gene locus controlling ear length, what proportion of the long-eared offspring will be homozygous for the long-eared trait? A) 1/8 B) 1/4 C) 1/3 D) 1/2
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Parent Blood Types
A and B
A and A
B and O
Child Blood Type
O
B
AB
Three babies were recently mixed up in a hospital. Based on the data in the table above, the couple with blood types A and B are the actual parents of the child with blood type A) O B) B C) AB D) None of these babies could be the child of the couple with blood types A and B.
61) Different phenotypes produced for the same genotype due to environmental variation is called _____. A) heritability B) quantitative inheritance C) phenotypic plasticity D) pleiotropy
SECTION BREAK. Answer all the part questions. 62) A secretor (allele seS) is a person who secretes their blood type antigens into body fluids such as saliva. By comparison, a non secretor (allele seNS) does not. A person's status as a secretor or non secretor is independent of blood type. Consider the following inheritance pattern of this trait: Secretor (seS/seS) x Secretor (seS/seS) → NS
NS
All offspring are secretors NS
NS
Nonsecretor (se /se ) x Nonsecretor (se /se ) → S
S
NS
NS
All offspring are nonsecretors
Secretor (se /se ) x Nonsecretor (se /se ) →
All offspring are secretors
Heterozygote secretor (seS/seNS) x Heterozygote secretor (seS/seNS)
75% secretors, 25% nonsecretors
62.1)
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A) incompletely dominant. B) recessive. C) dominant. D) codominant.
62.2)
The genotypic ratio produced in the last cross is most likely
A) 3:1 B) 1:2:1 C) 2:1 D) 9:3:3:1 E) 1:1
63) Let Cy = curly wings and Cy+ = wild type. In Drosophila, the Cy allele behaves as a dominant mutation that produces curly wings in the heterozygous condition (Cy/Cy+), but also behaves as a recessive lethal mutation. Flies homozygous for the Cy allele die before reaching adulthood.
63.1) If you crossed flies heterozygous for the Cy allele, which phenotype(s) would you find in the adult F1 generation? A) Both wild type and curly wings B) Wild type only C) Curly wings only D) None because all the F1 flies would die before reaching adulthood.
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Answer Key Test name: Chap 12_13e_Raven 1) [A, B, C, E] 2) [A, C, D] 3) [B, C, D, E] 4) [A, B, C, D] 5) [A, B, C, E] 6) [B, C, E] 7) [A, C]
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Clarify Question ● What is the key concept addressed by the question?● This question asks you to consider the results of various crosses, and indicate which would serve as a testcross to determine the parental genotype. ● What type of thinking is required?● You must Analyze the information to determine which plant(s) would work. ● What keywords does the question contain?● The scientist wants to determine the plant’s genotype – the alleles it carries. Is it YY, Yy, or yy? Gather Content ● What do you already know about test crosses?● We learned about Mendel’s use of the testcross. He used homozygous recessive plants to cross to the uncharacterized plant. Because they carry two recessive alleles, only the traits from the tested individual contribute to the phenotype. ● But is this the only possibility for this example? Consider Possibilities ● What other information is related to the question? Which information is most useful?● What strategy can you use to determine which cross(es) will provide the needed information? ● What about considering the results of each possibility in turn? Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● With a pen and paper, diagram each of the three possible answer choices. ● First, consider that the uncharacterized plant may be YY, Yy, or yy. Our goal is to distinguish between these possibilities. Which crosses will Version 1
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differentiate them? ● If you cross the unknown plant to a green-seeded plant (yy), what will result? If the unknown plant is YY, then YY x yy → 100% Yy yellow seeds. If it is Yy, then Yy x yy → 50% Yy yellow seeds, 50% yy green seeds. If it is yy, then yy x yy →100% yy green seeds. The three possibilities distinguish the genotype. This is the traditional testcross. ● If you cross the unknown plant to a yellow-seeded plant (YY), what will result? If the unknown plant is YY, then YY x YY → 100% YY yellow seeds. If it is Yy, then Yy x YY → 50% YY yellow seeds, 50% Yy yellow seeds. If it is yy, then yy x YY →100% Yy yellow seeds. Although the genotypes vary, the phenotypes are ALL yellow seeds. This cross provides no information at all. ● What about selfing the mystery plant? If the unknown plant is YY, then YY x YY → 100% YY yellow seeds. If it is Yy, then Yy x Yy → 25% YY yellow seeds, 50% Yy yellow seeds, and 25% yy green seeds. If it is yy, then yy x yy →100% yy green seeds. Three different phenotype ratios distinguish the possibilities. This also works! Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. ● So although self-fertilization is not the traditional testcross, it does also work to determine the plant’s genotype. However, the recessive testcross is a more foolproof method – can you imagine why? ● To answer this question, did you try using pen and paper to write out the crosses? With three possible mystery plant genotypes and three possible tester plants, that’s 9 different crosses to consider. So you can see that writing it out will help! Version 1
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8) [D]
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Clarify Question ● What is the key concept addressed by the question?● This question addresses a single gene cross with recessive and co-dominant alleles for blood type. ● What type of thinking is required?● You need to Analyze the information given to determine which blood type(s) are incompatible with being the father. ● What key words does the question contain?● Blood type O, A, B, and AB are phenotypes. They are determined by the alleles IA, IB, and i. Gather Content ● What do you already know about single gene crosses and recessive and co-dominant alleles?● This question asks which paternal genotypes are incompatible with a child of blood type O, when the female’s blood type is also O. ● You know that blood type O is determined by the genotype i i – that is, two recessive alleles. ● So both the female’s genotype and the child’s must be i i. ● What are the genotypes for each possible blood type? Blood type A may be IA IA or IA i. Blood type B may be IB IB or IB i. Blood type O must be i i. Blood type AB must be IA IB. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Test out each possible cross in turn. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Since the child has two recessive alleles, we know that the father must have contributed Version 1
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a recessive allele. ● Does that mean the father must be blood type O? (no) ● If the father is blood type A, he could be IA i and contributed the i allele. ● If the father is blood type B, he could be IB i and contributed the i allele. ● If the father is blood type O, he is i i and contributed an i allele. ● BUT, if the father is blood type AB, he can only be IA IB. There is no i allele to contribute. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you remember that IA and IB are codominant alleles, but that the i allele is recessive? ● Did you write out the crosses or use a Punnett square to help answer the question? ● Did you realize that blood type A could be determined by a heterozygous IA i genotype? ● Something to think about: is the female’s blood type important for answering the question? Would the answer change if she was blood type B? 9) A 10) D 11) A 12) C 13) A Version 1
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14) D 15) B 16) B 17) A 18) D 19) B 20) C 21) B 22) C 23) D 24) E 25) B 26) C 27) D 28) C 29) A 30) D
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Clarify Question ● What is the key concept addressed by the question?● This question requires two steps. First, you must determine the genotype of a plant that is heterozygous for the two genes—then you can decide what gametes that plant will produce. ● What type of thinking is required?● You need to use your understanding of heterozygosity and independent assortment, and Apply it to a plant with this particular set of genes. ● What key words does the question contain?● The plant is heterozygous for both traits – it carries two alleles for each gene. The question asks which gametes, or germ cells, are produced. Gather Content ● What do you already know about how gametes are produced? How does it relate to the question?● A diploid organism has two copies of each gene. In this case, it is heterozygous for both genes – it has two different alleles for each. So the plant is Pp Tt. ● Gametes are haploid and carry only one allele for each gene. They assort independently (unless you have reason to believe that they are linked on a chromosome). So any gamete may receive P or p, and any gamete may receive T or t. ● This creates four possible combinations: PT, Pt, pT, and pt. Consider Possibilities ● What other information is related to the question? Which information is most useful?● The gametes must be haploid and carry only one copy of each gene. So you can eliminate answers that have “Pp”, etc. ● A gamete must also contain a copy of every gene. So each gamete Version 1
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must have P or p, plus a T or t. ● Finally, you know that genes assort independently. So there are four types of possible gametes, not just PT and pt. Choose Answer ● Given what you now know, what approach is most likely to produce the correct answer?● Determine the genotype of the double heterozygous plant. Then determine every possible combination of the four alleles to describe the gametes. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Apply your knowledge and understanding to this unfamiliar situation. ● You will benefit from reading slowly and carefully. This question required determining the plant genotype before figuring out the gametes produced. 31) C
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Clarify Question ● What is the key concept addressed by the question?● This question requires you to work out the results of a dihybrid cross, using the Punnett square approach. Jotting on scrap paper will help. ● What type of thinking is required?● You must Analyze to determine the 16 gamete combinations produced by the cross, and then count how many of them have a white, tall phenotype. ● What key words does the question contain?● A dihybrid cross is a cross between two dihybrids, or double heterozygotes – organisms that are heterozygous for two different genes. So a dihybrid cross is Aa Bb x Aa Bb. Or in this case, Pp Tt x Pp Tt. Gather Content ● What do you already know about dihybrid crosses? How does it relate to the question?● You may remember that Punnett squares are a good way to work out the results of a dihybrid cross. A pen and paper will help. Consider Possibilities ● What other information is related to the question? Which information is most useful?● You may decide there are only two genotypes that produce white, tall plants – TT pp and Tt pp. This is correct. But careful reading of the question shows that it asks for the proportion of the 16 gamete combinations. These 16 combinations are the results of drawing the Punnett square, which differentiates between the T (maternal) t (paternal) pp combination and the t (maternal) T (paternal) pp combination. Choose Answer ● Given what you now know, what information and/or problem solving Version 1
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approach is most likely to produce the correct answer?● You could do this in your head, but drawing a Punnett square on scrap paper is an easier approach. Write the possible parental gametes along both the top and side: PT, Pt, pT, and pp. Fill in the 16 combinations, then circle the ones that have a white, tall phenotype. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. ● Some questions may be deceptively short, but require some time to work out the correct answer. Don’t be shy about using pen and paper to help you by diagramming the cross– working geneticists do it all the time! 32) D 33) E 34) B 35) E 36) A 37) D 38) B 39) D
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Clarify Question ● What is the key concept addressed by the question?● Instead of asking you to derive the phenotype ratio from the cross, here the question asks you to determine which genotypes could be crossed to produce a certain phenotypic ratio. ● What type of thinking is required?● You have to use your understanding of monohybrid crosses and Apply it to this scenario of a 3:1 ratio of purple: white flowers. ● What keywords does the question contain?● The phenotypic ratio is the ratio of phenotypes – the physical traits. Remember that a certain phenotype, like purple flowers, may result from more than one genotype. Gather Content ● What do you already know about crosses and phenotype ratios? How does it relate to the question?● Punnett squares are very helpful for determining phenotype ratios. A pen and paper might be helpful. ● Don’t forget that the purple flower color (P) is dominant over white (p). Consider Possibilities ● What other information is related to the question? Which information is most useful?● If you don’t know the answer right away, look at the answer choices. Could you determine the phenotypic ratios that would result from each choice, to find the one that matches 3:1 purple: white? Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Look at the answer choices. For each, you will need to translate the words Version 1
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(“homozygous purple”) into the genotype (“PP”). What phenotypes result from each of these crosses? ● Recall that P is dominant for the purple phenotype. So a cross of homozygous purple (PP) x homozygous white (pp) will produce only Pp purple offspring. ● Recall that gametes receive one allele randomly in equal amounts. So a cross of heterozygous purple (Pp) x homozygous white (pp) will produce half purple (Pp) offspring and half white (pp) offspring. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Apply your knowledge and understanding to this unfamiliar situation. You may have decided that a cross between Pp x Pp produces just three types of offspring: PP, Pp, and pp. Using a Punnett square can help you identify that there are two categories of Pp offspring: P (maternal) p (paternal) and p (maternal) P (paternal). So three of the four combinations are purple, producing a 3:1 ratio. ● Even if you didn’t remember that monohybrid crosses produce a 3:1 ratio, you could solve the problem by considering each of the answer choices. 40) D 41) B
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Clarify Question ● What is the key concept addressed by the question?● This question focuses on the difference between genotype and phenotype. ● What type of thinking is required?● You must Apply your understanding of genotype and phenotype to this situation where identical twins experience different nutrition. ● What key words does the question contain?● It is important to distinguish genotype and phenotype, and mutation and environment. Genotype is the set of genes in an individual. The genotype does not change, unless it experiences a mutation. Phenotype is the description of the individual’s traits – even behavioral traits, like intelligence. The phenotype is determined not just by genes, but also by environmental influences – anything from outside the body. ● An answer choice mentions pleiotropic genes – these are genes that act on different traits. For instance, a gene for collagen may affect the function of skin, tendons, and bones. Or a mutation in a gene that controls transcription may have dramatically different results in different cell types, depending on what genes it controls. Gather Content ● What do you already know about genotype and phenotype? How does it relate to the question?● We know that identical twins share the same genes – the same genotype. Genotype doesn’t change during the lifetime of the individual. ● Intelligence is a trait – an aspect of the phenotype. We can imagine that better nutrition allowed a healthier brain to grow in the lucky twin. ● Nutrition is a type of environmental influence. Consider Possibilities Version 1
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● What other information is related to the question? Which information is most useful?● You might consider that the twin with poor nutrition may have experienced a mutation. That is possible – good nutrition can help prevent mutation-based diseases like cancer. Nutrients like antioxidant help cells to neutralize mutation-causing chemicals. ● However, a mutation is not the likely basis for the lower intelligence score in the unlucky twin, because mutations happen in individual cells. When they cause cancer, the mutated cell may grow and produce a tumor, yet the rest of the brain is unaffected. ● The most likely explanation is that better nutrition improved the health of the entire brain. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Since intelligence is part of the phenotype, and nutrition is part of the environment, we can conclude that this example shows how environment can alter the phenotype. ● Does this mean that genotype does not affect intelligence? ● Can you think of other examples in which genotype and environment work together to affect phenotype? Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Apply your knowledge and understanding to this unfamiliar situation. ● When a question like this trips you up, consider whether the scientific terms were too unfamiliar. Jotting down key terms as you read the chapter, or making flash cards may help you remember them. Version 1
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● As you learn about genetics, remember that nature is more complicated than Mendel’s early experiments would indicate. Genes are not the only influence on an individual’s phenotype – the environment is important too. Consider the effects of nutrition, infection, and even social interactions. Sometimes people call this the “nature/nurture” dichotomy. In real life, most traits are a combination of nature and nurture. In other words, an individual’s phenotype is influenced by both its genotype and its environment. 42) B
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Clarify Question ● What is the key concept addressed by the question?● This question deals with blood type alleles, which have multiple alleles and have a codominance relationship. ● What type of thinking is required?● This question asks you to Analyze the scenario, and use logic to deduce William’s genotype. ● What key words does the question contain?● Three blood types are mentioned: A, B, and O. It is important to remember that O is a recessive allele – it does not add sugars to the cell surface. Gather Content ● What do you already know about blood type alleles? How does it relate to the question?● Blood type is controlled by multiple alleles. The phenotypes A, B, and O are encoded by the alleles IA, IB, and i. ● The i allele is recessive to IA and IB. So a person with type A blood could have a genotype of either IA IA or IA i. Someone with type O must have the genotype ii. ● The A and B alleles are codominant, so IA IB gives the blood type AB. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Sebastian says both his parents were type B. They may each have been either IB IB or IB i. Based on this, Sebastian may be either IB IB, IB i, or ii. ● He could not have received the IA allele. So which answer choices can we rule out? Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● We can Version 1
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narrow down the possibilities for Sebastian’s genotype based on what we learned about his parents and his child. ● Based on his two type B parents, what are possible genotypes for Sebastian? (IB IB, IB i, or ii) ● What are the possible genotypes for Sebastian’s type O child? (only ii) ● What allele must Sebatian have contributed to his child? (i) So what genotype can be ruled out for Sebastian? (We can rule out IB IB as a possibility) ● The two possibilities we have left cannot be ruled out -- IB i, or ii. Which blood type do these correspond to? (Type B or Type O) Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you get confused by the information about Irene? Is her blood type an important piece of information? ● A pen and paper may help keep track of the information in questions like these. In your diagram, show three generations: Sebastian’s parents, Sebastian and Prisha, and their child. Note both phenotype and possible genotypes for each person. 43) D 44) C 45) A 46) D 47) B 48) B
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Clarify Question ● What is the key concept addressed by the question?● This question asks about allele combinations in gametes. ● What type of thinking is required?● The question requires you to Apply your understanding of alleles and gametes to four particular genes in a fly. ● What key words does the question contain?● A genotype is a set of genes, and gametes are the haploid germ cells (i.e., sperm in this case). Pp represents two alleles of the P gene – P and p. YY represents two alleles of the Y gene, etc. Gather Content ● What do you already know about alleles and gametes? How does it relate to the question?● Gametes get one copy of each gene. Thus they get one of the alleles, randomly assorted. ● So a gamete can get P or p for the P gene. Only Y is available for the Y gene (both alleles are the same). Only r is available for the R gene. T or t is possible for the T gene. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Does the choice of one allele affect the choice of the others? No. Generally speaking, genes assort independently. If genes are close together on the chromosome, they maybe linked, but this question does not indicate linkage. So the P allele can pair with either the T or t allele. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Now it is a Version 1
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simple matter of counting the possible combinations. Pen and paper may be handy for this. ● The P allele can assort with what other alleles? (Only Y, only r, and either T or t. That makes two possibilities: P Y r T and P Y r t) ● The p allele can assort with what other alleles? (Only Y, only r, and either T or t. That makes two possibilities: p Y r T and p Y r t) ● Add them up and you get how many total possible allele combinations? (4) Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Apply your knowledge and understanding to this unfamiliar situation. ● Did you recall that each gamete receives one allele of each gene? ● Did you recall that genes assort independently? ● Did you use pen and paper to help figure the combinations? 49) A
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Clarify Question ● What is the key concept addressed by the question?● This question asks about the phenotypic ratio that results from a cross of two heterozygotes. This is similar to the monohybrid cross we studied in the example of Mendel’s purple and white pea flowers. ● What type of thinking is required?● You need to Analyze the information to determine the phenotype ratio. ● What key words does the question contain?● A recessive allele is one that is only exhibited in the phenotype of a homozygote. The parents in this cross are heterozygous – they carry two different alleles. Gather Content ● What do you already know about monohybrid crosses?● Recall that we saw a monohybrid cross like this for purple and white flower color in peas. Consider Possibilities ● What other information is related to the question?● Punnett squares are a useful way to determine both genotype and phenotype ratios. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● You could do this in your head, but drawing a Punnett square on scrap paper is an easier approach. Write the possible parental gametes along both the top and side. Just make up your own abbreviation – say, W (orange) and w (white). Fill in the 4 combinations. ● You should get WW, Ww, wW and ww. Which are the phenotypes of each? ● Remember, the w allele is recessive for both white fur and crossedVersion 1
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eyes. So only ww are white and cross-eyed. The other three categories are orange with normal eyes. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. ● For questions like this, try drawing a Punnett square. ● Remember that even though there are three genotypes – WW, Ww, and ww – they are not in equal proportions. There are two categories of Ww offspring, giving a 1:2:1 genotype ratio, and a 3:1 phenotype ratio. So only 1/4 of offspring are the white, cross-eyed ww tigers. 50) B
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Clarify Question ● What is the key concept addressed by the question?● You may recognize that this is a dihybrid cross, like the example in the text. ● What type of thinking is required?● You need to Analyze the information to determine the genotype ratios. ● What key words does the question contain?● The genotype refers to the alleles present, while the phenotype is the visible trait, like “round” or “wrinkled”. F1 and F2 are the generations of crosses. The plants we are looking for are heterozygous for both traits. In other words, they have two different alleles for each trait, or Yy and Rr. Gather Content ● What do you already know about dihybrid crosses?● Dihybrid crosses produce numerous categories of offspring. It can be hard to keep track of them all without a method of diagramming the cross. What method is helpful for keeping track of genotypes and phenotypes from a cross? Consider Possibilities ● What other information is related to the question? Which information is most useful?● Punnett squares are a useful way to determine both genotype and phenotype ratios. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Try drawing a Punnett square. Write the possible gametes on the top and the side. ● The different gametes for a YyRr parent are: YR, Yr, yR, and yr. ● There are 16 combinations of offspring . ● Which offspring are heterozygous for both traits, or YyRr? (Four of Version 1
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the sixteen categories have this genotype, or 1/4.) Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. ● Writing down the cross is helpful with questions like these. Even better, draw the Punnett square. 51) B 52) C 53) B
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Clarify Question ● What is the key concept addressed by the question?● This question requires two steps: figuring out the likelihood of an affected offspring, then calculating the probability of the first and second children both being affected. You can calculate the expected phenotype ratio from the crosses to determine the probability of the achondroplasia phenotype. ● What type of thinking is required?● You need to Analyze the information to determine the probability of the two children being affected. ● What key words does the question contain?● Achondroplasia may be unfamiliar to you, but just treat it like any autosomal dominant mutation – that is, an allele on a non-sex chromosome, with the trait exhibited in the heterozygote. Gather Content ● What do you already know about phenotype ratios from crosses?● What is the genotype of the parent with average height? ● What is the genotype of the parent with achondroplasia? (Hint: Remember that the question mentioned that two copies of the mutant gene are fatal.) ● Treat each child as a cross. The expected phenotype ratio will tell you the likelihood that the child will have the achondroplasia phenotype. What method have you learn for keeping track of genotypes and phenotypes from a cross? Consider Possibilities ● What other information is related to the question? Which information is most useful?● Punnett squares are a useful way to determine both genotype and phenotype ratios. Version 1
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Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Try drawing a Punnett square. Write the possible gametes on the top and the side. ● The only gametes for the average height parent are FGFR3+. ● The gametes for the parent with achondroplasia are FGFR3+ and FGFR3-. ● There are 2 combinations of offspring : FGFR3+/ FGFR3- and FGFR3+ / FGFR3+, in equal ratio. So there is a 50% chance that a child will have achondroplasia. ● If the first child has achondroplasia (50%), there is again a 50% chance that the second child will have achondroplasia. The second child is unaffected by the result for the first child. So the total probability that both child 1 and 2 will carry the achondroplasia phenotype is 1/2 x 1/2, or 1/4. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you see the connection between phenotype ratios and probability for one child? Now you may appreciate another aspect of how Punnett squares can be useful. ● Remember, in genetics treat each child as an independent event – like a coin flip. 54) B 55) B 56) B Version 1
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Clarify Question ● What is the key concept addressed by the question?● This question targets your understanding of probability. ● What type of thinking is required?● You need to Apply your understanding of probability to this particular example of rolling a die. ● What key words does the question contain?● A die is the singular form of the word dice. Probability is the likelihood of an event, expressed as a fraction or a percentage. Gather Content ● What do you already know about probability?● We have learned about probability in the context of genetics. Like rolling a die, in genetics the outcome from one reproductive event does not affect the likelihood of a subsequent event. Consider Possibilities ● What other information is related to the question? Which information is most useful?● For this problem, break it into two events: the likelihood from the first roll and the second. ● Then multiply the two probabilities to get the overall probability. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● What is the likelihood of rolling a 1 or 2 on the first roll? Those are 2 out of 6 possibilities, so 2/6 or 1/3. ● The second roll has the same probability – it is unaffected by the first result. So 1/3 for the second roll. ● The probability of the combined scenario is found by multiplying the two individual probabilities. 1/3 x 1/3 = 1/9. Version 1
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Apply your knowledge and understanding to this unfamiliar situation. ● Make sure to read questions carefully. Would the result be the same if you were asked about rolling a 1 or 2 on the first roll, and then rolling the SAME number on the second roll? ● With dice and with genetics, remember that independent events do not affect each other. Even if a couple has 4 sons in a row, their fifth baby still has a 50% chance of being a boy! 57) A The parents must both be heterozygous (Aa x Aa). Therefore, the probability that their next child will have sickle-cell disease is 1/4. The probability that their next child will be a boy is 1/2. Since these are independent events, the probability that their next child will have sicklecell and be a boy is 1/4 x 1/2 = 1/8.
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Clarify Question ● What is the key concept addressed by the question?● This question asks about a monohybrid cross and combines that with a probability problem. ● What type of thinking is required?● You need to Analyze the information to determine the probability of both the two children having sickle cell disease. ● What keywords does the question contain?● The sickle-cell trait is the phenotype of heterozygous carriers of the allele (HbA / HbS). They have slightly altered blood cells but usually no apparent health effects. Sickle-cell disease is the phenotype of people homozygous for the mutant allele (HbS / HbS) – they have anemia due to poor circulation and oxygen transport. Gather Content ● What do you already know about monohybrid crosses? About determining the probability of two independent events?● Since the parents carry the trait but do not have the disease, they must be heterozygous (HbA / HbS). The question asks for the probability that the first two children will both have the disease (both be HbS / HbS). Consider Possibilities ● What other information is related to the question? Which information is most useful?● Did you recognize that this cross is a monohybrid cross, much like the example with Mendel’s purple pea flowers? Do you remember the classic phenotype ratio? ● Punnett squares are also a useful way to determine both genotype and phenotype ratios. Choose Answer Version 1
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● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Try drawing a Punnett square. Write the possible gametes on the top and the side. ● The gametes for each parent are HbA and HbS. There are four categories of offspring: HbA / HbA, HbA / HbS, HbS / HbA, and HbS / HbS. ● Only the last category will have sickle cell disease: HbS / HbS. So there is a ¼ probability for each child. ● Since each child is an independent event, we must multiply the two probabilities to get the overall probability. ¼ x ¼ = 1/16 Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you try writing out the genotypes and the cross? Did you draw a Punnett square? ● Did you remember to treat each child as an independent event? The outcome of the first child does not affect subsequent children. ● Did you read carefully? Would the answer have been different if the question said “What is the probability that either of their first two children will have the sickle-cell disease?” 58) D
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Clarify Question ● What is the key concept addressed by the question?● This question asks about a cross involving the independent assortment of two genes. This is similar to Mendel’s dihybrid cross, although in this case one parent is homozygous for one of the genes. Also, one gene has dominant and recessive alleles, but the other gene has an incompletely dominant allele: when heterozygous, the “black” allele (B) only turns the fur gray. ● What type of thinking is required?● This question requires you to Analyze the information to determine the phenotype ratio of the offspring. ● What key words does the question contain?● Pay close attention to the description of the alleles. The dominant allele will exhibit its phenotype in the hybrid, but the recessive allele will exhibit its phenotype only when homozygous. The alleles of the fur color gene are incompletely dominant. In the heterozygote, fur is gray – an intermediate phenotype. The two genes assort independently – this tells you that they are either on separate chromosomes or far apart on a chromosome, and the alleles end up in the gametes randomly. If a gamete gets a T allele, it could also get either a B or a W from the other gene. ● Don’t be confused by the gene abbreviations. The abbreviation for the ear length gene is T or t. For the fur gene, however, the abbreviations are different letters: B or W. From the question, though, we know that these are alleles of the same gene. So there are two genes in this scenario: the ear length gene T/t, and the fur color gene B/W. Gather Content ● What do you already know about two-gene crosses and independent assortment?● Recall the dihybrid cross from the text. A two-gene cross Version 1
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can produce as many as 16 categories of offspring. This is not a problem to do in your head! Consider Possibilities ● What other information is related to the question? Which information is most useful?● Punnett squares are a useful way to determine both genotype and phenotype ratios. ● What is the genotype of the gray rabbit heterozygous for ear length? (BW Tt) ● What is the genotype of the white rabbit heterozygous for ear length? (WW Tt) ● What is the genotype of the offspring in question, gray with long ears? (BW TT or BW Tt) Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Try drawing a Punnett square. Write the possible gametes on the top and the side. ● The gametes for the gray heterozygous (BW Tt) rabbit are B T, B t, W T, and W t. Gametes for the white heterozygous (WW Tt) rabbit are W T and W t. ● This creates 8 categories of offspring. Of these 8 categories, 3 are gray with long ears: BW TT, BW Tt, and BW tT. So the phenotype ratio is 3/8, and the likelihood that any individual rabbit will be gray with long ears is 3/8. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Analyze the information given, using logic, to Version 1
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dissect the problem and determine the answer. ● Did you use a pen and paper to help with this question? ● Did you diagram the categories of offspring with a Punnett square? ● Did you recognize that there are two different genotypes that correspond to “gray with long ears”? (BW TT and BW Tt) ● Did you recognize that even though the two BW Tt categories have the same genotype, they contribute twice to the ratio? One category receives the T allele from the mother, the other category from the father. This is where a Punnett square can be particularly helpful. 59) C
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Clarify Question ● What is the key concept addressed by the question?● This question seems to be asking about a cross involving two genes, similar to Mendel’s dihybrid cross. But in fact, does the coat color gene need to be considered to answer the question? Since the question addresses only the ear phenotype, you can ignore the coat color gene entirely. Remember, for unlinked genes one gene does not affect the assortment of the other. So you can treat this as a cross between two heterozygotes for the ear length gene – a monohybrid cross. ● What type of thinking is required?● This question requires you to Analyze the information to determine the genotype ratio of the offspring. ● What key words does the question contain?● Pay close attention to the description of the alleles. The dominant allele will exhibit its phenotype in the hybrid, but the recessive allele will exhibit its phenotype only when homozygous. The two genes assort independently – this tells you that they are either on separate chromosomes or far apart on a chromosome, and the alleles end up in the gametes randomly. If a gamete gets a T allele, it could also get either a B or a W from the other gene. ● Don’t be confused by the gene abbreviations. The abbreviation for the ear length gene is T or t. For the fur gene, however, the abbreviations are different letters: B or W. From the question, though, we know that these are alleles of the same gene. So there are two genes in this scenario: the ear length gene T/t, and the fur color gene B/W. Since the question only asks about the long-ear genotype, you can ignore the B/W gene. Gather Content ● What do you already know about monohybrid crosses?● You may recall that monohybrid crosses produce a 3:1 phenotype ratio, and a Version 1
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1:2:1 genotype ratio. What does this question ask you to determine? (genotype ratio) Consider Possibilities ● What other information is related to the question? Which information is most useful?● Punnett squares are a useful way to determine both genotype and phenotype ratios. ● What is the genotype of the parental rabbits heterozygous for ear length? (Tt) ● What is the genotype of the offspring in question with long ears? (TT or Tt) Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Try drawing a Punnett square. Write the possible gametes on the top and the side. ● The gametes for both heterozygous parents are T and t. (Remember, we can ignore the fur color gene to answer this question.) ● This creates 4 categories of offspring: TT, Tt, tT, and tt. Even though Tt and tT are the same genotype, they constitute 2 of the 4 categories, because one is T (maternal) t (paternal) and the other is t (maternal) T (paternal). ● Of the four categories, which have long ears? (TT, Tt, and tT) ● So, considering JUST the long-eared offspring, what proportion of them will be homozygous TT? One of the three categories. So 1/3 of long-eared offspring are homozygous. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Version 1
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This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you use a pen and paper to help with this question? ● Did you diagram the categories of offspring with a Punnett square? ● Did you recognize that you could ignore fur color to answer the question? ● Did you recognize that even though the two Tt categories have the same genotype, they contribute twice to the ratio? One category receives the T allele from the mother, the other category from the father. This is where a Punnett square can be particularly helpful. ● Did you realize that you should answer the proportion of just the longeared offspring, not all offspring? You can still use the Punnett square ratios – just ignore the short-eared tt category, and determine how many of the three remaining categories are homozygous (one). 60) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses blood type alleles. ● What type of thinking is required?● You need to Analyze the information given to determine which baby goes with which parents. ● What key words does the question contain?● Remember, the blood types (A, B, AB, and O) are the phenotypes. They result from genotype combinations of the alleles IA, IB, and i. Gather Content ● What do you already know about blood type alleles?● Blood type alleles can be recessive (i) or co-dominant (IA and IB). ● Some blood types are specified by a single genotype (e.g., blood type O is always i i), but some can be specified by two possible genotypes (blood type A could be IA IA or IA i). Consider Possibilities ● What other information is related to the question? Which information is most useful?● The A and B parents could each be homozygous or heterozygous with an i allele. ● They could have produced the blood type O baby by contributing their i alleles. They could have produced the B baby by contributing an i and a IB allele. Or they could have produced the AB baby by contributing the IA and IB alleles. ● We need to figure out the other combinations to answer the question! Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Let’s consider each of the babies in turn: Version 1
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● The baby of blood type O must have received two i alleles. What parents are possible? (A and B, A and A, or B and O) ● The baby of blood type B must have received alleles IB and i (since there aren’t two B parents). What parents are possible? (A and B, or B and O) ● The baby of blood type AB must have received alleles IA and IB. What parents are possible? (only A and B!) So we can assign the AB baby to parents A and B. ● We can now determine that the baby of blood type B must be from the B and O parents, and finally the only parents left for the O baby are the A and A parents, who must have each contributed an i allele. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that the A and B parents could in theory have produced any of the babies (by contributing one or more i alleles)? ● Did you use a pencil and paper to help work out this question? 61) A 62) Section Break 62.1) C
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Clarify Question ● What is the key concept addressed by the question?● This question focuses on allele dominance relationships. ● What type of thinking is required?● You must Evaluate the information, and decide the most likely explanation. ● What key words does the question contain?● Key terms are in the answer choices: recessive, dominant, incomplete dominant, and codominant. A dominant allele will predominate over a recessive allele in a heterozygote; we see the dominant phenotype. A recessive trait is only exhibited in the recessive homozygote. An incompletely dominant trait shows an intermediate phenotype in the heterozygote. A codominant trait is one where two different alleles are both exhibited in the heterozygote phenotype, such as blood type. Gather Content ● What do you already know about allele dominance relationships?● You know that many genes have alleles with a dominant/recessive relationship. In a heterozygote, the dominant trait is seen. Some genes are codominant, and the heterozygote phenotype is an expression of both alleles. Other genes are incompletely dominant, with the heterozygote in-between two extremes. Consider Possibilities ● So which dominance relationship best matches the data?● The most important result is the cross between secretor and non-secretor. This would produce a heterozygote. Since the heterozygote phenotype is “secretor”, what does this suggest? Version 1
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Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Since the secretor phenotype is expressed in the heterozygote, the allele for that trait is dominant. This is also consistent with the results of the last cross – a monohybrid cross that produces a 3:1 phenotype ratio. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to weigh and judge evidence – to Evaluate – and choose the best of the possible answers. ● When reading a question, don’t let details like gene names distract you. To determine whether a trait is dominant, recessive, codominant, or incompletely dominant simply depends on whether the phenotype is exhibited in the heterozygote. 62.2) B
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Clarify Question ● What is the key concept addressed by the question?● This is basically a monohybrid cross like that seen in the text for Mendel’s purple pea flowers. ● What type of thinking is required?● You need to Apply what you know about monohybrid crosses and the use of Punnett squares. ● What key words does the question contain?● The genotypic ratio is the ratio of genotypes: that is, distinct allele combinations. Genotypes may be different even if they produce the same phenotype. Gather Content ● What do you already know about this type of cross?● This last cross is of two people heterozygous for one gene – a monohybrid cross. This is similar to the cross of purple-flowered pea plants in the text. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Punnett squares are a useful way to determine both genotype and phenotype ratios. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● You could do this in your head, but drawing a Punnett square on scrap paper is an easier approach. Write the possible parental gametes along both the top and side: seS and seNS. Fill in the 4 combinations. Note that two are the same, seS/seNS – thus we get a 1:2:1 ratio. Version 1
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Apply your knowledge and understanding to this unfamiliar situation. ● If you chose the answer “3:1”, think about the difference between and genotypic ratio and a phenotypic ratio. 63) Section Break 63.1) A
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Clarify Question ● What is the key concept addressed by the question?● This question asks about a complex example of one allele that is both recessive and dominant, for different traits. ● What type of thinking is required?● This question requires you to Analyze the information to predict an outcome. ● What key words does the question contain?● Cy is the abbreviation for the Curly gene. The mutant allele is both recessive – trait exhibited only in the homozygote – and dominant – trait exhibited in the heterozygote. It is recessive for lethality – that is, when homozygous the flies do not survive to adulthood. It is dominant for wing shape. Heterozygotes have curly wings. Gather Content ● What do you already know about dominant and recessive alleles?● You know that dominant alleles are exhibited in the heterozygote, and recessive alleles are exhibited only in the homozygote. Perhaps you did not know that one allele can be both recessive and dominant, for different traits! ● There are other examples of genes that can be both recessive and dominant. One is the mutation for Manx cats. When heterozygous, they have missing tails. But when homozygous, kittens die in utero. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Don’t let the complexity throw you. Simply write out the cross: Cy / Cy+ x Cy / Cy+ ● Now, you may be able to do this in your head. If not, what approach could you use to see all the categories of offspring? Version 1
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Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Try drawing a Punnett square. The gametes are Cy and Cy+ on the top and the side. ● The combinations in the offspring are thus Cy / Cy (dead), Cy / Cy+ (curly wings, alive), Cy+ / Cy (curly wings, alive), and Cy+ / Cy+ (straight wings, alive). ● So the two phenotypes seen in adults are curly wings and wild type (straight wings). Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. ● Writing down the cross is helpful with questions like these. Even better, draw the Punnett square.
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Chapter 13 13e CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 1) Pedigrees are useful to geneticists because they can help determine: Check all that apply. A) the mode ofinheritance for a particular trait. B) the genotype of aparticular individual. C) the probabilitythat future offspring will inherit a particular trait. D) whether aparticular trait is dominant or recessive.
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 2) A genetic_________blank indicates the distances between gene loci measured in terms of the frequency of recombination. A) map B) profile C) pedigree D) clone E) karyotype
3) Of the 23 pairs of human chromosomes, 22 pairs are homologous and are found in both males and females. These are called_________blank. A) bivalents B) autosomes C) recombinantchromosomes D) somaticchromosomes
4) Traits that are controlled by genes located on the X chromosome are said to be_________blank.
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A) autosomal B) gametal C) sex-linked D) pleiotropic
5)
Allele pairs are most likely to assort independently of one another when A) they controlunrelated traits. B) they controlrelated traits. C) they are on thesame chromosome. D) they are sex-linked. E) they are on different chromosomes.
6) The number of allele pairs that assort independently in an organism is generally much higher than the number of chromosome pairs. This phenomenon is due to A) independent assortment. B) segregation. C) crossing over. D) sex-linkage. E) chromosomeinactivation.
7)
The theory of chromosomal inheritance was first proposed by A) Mendel. B) Morgan. C) Knight. D) Sutton. E) Stern.
8)
In Drosophila, the sex of an individual is determined by
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A) 1 pair ofalleles. B) the number of Xchromosomes. C) the number of Ychromosomes. D) 1 pairof autosomes. E) 2 pairs of alleles.
9)
In Morgan's experiments, the white eye allele in Drosophila was shown to be A) located on the Xchromosome. B) located on the Ychromosome. C) dominant. D) located on anautosome. E) codominant.
10) The geneticist who discovered the white eye mutation in Drosophila and helped establish that genes are carried on chromosomes was A) Mendel. B) Sutton. C) Sturtevant. D) Janssens. E) Morgan.
11)
Genetic exchange between two homologous chromosomes is called A) synapsis. B) pleiotropy. C) crossing over. D) allelic exchange. E) independentassortment.
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12) Occasionally, chromosomes fail to separate during meiosis, leading to daughter cells that have an atypical number of chromosomes. This phenomenon is called A) epistasis. B) nondisjunction. C) crossingover. D) pleiotropy. E) chromosomeinactivation.
13)
The loss one copy of an autosome is called A) haploid. B) trisomic. C) bisomic. D) monosomic. E) monoploid.
14) In humans, individuals with trisomy of the _________blank chromosome are most likely to survive until adulthood. A) 3rd. B) 13th. C) 15th. D) 18th. E) 21st.
15)
If a human female has 2 Barr bodies per cell, it is almost certain that A) her father had 1Barr body per cell. B) her mother alsohad 2 Barr bodies per cell. C) she developed from a fertilized egg with 3 X chromosomes. D) she is genetically a male with female characteristics. E) she is genetically a fertile female.
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16)
A human female with only one X chromosome is said to have a condition called A) X chromosomeinactivation. B) Angelmansyndrome. C) Turner syndrome. D) Klinefelter syndrome. E) Down syndrome.
17)
The most common fatal genetic disorder of caucasians is A) cholera. B) cystic fibrosis. C) hemophilia. D) sickle cell anemia. E) muscular dystrophy.
18)
In sickle cell anemia, the hemoglobin differs from typical hemoglobin by A) the color of the pigment. B) the size of the molecule. C) a single amino acid substitution. D) the total number of amino acids. E) the type of blood cell it is found in.
19)
Hemophilia is caused by a A) recessive alleleon the X chromosome. B) dominant allele onthe X chromosome. C) codominant alleleon the X chromosome. D) recessive alleleon an autosome. E) dominant allele onan autosome.
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20) _________blank is a human hereditary disease that is caused by a dominant allele but does not show up in affected individuals until they are in middle age. A) Cystic fibrosis B) Sickle cell anemia C) Tay-Sachs disease D) Huntington's disease E) Hemophilia
21)
Amniocentesis is a procedure that is normally used A) to reduce the risk of genetic disease. B) for gene therapy. C) to change the sex of the fetus. D) for diagnosis of genetic disorders. E) for nourishing the fetus.
22) Huntington's disease is caused by a single dominant allele. It is a lethal disease, yet it persists in the human population. Which of the following statements best describes why? A) Huntington's disease is sex-linked and every human has at least one X chromosome; thus, the chances are extremely high for this allele to be maintained in the human population. B) Huntington'sdisease can present symptoms so mild that they appear to lack dominantexpression of the allele in some individuals; in those cases, the alleleis passed on to the offspring. C) While lethal to a parent, Huntington's disease will not be lethal to the offspring since it can skip a generation. D) Huntington'sdisease presents symptoms in mid-life, after most people have already hadoffspring. E) Even thoughHuntington's disease is lethal, it improves chances for reproduction before theperson dies.
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23) In humans, the male has an X and a Y sex chromosome. The human female has two X chromosomes. In birds, the female has a Z and a W sex chromosome while the male has two Z chromosomes. Which of the following statements is accurate about which parent determines the gender of the offspring based on inheritance of the necessary sex chromosome? A) In humans andbirds, the male determines the gender of all the offspring. B) In humans andbirds, the female determines the gender of all the offspring. C) In humans, themale determines the gender of the offspring, and in birds the female determinesthe gender. D) In humans, thefemale determines the gender of the offspring, and in birds the male determinesthe gender. E) Determination ofthe gender of any human or bird offspring is related to the environmentalconditions at the time of conception.
24)
Sickle cell anemia is caused by a defect in the A) oxygen-carryingpigment hemoglobin. B) ability of theblood to clot. C) abilityof red blood cells to fight infection. D) chloride iontransport protein.
25)
How many Barr bodies does a normal human female contain in each diploid cell? A) 0 B) 1 C) 2 D) 3
26)
A test cross can be used to do all of the following except
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A) determine whether an individual that displays a dominant phenotype is homozygous for the trait. B) determine whether an individual that displays a dominant phenotype is heterozygous for the trait. C) gather genotype information from phenotype information. D) identify the chromosome on which a gene is located.
27)
Which of the following animals is a genetic male? A) Bird - ZW B) Grasshopper - XO C) Honeybee - diploid D) Drosophila - XXY
28) In humans, if nondisjunction led to an individual with a genotype of XO, that person would A) be female becauseeach cell lacks a Y chromosome. B) be male becauseeach cell has only one X chromosome. C) display both male and female characteristics. D) not survive.
29) In humans, if nondisjunction led to an individual with a genotype of XXY, that person would A) be female becauseeach cell has two X chromosomes. B) be male becauseeach cell has one Y chromosome. C) display both male and female characteristics. D) not survive.
30)
Any genetic differences between individuals in a population are called
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A) markers. B) alleles. C) polymorphisms. D) SNPs.
31)
The classic experiments performed by Creighton and McClintock in Maize
A) provided theinitial evidence for genetic recombination. B) provided evidencethat genes located on the same chromosome do not assort independently. C) allowed for the establishment of the first genetic map. D) provided evidencefor the physical exchange of genetic material between homologues.
32)
Which statement about calico cats is false? A) Calico cats can be male or female. B) The different colored fur is due to the inactivation of one X chromosome. C) The variation in coat color is an example of an epistatic interaction. D) Calico cats are genetic mosaics.
33) Which offspring inherit all their mitochondrial DNA from their mother and none from their father? A) Daughters B) Sons C) Both sons and daughters D) Neither sons nor daughters
34)
Nondisjunction of a single pair of autosomes can lead to all of the following except
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A) aneuploidy. B) monosomy. C) trisomy. D) euploidy.
35)
If you needed to determine the order of genes on a chromosome, you should perform A) a test cross. B) a two-point cross. C) a three-point cross. D) a SNP test.
36) A 39-year-old woman and 42-year-old man are expecting a child; the woman is 6 weeks pregnant. The pregnancy is categorized as high risk due to the age of the parents, and the couple would like to have prenatal testing done to see if any genetic disorders are present in the fetus. Their doctor should suggest A) amniocentesis. B) genetic counseling. C) chorionic villi sampling. D) a pedigree analysis.
37) In Drosophila, dosage compensation is controlled by the male-specific lethal (MSL) complex consisting of MSL proteins and roX RNAs. Based on what you know about dosage compensation, the role of the MSL complex in males would be to A) double the levelof expression of genes on the X chromosome. B) increase the levelof expression of genes on the X chromosome by 50%. C) decrease the levelof expression of genes on the X chromosome by 50%. D) decrease the levelof expression of genes on the X chromosome by 100%. E) double the level of expression of geneson the Y chromosome.
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38) What is the relationship between recombination frequency and the actual physical distance on a chromosome? A) As physicaldistance increases, the recombination frequency increases in a linearfashion. B) As physicaldistance increases, the recombination frequency decreases in alinear fashion. C) As physicaldistance increases, the recombination frequency first increases in a linearfashion, but gradually levels off to a frequency of 0.5. D) As physical distance increases, the recombination frequency first decreases, but then increases.
39) In a two-point cross to map genes A and B, you obtained 98 recombinant types and 902 parental types among the offspring. How far apart are these genes? A) 9.8 cM B) 0.98 cM C) 90.2 cM D) 9.02 cM E) .098 cM
40) Morgan's student Sturtevant demonstrated that the recombination frequencies between a series of linked genes is additive. Examine the following recombination data from Sturtevant and determine the proper order of the genes on the Drosophila X chromosome. Assume y is in the 0.0 position. Gene 1
Gene 2
Recomination frequency
yellow (y)
vermilion (v)
0.322
vermilion (v)
miniature(m)
0.030
white(w)
vermilion (v)
0.297
yellow (y)
white(w)
0.010
white(w)
miniature(m)
0.337
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A) y m v w B) y w v m C) y m w v D) y w m v
41) In some human populations, the proportion of individuals who are heterozygous for the sickle cell allele is much higher than would be expected by chance alone. Why? A) Individuals with two normal alleles have an advantage over heterozygous individuals. B) Individuals with two sickle cell alleles have an advantage over heterozygous individuals. C) Individuals with two sickle cell alleles have an advantage over individuals with two normal alleles. D) Heterozygous individuals have an advantage over individuals with two normal alleles.
42) A deletion of a particular stretch of chromosome 15 can cause either Prader-Willi syndrome or Angelman syndrome, depending on A) the parental origin of the normal and deleted chromosome. B) whether or not the region is methylated properly. C) whether a translocation event has occurred. D) whether a nondisjunction event has occurred.
43) How did the development of anonymous markers, such as short tandem repeats, aid in the production of a human genetic map?
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A) Anonymous markers are genetic markers that do not cause a detectable phenotype, but can be detected by molecular techniques. The markers correspond to specific and unique chromosomal regions, thereby allowing for the identification and ordering of particular segments of DNA. Such information was essential to the generation of a human genetic map. B) Anonymous markers are genetic markers that cause a detectable phenotype and can't be detected by molecular techniques. The markers correspond to specific and unique chromosomal regions, thereby allowing for the identification and ordering of particular segments of DNA. Such information was essential to the generation of a human genetic map. C) Anonymous markers are genetic markers that do not cause a detectable phenotype, but can be detected by molecular techniques. The markers correspond to specific and unique genetic regions, thereby allowing for the identification and ordering of particular segments of the chromosome. Such information was essential to the generation of a human genetic map.
44)
Why isn't mitochondrial DNA a unique identifier?
A) Mitochondrial DNA is inherited through the paternal lineage. All offspring inherit their father's mitochondria, and therefore the same mitochondrial DNA. As a result, all family members that share a paternal lineage would have the same mitochondrial DNA. Mitochondrial DNA can therefore be used to confirm or eliminate a person's relationship within a paternal line, but cannot be used to identify a specific individual. B) Mitochondrial DNA is inherited through the maternal lineage. All offspring inherit their mother's mitochondria, and therefore the same mitochondrial DNA. As a result, all family members that share a maternal lineage would have the same mitochondrial DNA. Mitochondrial DNA can therefore be used to confirm or eliminate a person's relationship within a maternal line, but cannot be used to identify a specific individual. C) Mitochondrial DNA is inherited through the maternal lineage. All female offspring inherit their mother's mitochondria, and therefore the same mitochondrial DNA. As a result, all female family members that share a maternal lineage would have the same mitochondrial DNA. Mitochondrial DNA can therefore be used to confirm or eliminate a person's relationship within a maternal line, but cannot be used to identify a specific individual.
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45) Suppose you are carrying out a series of crosses with an insect where the mechanism of sex determination is unknown. You discover a mutant female with short bristles and decide to cross it with a wild type male that has normal bristles. Half of the F1 progeny have short bristles but all of these short-bristled F1 progeny are males. Based on these results, a valid hypothesis would be A) males are ZW, females are ZZ, and short bristles are caused by a dominant allele on the Z chromosome. B) males are ZZ, females are ZW, and short bristles are caused by a recessive allele on the Z chromosome. C) males are ZZ, females are ZW, and short bristles are caused by a dominant allele on the W chromosome. D) males are ZZ, females are ZW, and short bristles are caused by a dominant allele on the Z chromosome.
46) In 1910, Morgan did a series of experiments with the fruit fly Drosophila, an organism where females are XX and males are XY. When a mutant male fly with white eyes was crossed with a wild type female with red eyes, none of the F1 progeny had white eyes but 18% of the F2 progeny had white eyes. Unexpectedly, all of these white-eyed F2 flies were males. Based on these results, Morgan concluded that white eyes is caused by a recessive X-linked allele. Suppose Morgan had found that half of the F1 progeny had white eyes but all of these whiteeyed F1 flies were females. In this case, a valid hypothesis would be A) white eyes is caused by a recessive Y-linked allele. B) white eyes is caused by a dominant Y-linked allele. C) white eyes is caused by a dominant X-linked allele. D) white eyes is caused by a dominant autosomal allele.
47) Genetic maps are based on recombination frequencies. Because both odd and even numbers of crossovers can occur between any two gene loci, as the physical distance between two loci increases, the maximum recombination frequency levels off at 50%. However, suppose you discovered a species where only an even number of crossovers can occur between any two gene loci. In this case, as the physical distance between two loci increases, you would expect the maximum recombination frequency to
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A) be zero. B) increase with no limit. C) level off at 25%. D) level off at 75%. E) level off at 100%.
48) When viewing a human pedigree for a particular genetic condition, you observe that affected individuals appear in some generations, but not in others. This suggests the condition is_________blank. A) dominant B) sex-linked C) pleiotropic D) epistatic E) recessive
49) _________blank is the study of complex, quantitative traits to identify their underlying genetic components. A) Genome sequencing B) Genome-wide association study C) Genetic mapping D) Genetic heritability analysis
50) Phenotype-wide association study (PheWAS) is dependent on large amounts of medical data because_________blank.
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A) very few patients have the genomes that can be used in association studies B) it uses the genetic data of many patients to associate the resultant phenotypes with specific genotypes C) it identifies rare patients with many genetic mutations to associate multiple phenotypic conditions at one time D) it uses the phenotypes of many patients (e.g. medical conditions) to identify the likely genes responsible
FILL IN THE BLANK. Write the word or phrase that best completes each statement or answers the question. 51) In humans, hemophilia is caused by a recessive allele on the X chromosome. Suppose a man with hemophilia has children with a woman who doesn't have hemophilia but whose mother had hemophilia. What is the probability that their second child will have hemophilia? (Enter the probability as a percent. Enter the number only without the percent sign. For example, enter 100% as 100 and enter 12.5% as 12.5)
52) In humans, hemophilia is caused by a recessive allele on the X chromosome. Suppose a man with hemophilia has children with a woman who doesn't have hemophilia but whose mother had hemophilia. If an ultrasound test shows that their first child is female, what is the probability that she has hemophilia? (Enter the probability as a percent. Enter the number only without the percent sign. For example, enter 100% as 100 and enter 12.5% as 12.5 )
53) In the fruit fly Drosophila, there is a dominant gene for normal wings and its recessive allele for vestigial wings. At another gene locus on the same chromosome, there is a dominant gene for red eyes and its recessive allele for purple eyes. A male that was heterozygous at both gene loci was mated with a female that was homozygous for both recessive alleles and the following results were observed among the offspring: Normal wings and red eyes - 420 Vestigial wings and red eyes - 80 Normal wings and purple eyes - 70 Vestigial wings and purple eyes - 430 According to these data, what is the distance, in centimorgans, between these 2 gene loci? (Enter the number only without the units. For example, 100 cM would be entered as 100)
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54) In fruit flies ( Drosophila melanogaster) there is a dominant allele for red eyes and a recessive allele for white eyes. These alleles are located on the X chromosome. If a heterozygous red-eyed female is mated with a white-eyed male, what percentage of the offspring are expected to be white-eyed females? (Enter the number only without the percent sign. For example, enter 100% as 100 and enter 12.5% as 12.5)
55) At an autosomal gene locus in humans, the allele for brown eyes is dominant over the allele for blue eyes. At another gene locus, located on the X chromosome, a recessive allele produces colorblindness while the dominant allele produces normal color vision. A heterozygous brown-eyed female who is a carrier of color blindness has children with a blue-eyed male who is not colorblind. What is the probability that their first child will be a blue-eyed female who has normal color vision? (Enter the probability as a percent. Enter the number only without the percent sign. For example, enter 100% as 100 and enter 12.5% as 12.5)
56) At an autosomal gene locus in humans, the allele for brown eyes is dominant over the allele for blue eyes. At another gene locus, located on the X chromosome, a recessive allele produces colorblindness while the dominant allele produces normal color vision. A heterozygous brown-eyed female who is a carrier of colorblindness has a child with a blue-eyed male who is not colorblind. An ultrasound test shows that the child is female. What is the probability that she will be colorblind? (Enter the probability as a percent. Enter the number only without the percent sign. For example, enter 100% as 100 and enter 12.5% as 12.5)
SECTION BREAK. Answer all the part questions. 57) In Drosophila, the allele red eyes (bw+) is dominant to the allele for brown eyes (bw). At another gene locus on the same chromosome, the allele for thin wing veins (hv+) is dominant to the allele for heavy wing veins (hv). Flies homozygous for bw and hv+ are crossed to flies homozygous for bw+ and hv to obtain doubly heterozygous F1 progeny.
57.1) Given that these two gene loci are very closely linked, the genotypic ratio in the F2 generation should be closest to
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A) 1:2:1 B) 1:1:1:1 C) 9:3:3:1 D) 3:1
57.2) Given that these two gene loci are very closely linked, the phenotypic ratio in the F2 generation should be closest to A) 1 brown eye, heavy wing veins: 2 red eye, thin wing veins: 1 brown eye, thin wing veins B) 1 brown eye, thin wing veins: 2 red eye, thin wing veins: 1 red eye, heavy wing veins C) 3 red eye, thin wing veins: 1 brown eye, heavy wing veins D) 1 brown eye: 1 red eye: 1 heavy wing veins: 1 thin wing veins
57.3)
What would be the results of a test cross with the F1 flies?
A) 1 brown eye, thin wing veins: 1 red eye, heavy wing veins B) 1 brown eye, heavy wing veins: 1 red eye, thin wing veins C) 1 brown eye, thin wing veins: 2 red eye, thin wing veins: 1 red eye, heavy wing veins D) 1 brown eye, heavy wing veins: 2 red eye, thin wing veins: 1 red eye, thin wing veins
58) You are a forensic technician working on a DNA sample obtained from a crime scene. Your job is to compare the unknown DNA sample with known DNA samples collected from five different suspects. Preliminary analysis using only a few DNA markers revealed that the unknown sample could possibly match two of the suspects. After consulting the case file, you find out that these two suspects are brothers (but not twins). You realize that you will have to do a more detailed analysis on the samples so that you can distinguish between the brothers and determine which brothers' DNA matches the unknown sample.
58.1)
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A) single nucleotide polymorphisms (SNPs) B) human genome map C) linkage data D) markers on the Y chromosome
58.2)
Why can't you use mitochondrial DNA to distinguish between these two suspects?
A) The sequence of mitochondrial DNA has not yet been determined. B) The brothers sharethe same mitochondrial DNA. C) There are no molecular techniques available that allow one to analyze mitochondrial DNA. D) Because mitochondrial DNA is inherited in a paternal pattern.
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Answer Key Test name: Chap 13_13e_Raven 1) [A, B, C, D] 2) A 3) B 4) C 5) E 6) C 7) D 8) B 9) A 10) E 11) C 12) B 13) D 14) E 15) C 16) C 17) B 18) C 19) A 20) D 21) D 22) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses Huntington’s disease. ● What type of thinking is required?● This answer requires you to weigh and judge evidence – to Evaluate – and choose the best of the possible answers. ● What key words does the question contain?● Huntington’s disease is a human disease caused by a dominant allele. That is, the disease phenotype occurs in heterozygotes. Hungtington’s is a lethal disease that causes death of the patient. Gather Content ● What do you already know about Huntington’s disease?● Huntington’s disease is caused by an autosomal dominant allele – that is, an allele on a non-sex chromosome. ● Huntington’s leads to symptoms in middle age, due to degeneration of brain cells. This leads to neurological symptoms including involuntary movements and poor muscle function. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Huntington’s is not sex-linked, it is autosomal. Moreover, detrimental alleles on the X chromosome can still be selected against, just like any other chromosome. That option doesn’t make sense. ● Some diseases are mild in some individuals – they have incomplete penetrance. But in this case Huntington’s has a typical dominant phenotype. So the explanation is not due to lack of a phenotype in some people. ● Huntington’s does not “skip a generation”. That phrase generally Version 1
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refers to recessive alleles that only create a phenotype in the homozygote. Huntington’s is dominant. ● Huntington’s does not create any kind of reproductive advantage. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Huntington’s like many neurodegenerative diseases, arises slowly as damage accumulates. Symptoms typically occur in middle age – after age 35. ● When do people typically have children? Usually before that age. So the disease does not have a strong impact on reproduction. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This answer required you to weigh and judge evidence – to Evaluate – and choose the best of the possible answers. ● Did you remember the two key details about Huntington’s disease? The symptoms occur in middle age, and it is inherited as an autosomal dominant gene. ● The description “lethal” for a gene can mean a variety of things. Some mutations are lethal and the fetus will fail to develop. Others create a lethal disease only late in life. How will selection differ for these two types of genes? ● As genetic testing and preimplantation genetic diagnosis are becoming more common, how do you expect the prevalence of the Huntington’s disease gene to change? 23) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses sex determination. ● What type of thinking is required?● Although you may not have seen this example before, you know enough about the concept to Apply your knowledge and understanding to this unfamiliar situation. ● What keywords does the question contain?● Sex chromosomes are the chromosomes that determine the sex of offspring. X and Y are the names of the sex chromosomes in some animals. When the female carries different sex chromosomes, they are called Z and W. Gather Content ● What do you already know about sex determination?● In humans, the Y chromosome determines maleness, due to the SRY gene. ● In some fish and reptiles, sex is determined by environmental factors like temperature. ● In birds, the female is the heterogametic sex – she carries two different sex chromosomes. In those species the female is ZW and the male is ZZ. Consider Possibilities ● Consider the different answer options. Which can you rule out?● In both humans and birds, sex is determined by the chromosomes, not the environment, so we can rule out that option. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Write out the gametes produced by a human male and female. ● The male produces half X gametes and half Y gametes. The femaleonly produces X gametes. Version 1
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● So the baby always receives an X from the mother. If she gets another X from her father she will become a girl; if he gets a Y from his father he will be a boy. ● Thus we say the male’s contribution determines the gender. ● The opposite is true for birds. The male always contributes a Z gamete. So the gender of the offspring is determined by whether the female contributed a Z or W. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Apply your knowledge and understanding of sex determination to answer the question. ● Did you understand that sex is decided by the contribution of one particular parent? ● Did you consider the types of gamete each parent produces? 24) A 25) B 26) D 27) B 28) A 29) B 30) C 31) D 32) A 33) C 34) D 35) C 36) C Version 1
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37) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses dosage compensation. ● What type of thinking is required?● Although you may not have seen this example before, you know enough about dosage compensation to Apply your knowledge and understanding to this unfamiliar situation. ● What key words does the question contain?● Dosage compensation is the process that ensures an equal level of expression from the sex chromosomes despite a differing number of sex chromosomes in males and females. The MSL complex and roX RNAs are the names of genes that participate in the process in fruit flies. Gather Content ● What do you already know about dosage compensation?● Dosage compensation is the process that ensures an equal level of expression from the sex chromosomes despite a differing number of sex chromosomes in males and females. ● If there were no dosage compensation, females would have twice the level of X-linked gene expression as males. ● This would create problems in the cell, because the products of Xlinked genes have to work in the correct proportions with the products of autosomal genes. Consider Possibilities ● Consider the different answer options. Which can you rule out?● There are few genes on the Y chromosome, and most of those are on the X as well (in the pseudo-autosomal region). So dosage compensation does not affect Y-linked genes. Choose Answer Version 1
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● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● So for male fruit flies, would dosage compensation need to increase or decrease gene expression? ● Flies use the XX/XY system, so male flies have one copy of the X chromosome. ● Therefore, male flies need to have increased gene expression relative to females. ● How much more expression do the males need to equal that of females (who have two X chromosomes)? ● Twice as much – so dosage compensation doubles the expression of X-linked genes. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Apply your knowledge and understanding about dosage compensation to this unfamiliar situation. ● Did you read carefully enough to understand that this question asked specifically about male fruit flies? ● Did you recognize that the function of dosage compensation is to equalize gene expression between the sexes? ● Did you realize that dosage compensation in flies uses a different mechanism than in mammals? In mammals, the dosage of the X is lowered in females, rather than raised in males. ● Why do you think the genes were named “male-specific lethals”? 38) C 39) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses a two-point mapping cross. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● A two-point cross is a cross involving the alleles of two genes. ● Recombinant types are chromosomes with new allele combinations, different than the parents carried. ● Parental types are chromosomes with the same allele combinations as the parents carried. Gather Content ● What do you already know about two-point mapping?● Genetic distances are described in centiMorgans (cM). ● One cM represents 1% recombination between the genes. ● Recombination events are recognized by counting the number of recombinant chromosomes. Consider Possibilities ● What other information is related to the question? Which information is most useful?● To calculate the distance in cM, just determine what % of progeny have recombinant chromosomes. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● From this cross, the progeny were 98 recombinant types and 902 parental types. ● 98 + 902 = 1000 total progeny ● Recombinant progeny = 98/1000 = 9.8/100 = 9.8% Version 1
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● Since 1 cM represents 1% recombination, we can say the distance is 9.8 cM. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked how many cM apart are genes A and B, based on the recombination between them. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the distance in centiMorgans is just the percent recombination? 40) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses recombination frequency. ● What type of thinking is required?● This answer requires you to weigh and judge evidence – to Evaluate – and choose the best of the possible answers. ● What key words does the question contain?● Linked genes are genes that lie near each other on a chromosome – near enough that they do not segregate independently. They will segregate together unless there is a recombination event between them, which takes place at some frequency, depending on distance. This is the recombination frequency. Gather Content ● What do you already know about recombination frequency?● Recombination frequency reflects the distance between two genes. If the genes are close, the frequency will be low; if far apart, it will be higher, up to 0.5. ● The frequency between two genes will be the sum of the frequencies between those flanking genes and a middle gene (up to 0.5). Consider Possibilities ● What other information is related to the question? Which information is most useful?● For this problem, drawing a diagram can be helpful. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● We are told that yellow is at the 0.0 position – in other words, at the end of the chromosome, so start by drawing y on the left. ● What recombination data do we have for yellow and other genes? 0.322 between y and v, and 0.010 between y and w. So white is closer to yellow and vermilion is much further. ● Now you can draw y-w----------v. ● What other data do we have, to help place miniature? 0.030 between v and m, and 0.337 between w and m. So miniature is close to vermilion, and far from white. ● But is miniature between white and vermilion, or on the far side of vermilion? The recombination frequency is greater for white and miniature (0.337), than for white and vermilion (0.297), so miniature must be the furthest away. ● Thus: y-w----------v ---m, or y w v m. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the
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process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This answer requires you to weigh and judge evidence – to Evaluate – and choose the best of the possible answers. ● Did you recognize that recombination frequency reflects gene distance? ● Did you realize that recombination frequencies are additive? ● Did you draw a diagram to help you interpret the data?
41) D 42) A 43) A 44) B 45) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses “X-linked inheritance”, but in the context of the ZZ/ZW sex determination system. ● What type of thinking is required?● This answer requires you to weigh and judge evidence – to Evaluate – and choose the best of the possible answers. ● What key words does the question contain?● Sex determination is the mechanism by which the biological sex of the individual is specified. Gather Content ● What do you already know about sex determination systems?● Remember, there are two common types of chromosomal sex determination systems: XX/XY and ZZ/ZW. ● In the ZZ/ZW system, the female is the heterogametic sex, with Z and W chromosomes. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Looking at the answer options, we see they all involve the ZZ / ZW system. ● You may recall that in the ZZ / ZW system, it is the females that are ZW. (Otherwise we just call it XX and XY.) So you can rule out the answer that says males are ZW. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● If the insect uses the ZZ / ZW system, then the female (with the short bristles) is ZW. The short bristles allele is likely on the Z. Let’s call her genotype ZS / Version 1
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W. ● So the male with normal bristles is Z+/ Z+. ● Only the sons exhibit the short bristles phenotype. ● Yet they are ZS/ Z+. Therefore the mutant allele is dominant. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to weigh and judge evidence – to Evaluate – and choose the best of the possible answers. ● Did you remember that in the ZZ / ZW system, males are ZZ? ● Did you try writing out the cross to help answer the question? ● Are there other possible explanations? Could the allele have been on the W chromosome? Could the allele have been on an autosome? 46) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses X-linked inheritance. ● What type of thinking is required?● This answer requires you to weigh and judge evidence – to Evaluate – and choose the best of the possible answers. ● What key words does the question contain?● Dominant alleles are expressed when heterozygous, but recessive alleles are expressed only when homozygous or on the only X chromosome in males (hemizygous). Gather Content ● What do you already know about X-linked inheritance?● X-linked genes have different patterns of gene expression because males have only the one X chromosome. ● Since females have two X chromosomes, they must always receive the one X chromosome from their father. Males always receive one of their mother’s X chromosomes, and the Y from their father. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Since the phenotype is only seen in one sex of the progeny, we can rule out the gene sitting on an autosome. If it was, both sexes would receive it equally. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Write out the imaginary cross (“Suppose...”) to answer this question. Call the whiteeyed allele w-, and the red allele w+. Version 1
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● The original male is w- / ?, and the female is w+/ w+. ● In this imaginary scenario, all the FEMALES of the F1 are whiteeyed. What would this mean? ● They would have received the mutant allele from the white-eyed father, so it would have to be on the X. Females never receive a Y – or they would become males! ● If the w- / w+ females exhibited the phenotype, that would mean that w- was dominant over w+. ● Thus, a dominant X-linked allele. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to weigh and judge evidence – to Evaluate – and choose the best of the possible answers. ● Did you remember that females never inherit the Y chromosome? ● Did you try writing out the cross to help answer the question? 47) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses recombination frequency. ● What type of thinking is required?● You need to Analyze the information given, using logic, to dissect the problem and determine the answer. ● What keywords does the question contain?● “Gene loci” refers to the location of genes on the chromosome. Recombination frequency is the percent of progeny with a recombined chromosome – that is, a set of alleles that differs from the original parental chromosomes. Gather Content ● What do you already know about recombination frequency?● Normally, the recombination frequency increases with distance because there is more physical room for the crossover of DNA strands to occur. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Drawing a diagram is a useful way to attack this problem. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Draw a chromosome pair with two genes, A and B on the top chromosome, and a and b on the bottom chromosome. ● If one crossover event occurs (draw an X between the chromosomes), you can now see that A and b are connected on one chromosome, and a and B are connected on the other chromosome. ● But if a second crossover event occurs (draw another X next to the Version 1
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first), the A allele is NOW connected to the B allele – just like the parental chromosome. ● So normally, as distance increases, the even-numbered crossover events re-connect the parental combination. This counteracts the effect of the first crossover. Eventually, at a large distance, only half the events will be odd-numbered, and thus “visible” in the progeny. ● What happens if ALL the events are even-numbered? Then the parental chromosomes will always result (A and B, and a and b). This would appear to be a 0% recombination frequency. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that double crossover events connect the genes like on the original chromosome? ● Did you try drawing a diagram to help answer the question? ● What if two genes always had exactly one crossover between them? How would they segregate? 48) E 49) B 50) B 51) 50
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Clarify Question ● What is the key concept addressed by the question?● This question addresses X-linked inheritance. ● What type of thinking is required?● Although you may not have seen this example before, you know enough about the concept to Apply your knowledge and understanding to this unfamiliar situation. ● What key words does the question contain?● Hemophilia is a disease that interferes with blood clotting. To answer this question, you just need to know that it is a recessive, X-linked disease. That is, it is due to a gene on the X chromosome, and the disease is only expressed when the allele is homozygous (in females) or hemizygous (on the only X, in males). Gather Content ● What do you already know about X-linked inheritance?● X-linked inheritance works differently than autosomal inheritance. For females, genes act similarly. But males only carry one X chromosome. ● Since males only carry one X, recessive disease genes on the X are more likely to be expressed. X-linked diseases are more common in males, and females are usually carriers. Consider Possibilities ● What other information is related to the question? Which information is most useful?● In this case, we are told that the mother’s mother had hemophilia. She must have been homozygous (since hemophilia is caused by a recessive allele). But her daughter is healthy. ● Therefore we know that the mother is a carrier of the gene – she is heterozygous. ● Punnett squares are a useful way to determine both genotype and phenotype ratios. Version 1
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Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Try drawing a Punnett square. Write the possible gametes on the top and the side. ● The gametes for the father are XH and Y. ● The gametes for the mother are XH and X+. ● There are 4 combinations of offspring : XH / Y, X+ / Y, XH / X+ and XH / XH. ● So whether boy or girl, in this case the child has a 50% chance of expressing the hemophilia phenotype. ● Whether it is the first child, the second child, or the tenth child, each child has the same probability. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Apply your knowledge and understanding to this unfamiliar situation. ● Did you remember that recessive X-linked genes are expressed in males that carry the allele? ● Did you recognize the information provided by knowing that the maternal grandmother had hemophilia? ● Did you try drawing a Punnett square to help answer the question? ● This example is unusual because the father has the disease and the mother is a carrier. So in this case the risk is equal for both males and females. In the population at large, though, we see X-linked diseases more commonly expressed in males. Why? 52) 50
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Clarify Question ● What is the key concept addressed by the question?● This question addresses X-linked inheritance. ● What type of thinking is required?● Although you may not have seen this example before, you know enough about the concept to Apply your knowledge and understanding to this unfamiliar situation. ● What key words does the question contain?● Hemophilia is a disease that interferes with blood clotting. To answer this question, you just need to know that it is a recessive, X-linked disease. That is, it is due to a gene on the X chromosome, and the disease is only expressed when the allele is homozygous (in females) or hemizygous (on the only X, in males). Gather Content ● What do you already know about X-linked inheritance?● X-linked inheritance works differently than autosomal inheritance. For females, genes act similarly. But males only carry one X chromosome. ● Since males only carry one X, recessive disease genes on the X are more likely to be expressed. X-linked diseases are more common in males, and females are usually carriers. Consider Possibilities ● What other information is related to the question? Which information is most useful?● In this case, we are told that the mother’s mother had hemophilia. She must have been homozygous (since hemophilia is caused by a recessive allele). But her daughter is healthy. ● Therefore we know that the mother is a carrier of the gene – she is heterozygous. ● Punnett squares are a useful way to determine both genotype and phenotype ratios. Version 1
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Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Try drawing a Punnett square. Write the possible gametes on the top and the side. ● The gametes for the father are XH and Y. ● The gametes for the mother are XH and X+. ● There are 4 combinations of offspring : XH / Y, X+ / Y, XH / X+ and XH / XH. ● So whether boy or girl, in this case the child has a 50% chance of expressing the hemophilia phenotype. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Apply your knowledge and understanding to this unfamiliar situation. ● Did you remember that recessive X-linked genes are expressed in males that carry the allele? ● Did you recognize the information provided by knowing that the maternal grandmother had hemophilia? ● Did you try drawing a Punnett square to help answer the question? ● This example is unusual because the father has the disease and the mother is a carrier. So in this case the risk is equal for both males and females. In the population at large, though, we see X-linked diseases more commonly expressed in males. Why? 53) 15
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Clarify Question ● What is the key concept addressed by the question?● This question addresses linkage mapping by recombination. ● What type of thinking is required?● Although you may not have seen this example before, you know enough about the concept to Apply your knowledge and understanding to this unfamiliar situation. ● What key words does the question contain?● Dominant alleles are expressed in the heterozygote; recessive alleles are only expressed in the homozygote. Centimorgans are a unit of map distance. 1 centimorgan is equivalent to a 1% recombination frequency. Gather Content ● What do you already know about linkage mapping by recombination?● Linkage mapping uses recombination frequencies as a proxy for distance along the chromosome. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Centimorgans are the unit of map distance. 1 centimorgan is equivalent to a 1% recombination frequency. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● To analyze the data, we should first determine which were the likely parental chromosomes in the father. Since vg+ pr+ / vg pr (normal wings and red eyes) and vg pr / vg pr (vestigial wings and purple eyes) are the most common classes, those are the original paternal chromosomes. ● So the recombinant chromosomes are vg pr+ / vg pr (vestigial wings and red eyes) and vg+ pr / vg pr (normal wings and purple eyes). Version 1
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● The recombinant chromosomes constitute the fraction of progeny: 80 + 70 / 420 + 80 + 70 + 430, or 150 / 1000. ● To determine the percentage recombination frequency, 150 / 1000 = 15 / 100 = 15%. ● Since 1% recombination = 1 cM, then 15% recombination is 15 cM. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Apply your knowledge and understanding to this unfamiliar situation. ● Did you remember that 1% recombination = 1 centimorgan? ● Did you recognize that you needed to determine which two classes were the recombinant classes? ● Did you determine the percent recombination using the equation : 80 + 70 / 420 + 80 + 70 + 430, or 150 / 1000? 54) 25
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Clarify Question ● What is the key concept addressed by the question?● This question addresses X-linked inheritance. ● What type of thinking is required?● Although you may not have seen this example before, you know enough about the concept to Apply your knowledge and understanding to this unfamiliar situation. ● What key words does the question contain?● Dominant alleles are expressed in the heterozygote; recessive alleles are only expressed in the homozygote. Gather Content ● What do you already know about X-linked inheritance?● X-linked inheritance works differently than autosomal inheritance. For females, genes act similarly. But males carry just one X chromosome and the other paired chromosome is the Y chromosome. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Punnett squares are a useful way to determine both genotype and phenotype ratios. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Try drawing a Punnett square. Write the possible gametes on the top and the side. ● The female gametes are w+ and w-. ● The male gametes are w- and Y. ● There are four combinations of offspring : w+/ w-, w-/ w- , w+/ Y and w-/ Y in equal ratios. ● So 25% of the offspring will be white-eyed females: w-/ w-. Version 1
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Apply your knowledge and understanding to this unfamiliar situation. ● Did you remember that the X chromosome is paired with the Y chromosome? ● Did you try drawing a Punnett square to help answer the question? 55) 25
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Clarify Question ● What is the key concept addressed by the question?● This question addresses both X-linked and autosomal inheritance. ● What type of thinking is required?● You need to Analyze the information given, using logic, to dissect the problem and determine the answer. ● What keywords does the question contain?● Autosomal refers to genes on a non-sex chromosome. X-linked genes are on the X chromosome, like the colorblindness gene here. Dominant alleles are expressed when heterozygous, but recessive alleles are expressed only when homozygous or on the only X chromosome in males (hemizygous). Gather Content ● What do you already know about X-linked and autosomal inheritance?● X-linked genes have different patterns of gene expression because males have only one X chromosome. ● The segregation of an allele on the X will not affect the segregation of an allele on an autosome. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Punnett squares are a useful way to determine both genotype and phenotype ratios. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Try drawing a Punnett square. Write the possible gametes on the top and the side. You will have to create your own abbreviations for the gene alleles. Version 1
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● Let’s call the colorblindness gene C and the eye color gene B. ● The mother is a carrier for colorblindness (C/c) and heterozygous for brown eyes (B/b). Her gametes are C B, C b, c B, and c b. ● The father is not colorblind (C/Y) and blue-eyed (b/b). His gametes are C b and Y b. ● This creates 8 combinations in the offspring. ● Consider just the ½ of the offspring which are female. The females are CC Bb, CC bb, Cc Bb, and Cc bb. Half of these females are blue-eyed, and ALL will have normal color vision. ● So ½ (female) x ½ (blue-eyed) x 1 (non-colorblind) = 1/4. or 25% ● You can also solve this with a simpler approach: ● ½ the offspring will always be female. Those females will ALL receive the C allele on the one X from their father. (A daughter always receives her father’s X chromosome, not the Y.) Of those females, half will get the blue-eyes allele from their mother (and guaranteed that allele from the homozygous recessive father). ● So ½ x 1 x ½ = ¼ or 25%. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that a daughter will always receive the X from her father? ● Did you try drawing a Punnett square, or at least writing out the cross, to help answer this question? 56) 0
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Clarify Question ● What is the key concept addressed by the question?● This question addresses both X-linked and autosomal inheritance. ● What type of thinking is required?● You need to Analyze the information given, using logic, to dissect the problem and determine the answer. ● What key words does the question contain?● Autosomal refers to genes on a non-sex chromosome. X-linked genes are on the X chromosome, like the colorblindness gene here. Dominant alleles are expressed when heterozygous, but recessive alleles are expressed only when homozygous or on the only X chromosome in males (hemizygous). Gather Content ● What do you already know about X-linked and autosomal inheritance?● X-linked genes have different patterns of gene expression because males have only the one X chromosome. ● Since girls have two X chromosomes, they must always receive the one X chromosome from their father. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Punnett squares are a useful way to determine both genotype and phenotype ratios. ● Do you need to worry about the eye color gene to answer this question? No! Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Try drawing a Version 1
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Punnett square. Write the possible gametes on the top and the side. You will have to create your own abbreviations for the gene alleles. ● Let’s call the colorblindness gene C. To answer this question, we can ignore the eye color gene. ● The mother is a carrier for colorblindness (C/c). Her gametes are C and c. ● The father is not colorblind (C/Y) . His gametes are C and Y. ● This creates four combinations in the offspring. ● Consider just the offspring which are female (since we know the child is a female). The females are CC or Cc. ● Since the colorblindness allele is recessive, both categories of females will have normal vision. There is a 0% chance of a daughter being colorblind. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that a daughter will always receive the X from her father? ● Did you try drawing a Punnett square, or at least writing out the cross, to help answer this question? 57) Section Break 57.1) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses genetic linkage. ● What type of thinking is required?● You need to Analyze the information given, using logic, to dissect the problem and determine the answer. ● What key words does the question contain?● This question describes two gene loci (singular is gene locus). Each gene’s abbreviation uses two letters – bw for brown and hv for heavy veins. The genotypic ratio refers to the alleles in the DNA, not to the physical phenotypes. Gather Content ● What do you already know about genetic linkage?● Genetic linkage refers to genes that lie close to each other on the chromosome. ● Because their loci are linked, they are not segregated by independent assortment. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Since the genes are linked, they do NOT segregate like typical unlinked genes. Therefore we would NOT expect the 9:3:3:1 answer which would be typical for two independent, unlinked genes. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Since the genes are tightly linked, we can approximate them as one Version 1
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gene. Let’s call the bw hv+ combination A, and the bw+ hv combination B. ● So the P cross is AA x BB... ● Creating the F1 double heterozygotes who cross together, AB x AB. ● This cross will produce four categories of offspring in the F2: AA, AB, BA, and BB. But AB and BA are the same genotypically. So the genotypic ratio is 1:2:1. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that you can treat the two tightly linked genes like a single gene? ● Did you write out the crosses and draw a Punnett square to determine the answer? 57.2) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses genetic linkage. ● What type of thinking is required?● You need to Analyze the information given, using logic, to dissect the problem and determine the answer. ● What key words does the question contain?● This question describes two gene loci (singular is gene locus). Each gene’s abbreviation uses two letters – bw for brown and hv for heavy veins. The genotypic ratio refers to the alleles in the DNA, and the phenotypic ratio refers to the physical phenotypes. Gather Content ● What do you already know about genetic linkage?● Genetic linkage refers to genes that lie close to each other on the chromosome. ● Because their loci are linked, they are not segregated by independent assortment. Consider Possibilities ● Consider the different answer options. Which can you rule out?● In the previous question, we determined the genotypic ratio to be 1:2:1. ● The phenotypes are a reflection of the genotypes, so we should expect phenotypes in the same 1:2:1 ratio. ● We can rule out the answer with a 1:1:1:1 ratio. ● The three genotypes produce three distinct phenotypes, so we can also rule out the answer with a 3:1 ratio. Choose Answer Version 1
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● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The cross will produce four categories of offspring in the F2: AA, AB, BA, and BB. But AB and BA are the same genotypically. So the genotypic ratio is 1:2:1 of AA: AB: BB. ● AA stands for bw hv+/ bw hv+, or brown eyes and thin wing veins. ● AB stands for bw hv+/ bw+ hv, or red eyes and thin wing veins (the dominant phenotypes). ● BB stands for bw+ hv/ bw+ hv, or red eyes and heavy wing veins. ● So we get 1 brown, thin: 2 red, thin: 1 red, heavy. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that you can treat the two tightly linked genes like a single gene? ● Did you write out the crosses and draw a Punnett square to determine the answer? ● Did you correctly match the genotypes to the phenotypes? 57.3) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses linked genes and testcrosses. ● What type of thinking is required?● You need to Analyze the information given, using logic, to dissect the problem and determine the answer. ● What key words does the question contain?● A testcross is a cross used to determine the genotype of one of the parents, by looking at the phenotypes that result when crossed to a tester strain. Gather Content ● What do you already know about linked genes and testcrosses?● Tightly linked genes segregate together, so you can treat them as a unit. ● Testcrosses typically use a double homozygous recessive strain, so that any dominant alleles in the other parent are revealed in the progeny. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Punnett squares are a useful way to determine both genotype and phenotype ratios. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Since testcrosses typically use a fully recessive homozygous strain, we should assume a homozygous bw hv is crossed to an F1 individual. ● The F1 are heterozygous bw hv+ / bw+ hv . Version 1
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● So the cross is bw hv+ / bw+ hv x bw hv / bw hv. ● Draw a Punnett square. The tester parent produces only bw hv gametes. ● Since the genes segregate together, the other parent produces just two kinds of gametes: bw hv+ and bw+ hv. ● This creates just two combinations of offspring in equal proportion: bw hv+ / bw hv and bw+ hv / bw hv. ● Their phenotypes are: brown eyes, thin wing veins and red eyes, heavy wing veins. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you remember the characteristics of a testcross? ● Did you recognize that the tester strain should be recessive for all genes? ● Did you use a Punnett square to help you determine the genotype ratios? ● Did you correctly match phenotypes to the genotypes? 58) Section Break 58.1) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the use of genetic maps and DNA markers. ● What type of thinking is required?● You need to Analyze the information given, using logic, to dissect the problem and determine the answer. ● What keywords does the question contain?● DNA markers are features in the DNA that can be analyzed and often differ between individuals. Forensics is the use of scientific methods to analyze crime data. Gather Content ● What do you already know about genetic maps and DNA markers?● Genetic maps provide information about the location and distances between genes. ● The human genome map was created using a few individuals to represent a generic human genome – but it does not encompass all of the human genetic diversity. ● DNA markers are features in the DNA that can differ between individuals, and be used to match or distinguish two samples of DNA. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Since we need to distinguish the DNA of the two brothers based on the fine details, the human genome map will not be useful. It would be far too expensive and complicated to produce a genome map for each of the suspects. ● Linkage data is also not useful – that only provides general Version 1
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distances between genes, and is not specific for individuals. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Consider the two remaining choices: markers on the Y chromosome, and SNPs. ● Since the two suspects are brothers, how different are their Y chromosomes? Not very! They will likely be the same since they presumably received their Y from the same father. (With the exception of some possible recombination in the pseudoautosomal region). ● Would single nucleotide polymorphisms (SNPs) be useful? Yes! They are exactly the kind of detailed fine feature that is likely to vary even between closely related individuals. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that you needed a source of information that reflected the fine structure differences in individual DNA? ● Did you recognize that their Y chromosomes would be the same? 58.2) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses mitochondrial inheritance. ● What type of thinking is required?● Although you may not have seen this example before, you know enough about the concept to Apply your knowledge and understanding to this unfamiliar situation. ● What key words does the question contain?● MItochondrial DNA is the DNA that encodes some of the proteins used by mitochondria (other mitochondrial proteins are encoded by regular nuclear DNA). The mitochondrial DNA is carried within the mitochondria. Gather Content ● What do you already know about mitochondrial DNA?● Mitochondrial DNA is carried within mitochondria, and mitochondria are inherited only from the mother – the sperm have too little cytoplasm to carry mitochondria. ● There is generally only one type of mitochondrial DNA in any individual. That is, all the mitochondria in an individual have the same mitochondrial DNA. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Mitochondrial genomes are small and easy to sequence – they have been sequenced. ● Mitochondrial DNA is inherited maternally, not paternally. ● Mitochondrial DNA is the same as nuclear DNA, and regular molecular biology techniques work fine. Version 1
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Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The correct answer is left – since the two men are brothers, they both inherited the same mitochondrial DNA from their mother. Thus, that information will not help distinguish the samples. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question required you to Apply your knowledge and understanding to this unfamiliar situation. ● Did you remember that mitochondrial DNA is maternally inherited? ● Did you recognize that brothers will have inherited the same mitochondrial DNA?
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Chapter 14 13e MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 1) Viruses that attack bacteria are called A) phages B) proviruses C) virulent D) lytic
2)
_________blank is the genetic material for all cellular organisms and some viruses. A) RNA B) DNA C) Protein D) Chromatin
3) Nucleotides have a phosphate group attached at the_________blank carbon atom of the sugar. A) 2' B) 3' C) 5' D) 1'
4)
Telomeres protect_________blank and are_________blank sequences of DNA.
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A) circular chromosomes from nucleases; random B) the ends of linear chromosomes from nucleases; specific short repeated C) circular chromosomes from nucleases; specific short repeated D) all chromosomes (prokaryotic and eukaryotic) from nucleases; random E) all chromosomes (prokaryotic and eukaryotic) from nucleases; specific short repeated
5) Watson and Crick developed a model of DNA in which the two strands twist into the shape of a_________blank. A) circle B) helix C) double helix D) double pleated sheet
6) Because the two strands of a DNA molecule are_________blank to each other, either one can be used as a template to reconstruct the other. A) identical B) antiparallel C) bound D) complementary
7)
DNA consists of two antiparallel strands of nucleotides held together by A) peptide bonds. B) covalentbonds. C) ionic bonds. D) hydrogen bonds.
8) The method of DNA replication, where each original strand is used as a template to build a new strand, is called the Version 1
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A) conservative method. B) semiconservative method. C) disruptive method. D) continuous method. E) replication and amplification method.
9)
Which enzyme adds new nucleotides to the end of a growing strand? A) Ligase B) Polymerase C) Gyrase D) Helicase E) Endonuclease
10)
Who originally discovered the process of bacterial transformation? A) Watson andCrick B) Chargaff C) Hershey andChase D) Griffith E) Meselson and Stahl
11) When a mixture of live nonvirulent bacteria and dead virulent bacteria was injected into mice, Griffith unexpectedly found that the injected mice died. He explained this result by suggesting that the nonvirulent bacteria are being A) activated. B) transformed. C) translated. D) transcribed. E) expressed.
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12) Avery and his coworkers showed that the agent responsible for changing nonvirulent bacteria into virulent bacteria was A) protein. B) polysaccharide. C) DNA. D) RNA. E) lipid.
13)
Which statement about the Hershey-Chase experiment is false? A) DNA was labeled with radioactive phosphorus. B) Protein was labeled with radioactive sulfur. C) Thevirus-infected bacteria contained radioactive phosphorus. D) The virus-infected bacteria contained radioactive sulfur.
14)
Based on their experiment with T2 bacteriophages, Hershey and Chase concluded that A) DNA replicationis semiconservative. B) the phagecoat contains the genetic material. C) DNA functionsas the genetic material. D) A always pairswith T and G always pairs with C. E) virulent bacteriacan transform nonvirulent bacteria.
15)
After attaching to a bacterial cell, a bacteriophage typically A) injects proteininto the cell. B) extracts proteinfrom the cell. C) injects DNA intothe cell. D) extracts DNA fromthe cell. E) transforms thecell into a virulent strain.
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16)
DNA primase A) creates a short RNAprimer that is complementary to an RNA template. B) creates a short DNAprimer that is complementary to an RNA template. C) creates a short DNAprimer that is complementary to a DNA template. D) creates a shortDNA template that is complementary to an RNA primer. E) creates a shortRNA primer that is complementary to a DNA template.
17) As the two strands of DNA are unraveled, which enzyme relieves the strain on the two strands? A) DNA polymerase B) DNA ligase C) DNA gyrase D) DNAendonuclease E) DNAexonuclease
18)
Which is not a component of nucleic acids? A) Organic nitrogenous base B) Pentose sugar C) Phosphate D) Sulfur
19) The chemical bond connecting one nucleotide with the next along one strand of a DNA molecule is called a
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A) glycosidicbond. B) hydrogen bond. C) phosphatebond. D) phosphodiester bond. E) peptide bond.
20)
Chargaff's rules for the pairing of nitrogen bases is A) A = C and G = T. B) A = T and G =C. C) A = G and C =T. D) A+T = G+C.
21) Information obtained by Franklin from X-ray crystallography on DNA suggested that it is shaped like a A) helix. B) ribbon. C) hollow cylinder. D) pleated sheet. E) icosahedron.
22)
In DNA, complementary nitrogen bases are held together by A) nitrogen bonds. B) hydrogen bonds. C) hydrophobic bonds. D) peptide bonds. E) phosphodiester bonds.
23)
The two strands of a DNA molecule contain nitrogen bases which are
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A) identical. B) parallel. C) complementary. D) proportionate. E) random.
24)
Replication of DNA is A) conservative. B) redundant. C) dispersive. D) semiconservative. E) semidispersive.
25)
During DNA replication, each new strand begins with a short A) amino acid primer. B) lipid primer. C) hydrophilic primer. D) DNA primer. E) RNA primer.
26) The lagging strand is replicated with a series of Okazaki fragments and that is why its synthesis is considered to be A) discontinuous. B) continuous. C) bidirectional. D) antiparallel. E) semiconservative.
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27) DNA replication always proceeds by adding new bases to the_________blank end of an existing strand. A) 1' B) 2' C) 3' D) 4' E) 5'
28)
Which of the following statements about DNA replication is false?
A) The two strands are separated. B) Each existingstrand is used as a template for making a new strand. C) Synthesis of both new strands is in the 5' to 3' direction. D) The newlysynthesized DNA is packaged into one nucleus, and the original DNA is packagedinto another nucleus.
29)
The double helix model of DNA structure was proposed by A) Watson and Crick. B) Griffith. C) Avery. D) Franklin. E) Chargaff.
30) Griffith, a British microbiologist, used bacteria and mice to demonstrate the process of transformation. During transformation,
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A) a bacterialchromosome produces an exact copy of itself. B) the nucleus of amouse cell repairs itself when damaged by bacterial infection. C) DNA from an infected mouse cell changes bacteria from a nonpathogenic to a pathogenic form. D) genetic material istransferred from one bacterial cell to another. E) a bacterial cell istransformed into a spore during unsuitable environmental conditions.
31)
In 1952, Hershey and Chase confirmed Avery's (1944) conclusion that A) proteins are therepositories for hereditary information. B) DNA is therepository for hereditary information. C) RNA is therepository for hereditary information. D) each DNA moleculeis composed of two strands that are twisted into a double helix. E) the replication ofDNA is semiconservative.
32) If 14% of the nucleotides from a DNA molecule contain the base T, what percent will contain the base G? A) 14% B) 18% C) 28% D) 36% E) 72%
33)
If a short sequence of DNA is 5' AATTGCCGT 3', its complement is A) 5' AAAACGCCA3'. B) 3' TTAACGGCT5'. C) 3' TTAACGGCA5'. D) 3' TTAAGCCGA5'. E) 5' TTAACGGCA 3'.
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34) After DNA replication is complete, each strand of the original molecule is bound to a new complementary strand. This process is known as A) disruptivereplication. B) conservativereplication. C) semiconservativereplication. D) dispersivereplication. E) stabilizingreplication.
35) The site where the two original DNA strands separate and active replication occurs is called the
A) replication fork. B) replisome. C) primosome. D) laggingstrand. E) sliding clamp subunit.
36)
The replisome has two main subcomponents. They are A) the replication folk and the sliding clamp subunit. B) the primosome and the sliding clamp subunit. C) the replication folk and the DNA pol III enzymes. D) the DNA pol III enzymes and the sliding clamp subunits. E) the primosome andthe DNA pol III enzymes.
37)
During replication, which enzyme unwinds the DNA double helix?
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A) DNA primase B) DNA polymerase I C) DNA helicase D) DNA gyrase E) DNA ligase
38)
What is the correct sequence for DNA replication in E. coli? A) Initiation, termination, elongation B) Initiation, elongation, termination C) Elongation, termination, initiation D) Elongation, initiation, termination
39)
Eukaryotic organisms speed up the process of DNA replication by A) shortening theinitiation phase. B) producing severalsliding clamp complexes which provide more binding sites for DNA
polIII. C) using DNA gyraseto unravel the double helix rather than DNA helicase. D) using multipleorigins of replication on each chromosome.
40) Endonucleases and exonucleases are enzymes that can remove nucleotides from a polynucleotide chain. An endonuclease removes nucleotides _______ while an exonuclease removes nucleotides_________blank. A) from the 5' end ofthe chain; from the 3' end of the chain B) from the 3' end ofthe chain; from the 5' end of the chain C) internally; fromthe ends of the chain D) from the ends ofthe chain; internally
41)
During DNA replication, DNA pol III synthesizes the lagging strand in segments, called
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A) replicationfragments. B) Chargaff's segments. C) repeating primers. D) replisomes. E) Okazaki fragments.
42) Who proposed that the structure of DNA is a double helix with two polynucleotide chains running in opposite directions and held together by hydrogen bonding between pairs of nitrogenous bases? A) Hershey and Chase B) Chargaff C) Franklin D) Watson and Crick E) Meselson and Stahl
43)
Who demonstrated that phage genetic material is DNA and not protein? A) Hershey and Chase B) Chargaff C) Franklin D) Watson and Crick E) Avery, MacLeod, and McCarty
44) Who provided X-ray diffraction photographs of purified DNA fibers that suggested a helical structure with a consistent diameter of about 2 nm and a complete helical turn every 3.4 nm? A) Hershey and Chase B) Chargaff C) Franklin D) Watson and Crick
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45)
Who proposed that in any DNA molecule, A = T and G = C? A) Hershey and Chase B) Chargaff C) Franklin D) Watson and Crick
46)
In Griffith's experiments,
A) mice infected withlive nonvirulent bacteria developed pneumonia and died. B) nonvirulentbacteria transformed the virulent bacteria into a nonvirulent variety. C) mice infected withheat-killed virulent bacteria and live nonvirulent bacteria developedpneumonia and died. D) mice infected withheat-killed virulent bacteria and heat-killed nonvirulentbacteria developed pneumonia and died.
47) Avery, MacLeod, and McCarty's experiments revealed that the transforming principle had all of the following properties except A) its activity was destroyed by treatment with proteases. B) its activity was unaffected by RNA-digesting enzymes. C) its activity was unaffected by lipid extraction. D) its activity was destroyed by treatment with DNA endonucleases.
48) If we think of the DNA double helix as a twisted ladder, what makes up the rungs or steps of the ladder?
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A) Phosphate groups only B) Alternating phosphate groups and sugars C) Sugars only D) Purines and pyrimidines E) Phosphate groups and bases
49) Deoxyribose has a carbon atom that is not part of the pentose ring. In a nucleotide, what is attached to this carbon? A) A nitrogenous base B) A phosphate group C) Three hydrogen atoms D) One hydrogen atom
50)
Which of the following DNA sequences is complementary to 5' ATGGTCAGT 3'? A) 5' ATGGTCAGT 3' B) 5' TGACTGGTA 3' C) 5' TACCAGTCA 3' D) 5' ACTGACCAT 3'
51) that
In DNA, a purine must always pair with a pyrimidine and vice versa in order to ensure
A) the distancebetween the two phosphodiester backbones remains constant. B) the two strandsare antiparallel. C) the distancebetween one base pair and the next remains constant. D) each base pair is held together by three hydrogen bonds.
52) gap?
During DNA replication, which enzyme removes the RNA primers and then fills in the
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A) DNA pol I B) DNA primase C) DNA pol III D) DNA ligase
53) If a mutation prevented synthesis of the beta subunit of DNA pol III, which would be most affected? A) DNA unwinding B) Formation of RNA primers C) Formation of the replication fork D) Processivity E) Removal of RNA primers
54)
Why does DNA pol I carry the number one? A) It was the firstpolymerase isolated from E. coli. B) It is the firstpolymerase to be activated during DNA replication. C) It is the onlypolymerase that has both 3' to 5' and 5' to 3' exonuclease activity. D) It is the smallestpolymerase.
55) You are asked to give a classroom demonstration of DNA supercoiling. To do so, you take two different colored pieces of rubber tubing, twist them very tightly and excessively around each other and join the ends of the tubing appropriately. Next, you relieve the supercoiling by breaking one strand and unwinding it. In this demonstration, the breaking and unwinding to relieve the supercoiling simulates the action of A) exonucleases. B) polymerases. C) ligases. D) topoisomerases. E) primases.
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56)
In which cells would you expect to find the highest level of telomerase? A) Muscle cells B) Adipose tissue cells C) Neurons D) Cells that replenish the lining of the gut
57) You are asked to participate in a clinical trial for a new drug that can activate telomerase. Which of the following is a likely risk of such a drug? A) Decreased capacity for tissue repair B) Increased vulnerability to cancer C) Premature aging D) Decreased telomere length
58) When planning a long week of sunbathing on the beach, which type of DNA damage should sunbathers be aware of before hitting the beach? A) Photolyase-induced mutations B) Decreased telomere length C) Thymine dimers D) Activation of uvr A, B, and C genes
59) Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder. Patients with XP exhibit a cellular hypersensitivity to ultraviolet (UV) radiation, a high incidence of skin cancer and premature aging. Based on these clinical characteristics, what is the most likely cause for this disease? A) Defects in DNA repair B) Defects in DNA replication C) Lack of telomerase activity D) Shortened telomeres
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60) If a mutation produced helicase that was unable to hydrolyze ATP, DNA replication would be A) stopped. B) speeded up. C) unaffected. D) more prone to errors.
61) Suppose a new species of bacterium is discovered. It contains a form of DNA pol III that can add new nucleotides to either the 5' end or the 3' end of an existing strand. All other properties of the enzyme remain unchanged. How would DNA replication in these bacteria differ from normal replication? A) Both new strands could be synthesized continuously like the leading strand. B) The same polymerase molecule could synthesize both strands at the same time. C) Helicase would no longer be required for replication. D) DNA gyrase would no longer be required for replication.
62) If 16% of the nucleotides in one strand of a DNA molecule contain the base G, what percent of the nucleotides on the complementary strand will also contain the base G? A) 16% B) 8% C) 34% D) 32% E) It is impossible to determine from the information given.
63) You decide to repeat the Meselson-Stahl experiment, except this time you plan to grow the E. coli cells on light 14N medium for many generations and then transfer them to heavy 15N medium and allow them to grow for 2 additional generations (2 rounds of DNA replication). If the conservative model of DNA replication was correct, what is the expected distribution of DNA in the density gradient after two rounds of replication?
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A) One band of intermediate density. B) One band of light density. C) One band of heavy density. D) One band of light density and one band of heavy density. E) One band of light density and one band of intermediate density.
64) You decide to repeat the Meselson-Stahl experiment, except this time you plan to grow theE. coli cells on light14N medium for many generations and then transfer them to heavy15N medium and allow them to grow for 2 additional generations (2 rounds of DNA replication). If the semiconservative model of DNA replication is correct, what is the expected distribution of DNA in the density gradient after two rounds of replication? A) One band of intermediate density. B) One band of intermediate density and one band of light density. C) One band of intermediate density and one band of heavy density. D) One band of heavy density and one band of light density. E) One band of heavy density.
65) Genetic analysis indicates that an unknown organism contains a gene that codes for a defective form of telomerase. Based on this information alone, you can conclude that this organism A) isprokaryotic. B) is eukaryotic. C) has unusually longtelomeres. D) has an increasedrisk of developing cancer.
66) An organism has been found to contain a defective form of photolyase. What function might be impaired in this organism?
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A) Lengthening of the tips of chromosomes B) Repair of DNA damage caused by UV light C) Stabilization of single-stranded DNA during DNA replication D) Recognition of damaged DNA by the UvrABC complex
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Answer Key Test name: Chap 14_13e_Raven 1) A 2) B 3) C 4) B 5) C 6) D
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Clarify Question • What is the key concept addressed by the question? o This question addresses DNA structure. • What type of thinking is required? o You will need to Apply your knowledge and understanding to this unfamiliar situation. • What key words does the question contain? o DNA strands refers to the configuration of genetic material in prokaryotic and eukaryotic organisms. Gather Content • What do you already know about the structure of DNA? o A single molecule of DNA consists of two paired DNA strands that are connected via hydrogen bonds between the nitrogenous bases on each strand. o Based on the physical structure of the nitrogenous bases, A pairs with T, and G pairs with C to keep the diameter of the entire double helix constant. Consider Possibilities • What other information is related to the question? Which information is most useful? o We have learned that the DNA strands are antiparallel. That means that one strand runs 5’ to 3’, and the other runs 3’ to 5’. o We also know that the pattern of base-pairing is complementary in that there each pair consists of one pyrimidine (C or T) and one purine (G or A). Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o This question is asking not just about the features of DNA, but how those features relate to DNA replication. o Specifically, which feature confers the ability of each strand to serve as a template for replication of a new strand? o DNA strands are not identical as the bases are complementary between strands. o Two strands of DNA are bound to one another via hydrogen bonds, but that does not play in role in the assignment of bases during replication. o The two strands of a DNA molecule do run antiparellel to one another, but again that does not affect the base pairing during replication. o The fact that the two strands of DNA are complementary to one another does mean that if either is replicated, the new daughter strand will match up appropriately based on the strict pairing of A to T and C to G. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question required you to Apply you knowledge to the question determine the answer. o Did you remember the key characteristics of DNA molecules? o Did you recognize that even though some of the answers are features of DNA, only one can account for proper base pairing during replication 7) D 8) B Version 1
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9) B 10) D 11) B 12) C 13) D 14) C 15) C 16) E 17) C 18) D 19) D 20) B 21) A 22) B 23) C 24) D 25) E 26) A 27) C 28) D 29) A 30) D 31) B 32) D
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Clarify Question • What is the key concept addressed by the question? o This question addresses base-pairing. • What type of thinking is required? o You need to Analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain? o Nucleotides are the modular units of DNA composed of a phosphate group, a sugar and a nitrogenous base. The four bases, adenine, thymine, guanine and cytosine are abbreviated A, T, G and C, respectively. Gather Content • What do you already know about base-pairing? o Base-pairing is the interaction that connects the two strands of a DNA molecule. o A pairs with T, and G pairs with C. Consider Possibilities • What other information is related to the question? Which information is most useful? o Since T pairs with A, and G pairs with C, the % of T nucleotides does not equate to the number of G nucleotides. o But, it does equate to the number of A nucleotides. For every T in the DNA, there will be an A. o So we know there is 14% T and 14% A. o We also know there are just four kinds of nucelotides that make up the DNA. Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Now we can solve this as a math problem. o The four types of nucleotides add up to 100%. A + T + C + G = 100% o A = T = 14% o Since G pairs with C, they also have the save value. G = C o 14% + 14% + C + G = 100% o 28% + 2G = 100% o 2G = 72% o 72%/2 = G = 36% Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. o Did you remember that A pairs with T, and G pairs with C? o Did you recognize that since they pair, the percent of T is equal to the percent of A? o Did you recognize that all four nucleotides must add up to 100%? 33) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses base-pairing. • What type of thinking is required? o Although you may not have seen this example before, you know enough about the concept to Apply your knowledge and understanding to this unfamiliar situation. • What key words does the question contain? o A DNA sequence has a direction, which is referred to as 5’ to 3’, or 3’ to 5’. These refer to the carbons on the sugar molecule which connect between the phosphates in the backbone. The complement of a DNA sequence is the sequence of its opposite strand. Gather Content • What do you already know about base-pairing? o Base-pairing is the interaction that connects the two strands of a DNA molecule. o A pairs with T, and G pairs with C. Consider Possibilities • Consider the different answer options. Which can you rule out? o We have learned that the DNA strands are antiparallel. That means that one strand runs 5’ to 3’, and the other runs 3’ to 5’. o One of the answers appears to base-pair properly, but would not be antiparallel, so you can rule that out. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Starting at the 5’ of the original sequence, we can deduce the Version 1
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complementary sequence. o The original strand starts with 5’, so it’s complement begins at the 3’ end. o The original strand starts out 5’ AATT. o We know that A base pairs with T, and vice versa, so its complement is 3’ TTAA. o We know that G base pairs with C, and vice versa, so continuing on the complete complement is: 3' TTAACGGCA 5'. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question required you to Apply your knowledge and understanding to this unfamiliar situation. o Did you remember that A binds with T, and G binds with C? o Did you recognize that the two DNA strands are antiparallel, so the answer should begin 3’ TTAA? o Note: It is permissible to write a DNA strand in either direction. So an acceptable answer could also have been 5’ ACGGCAATT 3’. How is this different from the wrong answer 5’ TTAACGGCA 3’? 34) C 35) A 36) E 37) C 38) B 39) D 40) C 41) E 42) D Version 1
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43) A 44) C 45) B 46) C 47) A 48) D 49) B 50) D
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Clarify Question • What is the key concept addressed by the question? o This question addresses base-pairing. • What type of thinking is required? o Although you may not have seen this example before, you know enough about the concept to Apply your knowledge and understanding to this unfamiliar situation. • What key words does the question contain? o A DNA sequence has a direction, which is referred to as 5’ to 3’, or 3’ to 5’. These refer to the carbons on the sugar molecule which connect between the phosphates in the backbone. The complement of a DNA sequence is the sequence of its opposite strand. Gather Content • What do you already know about base-pairing? o Base-pairing is the interaction that connects the two strands of a DNA molecule. o A pairs with T, and G pairs with C. Consider Possibilities • What other information is related to the question? Which information is most useful? o We have learned that the DNA strands are antiparallel. That means that one strand runs 5’ to 3’, and the other runs 3’ to 5’. o We can write the DNA either way, as long as we clearly note the direction. So 3’ ATCG 5’ is the same exact sequence as 5’ GCTA 3’. o Note that all the answer options are written to begin with 5’, just like the original sequence. So to match them, we should read from the 3’ end. Version 1
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Starting at the 5’ of the original sequence, we can deduce the complementary sequence. o The original strand starts with 5’, so it’s complement begins at the 3’ end. o The original strand is 5' ATGGTCAGT 3'. o We know that A base pairs with T, and vice versa, and G base pairs with C, and vice versa. o So the complement of the original strand is 3’ TACCAGTCA 5’. o BUT, note that all the answer options are written from 5’ to 3’. So we need to flip our notation like so: 5’ ACTGACCAT 3’. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. o Did you remember that A binds with T, and G binds with C? o Did you recognize that the two DNA strands are antiparallel? o Did you recognize that all the answer options were written from 5’ to 3’? 51) A 52) A 53) D
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Clarify Question • What is the key concept addressed by the question? o This question addresses the function of DNA polymerase. What type of thinking is required? o You need to Analyze the information given, using logic, to dissect the problem and determine the answer. What key words does the question contain? o DNA pol III is the abbreviation for DNA Polymerase III. One particular protein subunit is the beta (β) subunit. Gather Content What do you already know about DNA polymerase? o DNA polymerase III is responsible for the bulk of DNA synthesis in E. coli. o The beta subunit is known as a “sliding clamp”. It forms a ring that can slide along the DNA. Consider Possibilities Consider the different answer options. Which can you rule out? o DNA pol III is a DNA polymerase – it synthesizes DNA, not RNA. So it is unrelated to the formation of RNA primers. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The beta subunit forms a ring that slides along the DNA. Its role is to keep the polymerase attached to the DNA. As long as the polymerase stays on the DNA, it can continue to synthesize DNA on the leading Version 1
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strand. o The continuous synthesis of DNA is called processivity. Thus, if the beta subunit sliding clamp was missing, the polymerase would fall off the DNA and lack processivity. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. o Did you remember that the beta subunit is shaped like a ring – a sliding clamp? o Did you recognize that if the beta subunit was missing, the polymerase would fall off the DNA more often? o Did you remember that the quality of continuing to synthesize DNA is called processivity? 54) A 55) D
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Clarify Question • What is the key concept addressed by the question? o This question addresses supercoiling and the function of different enzymes. • What type of thinking is required? o Although you may not have seen this example before, you know enough about the concept to Apply your knowledge and understanding to this unfamiliar situation. • What key words does the question contain? o Supercoiling is the twisting that can occur in DNA, particularly after helicase has unwound part of the double-stranded portion for replication. Gather Content • What do you already know about supercoiling? o DNA can become highly twisted, or supercoiled. These twisted loops interfere with replication, and the torsion is relieved by enzymes. Consider Possibilities • What other information is related to the question? Which information is most useful? o Look at the answer options. Each is the name of an enzyme. o An enzyme name often ends in “-ase”. The beginning of the name is usually a prefix that hints at the enzyme's job. The name can help us remember what the enzyme does. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o You are being asked to name the type of enzyme that relieves supercoiling by cutting, unwinding, and reconnecting the DNA. o You may remember that DNA gyrase does this, but that option isn’t here. What is the name of the class of enzymes to which DNA gyrase belongs? o If you don’t remember the name of the enzyme, go through each of the options and figure out their names: o Exonuclease: An enzyme that cuts nucleotides (“nucle”) from the outside (the end, “exo”). o Ligase: An enzyme that ties (“ligates”) DNA together. o Polymerase: An enzyme that makes “polymers”, or strings of multiple units. o Primase: An enzyme that “primes”, or starts the process of synthesis by making a primer. o Topoisomerase: An enzyme that changes the shape (“topology”) of the DNA into another version (“isomer”). That’s it! Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question required you to Apply your knowledge and understanding to this unfamiliar situation. o Did you remember that topoisomerases are the enzymes that relieve supercoiling? o If not, did you try analyzing the enzyme names to infer their functions? 56) D
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Clarify Question • What is the key concept addressed by the question? o This question addresses the function of telomerase. What type of thinking is required? o This answer requires you to weigh and judge evidence – to Evaluate – and choose the best of the possible answers. What key words does the question contain? o Telomerase is an enzyme that creates telomeres on the ends of DNA. Gather Content • What do you already know about telomeres and telomerase? o Telomeres are short repeated sequences of DNA, which are found at the tips of each chromosome. o They are made by an enzyme called telomerase, which uses an internal RNA as a template and not the DNA itself. o Telomeres serve to cap off the end of the DNA, protecting it and preventing the molecule from getting shorter in every replication (due to the usual need for a primer). Consider Possibilities • What other information is related to the question? Which information is most useful? o A gradual shortening of the ends of chromosomes occurs in the absence of telomerase activity. This is part of the reason cells senesce, or eventually age and die. o During embryonic and childhood development in humans, telomerase activity is high, but it is low in most somatic cells of the adult. o The exceptions are cells that must divide as part of their function, such as lymphocytes. Version 1
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o So what cells must divide multiple times during the life of an adult? o Not neurons, which do not divide. Not muscle cells. Not fat cells (adipose tissue). o But cells that replenish the gut lining do divide multiple times, and therefore you could expect high levels of telomerase. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question required you to weigh and judge evidence – to Evaluate – and choose the best of the possible answers. o Did you remember that telomerase acts to build telomeres on newly replicated DNA? o Did you recognize that you should pick the cell type that undergoes rounds of cell division? 57) B
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Clarify Question • What is the key concept addressed by the question? o This question addresses the function of telomerase. What type of thinking is required? o This answer requires you to weigh and judge evidence – to Evaluate – and choose the best of the possible answers. What key words does the question contain? o A clinical trial is a test of a new drug using human patients. Telomerase is the enzyme that builds telomeres on the ends of DNA. Gather Content • What do you already know about telomeres and telomerase? o Telomeres are short repeated sequences of DNA, which are found at the tips of each chromosome. o They are made by an enzyme called telomerase, which uses an internal RNA as a template and not the DNA itself. o Telomeres serve to cap off the end of the DNA, protecting it and preventing the molecule from getting shorter in every replication (due to the usual need for a primer). Consider Possibilities • What other information is related to the question? Which information is most useful? o A gradual shortening of the ends of chromosomes occurs in the absence of telomerase activity. This is part of the reason cells senesce, or eventually age and die. o During embryonic and childhood development in humans, telomerase activity is high, but it is low in most somatic cells of the adult. o The exceptions are cells that must divide as part of their function, Version 1
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such as lymphocytes. Consider Possibilities • Consider the different answer options. Which can you rule out? o Having higher telomerase activity would give cells longer telomeres, allowing them to continue to divide. o So you can rule out the answer “decreased telomere length”. o Longer telomeres is likely to increase, not decrease, capacity for tissue repair, so you can rule out that answer. o Longer telomeres is also likely to decrease aging, so you can rule out that answer. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The remaining answer is “increased vulnerability to cancer”. Does this make sense? o Cancer cells divide multiple times. Repeated division gradually shortens and loses the telomeres and degrades the DNA ends. o But with telomerase present, telomeres can be continually reformed. o This removes one of the hurdles for cancer cells to proliferate. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question required you to weigh and judge evidence – to Evaluate – and choose the best of the possible answers. o Did you remember that telomerase adds telomeres to the ends of Version 1
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DNA? o Did you recognize that cancer cells need to divide multiple times? 58) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses light-induced DNA damage. What type of thinking is required? o Although you may not have seen this example before, you know enough about the concept to Apply your knowledge and understanding to this unfamiliar situation. • What key words does the question contain? o DNA damage refers to a defect in the structure of DNA, often caused by chemicals (mutagens) or UV light. Gather Content • What do you already know about light-induced DNA damage? o Sunlight includes UV radiation which can be damaging to DNA. o UV light damages DNA by causing formation of thymine dimers. o When two thymines are adjacent, they can become bound together, distorting the helix of the DNA. This can lead to a permanent mutation after DNA replication. Consider Possibilities • Consider the different answer options. Which can you rule out? o Two of the answer options refer not to DNA damage, but to DNA repair mechanisms: photolyase and the uvr genes act to repair DNA. We are looking for an example of UV-light induced DNA damage. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o Decreased telomere length would be damaging to DNA, but this is not a common result from UV-light. o Instead, formation of thymine dimers is the most common photoproduct of DNA damage. o It activates the photorepair pathway, involving recognition of the thymine dimer by photolyase. (So, photolyase is a “good guy”!) Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question required you to Apply your knowledge and understanding to this unfamiliar situation. o Did you remember that thymine dimers are a common result of DNA damage? o Did you recognize that photolyase and the uvr genes help repair DNA? o Next time you plan a day in the sun, how can you reduce your risk of thymine dimer formation? 59) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses DNA replication and repair. • What type of thinking is required? o This answer requires you to weigh and judge evidence – to Evaluate – and choose the best of the possible answers. • What key words does the question contain? o Xeroderma pigmentosum is a genetic disease. For this question, you simply need to understand its symptoms as described: sensitivity to UV, skin cancer, and aging. Gather Content • What do you already know about DNA replication and repair? o DNA replication is the process that makes more DNA before cell division. o Along with replication, the enzyme telomerase adds telomeres to the ends of the DNA to protect them. o DNA repair is the process of recognizing and fixing damage to the DNA. o The damage can come from chemicals or from the UV radiation in sunlight. Consider Possibilities • What other information is related to the question? Which information is most useful? o We are told that XP patients have three types of symptoms: sensitivity to UV, skin cancer, and premature aging. What ties together these three things? o You might consider a connection relating to telomeres. After all, an Version 1
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increase in telomerase activity is seen in cancer cells, and telomerase is thought to counteract aging. o But, the main problem from UV light is that it damages DNA by creating thymine dimers, not damaging telomeres. So that doesn’t fit. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o What does it mean exactly to be hypersensitive to UV light? It means that UV is even more damaging than usual. o First consider what UV does to a healthy individual. The UV causes damage to the structure of DNA, which is recognized and repaired by enzymes. o If the DNA damage is not repaired, cancer can develop. DNA damage also contributes to aging, and DNA repair can slow the effects of aging. o So imagine an individual with a nonfunctional DNA repair process, due to a missing enzyme. UV-induced DNA damage would go unrepaired, leading to a high rate of skin cancer and increased effects of aging. This describes Xeroderma pigmentosum. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question required you to weigh and judge evidence – to Evaluate – and choose the best of the possible answers. o Did you recognize that sensitivity to UV, skin cancer, and aging all related to DNA repair? o Xeroderma pigmentosum cannot be cured. But with special Version 1
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precautions, individuals can live into middle age. What precautions would you recommend to an XP patient? 60) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses the function of helicase. • What type of thinking is required? o You need to Analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain? o Helicase is the enzyme that unwinds DNA during DNA replication (the process of making new copies of DNA). Hydrolyzing ATP means breaking ATP down into ADP and a phosphate. Hydrolysis means breaking (lysis) using water (hydro). Gather Content • What do you already know about the function of helicase? o Helicase unwinds the double helix of DNA at the replication fork. The strands have to be separated in order to be copied. o Helicase uses ATP as a source of energy to separate the strands, which are more stable bound together. Consider Possibilities • Consider the different answer options. Which can you rule out? o We know that helicase requires ATP. So a mutation that prevented hydrolysis of ATP would mean helicase couldn’t get energy to do its job. o We also know that helicase is an important part of the replication machinery, so having it “broken” would definitely interfere with DNA replication. o So we can rule out the answer that says DNA replication would be unaffected. Version 1
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o So if helicase was “broken”, what would result? The DNA would stay double-stranded and wound together. o If DNA stayed double stranded, the whole replication fork would stop and could not continue. o It would not speed up or even continue with errors, because the DNA polymerase would not have access to the template strand for copying. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. o Did you remember that helicase acts to unwind the double-stranded DNA? o Did you recognize that helicase must hydrolyze ATP to have energy to drive the unwinding? 61) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses DNA replication. • What type of thinking is required? o You need to Analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain? o DNA Pol III is the polymerase that synthesizes DNA during replication. 5’ and 3’ are directions of the DNA backbone. Gather Content • What do you already know about DNA replication? o Normally, DNA replication proceeds differently on each strand, due to the directionality of the DNA pol III enzyme. o On the leading strand, DNA pol III can add nucleotides continuously after a single primer starts the process. o On the lagging strand, DNA pol III has to add DNA in short segments called Okazaki fragments, each proceeding from a primer. Consider Possibilities • What other information is related to the question? Which information is most useful? o The question suggests that the hypothetical enzyme is different from normal DNA pol III – it can add nucleotides in either direction. o What would this mean for the leading strand? Not much – synthesis on the leading strand can already go quickly and continuously, following the replication fork. o So this would most affect the lagging strand. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o What would occur on the lagging strand in this scenario? After primase adds the first primer, the mutant DNA pol III could add nucleotides normally in the 5’ to 3’ direction. But it could ALSO add nucleotides starting from the other side of the RNA primer – in the 3’ to 5’ direction. o Thus, in this scenario, even the “lagging strand” could proceed with a single, continuous activity of the DNA polymerase following the unwinding of the replication fork. So it would be continuous, just like the leading strand. o Helicase and gyrase would still be required – the replcation fork would still need the DNA to be separated, unwound, and have the supercoiling relieved. o Although each strand of DNA could be synthesized continuously, they would still require separate enzymes to do so. Remember, even in a circular bacterial genome, the two strands are two separate strands – their backbones do not connect. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that lagging strand synthesis is normally discontinuous because of the directionality of DNA pol III? o Did you realize that the functions of helicase and gyrase would not be changed? Version 1
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62) E
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Clarify Question • What is the key concept addressed by the question? o This question addresses base pairing in DNA. • What type of thinking is required? o You need to Analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain? o The nucleotides in DNA are the modular units that contain bases adenine, thymine, cytosine, and guanine, known as A, T, C, and G, respectively. The complementary strand of DNA is the other strand of the double helix that must base pair with the first strand. Gather Content • What do you already know about base pairing in DNA? o Base pairing in DNA follows the rules: A binds with T, and C binds with G. o One strand of the double helix must bind its complementary strand according to these rules. Consider Possibilities • What other information is related to the question? Which information is most useful? o There are only four bases in DNA, so the percentage of those four must add up to 100% of the DNA bases. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o What can we infer from the information that one strand contains 16% G? o We know that G binds with C on the opposite strand, so we can infer that the complement contains 16% C. o What else can we infer? Not much! o Try the approach of imagining examples and testing each one. o What about a sequence like ATGCGC? In this case, there would be an equal number of Gs in each strand, because the top strand has an equal number of Gs and Cs. But does that have to be the case? o What about the sequence ATGGGG? Now, the top strand has only Gs, and the bottom strand has only Cs! o We know that in the top strand, (A + T + C) + 16% = 100%, and in the bottom strand (A + T + G) + 16% = 100%. But without further information, there is no way to know how much the remaining three bases are contributing to the DNA. The answer is impossible to determine. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. o Did you remember that G binds with C? o Did you recognize that Gs and Cs don’t have to equate on the same strand? o Did you test examples of your own to analyze possibilites? o Could a piece of DNA be all Gs on one strand, and all Cs on another? 63) D
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Clarify Question • What is the key concept addressed by the question? o This question addresses the Meselson-Stahl experiment. • What type of thinking is required? o You need to Analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain? o The Meselson-Stahl experiment was a classic experiment that demonstrated that DNA replication is semi-conservative. The medium is the nutrient broth the cells are grown in – when grown with 14N, the DNA is light, when grown with 15N, the DNA is heavy. Gather Content • What do you already know about the Meselson-Stahl experiment? o The Meselson-Stahl experiment was a clever, classic experiment that tested whether DNA replication was conservative, semiconservative, or dispersive. o The bands on the density gradient indicated how much of the 15N was incorporated into the new strands of DNA. Heavy bands were all 15N, light bands were all 14N, and intermediate bands had a mixture. Consider Possibilities • What other information is related to the question? Which information is most useful? o The results of the real experiment showed that in each round of replication, the new DNA has one old strand and one newly-synthesized strand. This supported the semiconservative model. o The template strand was “conserved”, but each new DNA double helix contained one fresh strand. Version 1
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o A diagram can help to answer this question. You can use two colors to indicate light 14N strands and heavy 15N strands. o Remember, the question supposes that replication was conservative – that would mean that one double helix is all old DNA, the other is all new. o We start out with all light DNA. In the first round, there would result two new pieces of DNA – one all new/heavy, the other all old/light. o In the second round, there would result two new/heavy, and two old/light. o In the conservative model, no hybrid new/old DNAs are formed. So the gradient bands would be light and heavy. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. o Did you remember the meaning of the conservative model? o Did you recognize what types of DNA would result from this experiment? o Did you try drawing a diagram to help answer the question? 64) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses the Meselson-Stahl experiment. • What type of thinking is required? oYou need to Analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain? o The Meselson-Stahl experiment was a classic experiment that demonstrated that DNA replication is semiconservative. The medium is the nutrient broth the cells are grown in – when grown with 14N, the DNA is light, when grown with 15N, the DNA is heavy. Gather Content • What do you already know about the Meselson-Stahl experiment? o The Meselson-Stahl experiment was a clever, classic experiment that tested whether DNA replication was conservative, semiconservative, or dispersive. o The bands on the density gradient indicated how much of the 15N was incorporated into the new strands of DNA. Heavy bands were all 15N, light bands were all 14N, and intermediate bands had a mixture. Consider Possibilities • What other information is related to the question? Which information is most useful? o The results of the real experiment showed that in each round of replication, the new DNA has one old strand and one newly-synthesized strand. This supported the semiconservative model. o The template strand was “conserved”, but each new DNA double helix contained one fresh strand. Version 1
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o A diagram can help to answer this question. You can use two colors to indicate light 14N strands and heavy 15N strands. o Remember, the question asks you to assume that replication is semiconservative – that would mean that each new double helix has one strand of new DNA, and one strand of old DNA. o We start out with all light DNA. In the first round, there would result two new pieces of DNA – each a hybrid of heavy and light. o In the second round, there would be two hybrid heavy/light molecules, plus two all heavy molecules. o Thus, a heavy band and an intermediate density band. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question required you to Analyze the information given, using logic, to dissect the problem and determine the answer. o Did you remember the meaning of the semiconservative model? o Did you recognize what types of DNA would result from this experiment? o Did you try drawing a diagram to help answer the question? 65) B
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Clarify Question • What is the key concept addressed by the question? o This question addresses the function of telomerase. • What type of thinking is required? o Although you may not have seen this example before, you know enough about the concept to Apply your knowledge and understanding to this unfamiliar situation. • What key words does the question contain? o Telomerase is the enzyme that adds telomeres to the ends of chromosomes. Gather Content • What do you already know about telomerase? o Telomerase addresses the problem presented by linear chromosomes during DNA replication. If not for telomeres, the chromosome ends would gradually get shorter and shorter with each replication event. Consider Possibilities • Consider the different answer options. Which can you rule out? o Does a defective telomerase suggest long telomeres? No, the opposite. Telomerase is necessary to add the telomeres. o Does a defective telomerase suggest a risk of cancer? Well, without telomeres, DNA can become damaged. But in fact cancer cells upregulate telomerase, so that the cells can survive multiple rounds of replication and division. So no, defective telomerase would not increase cancer. o Does a defective telomerase indicate that the organism is prokaryotic? No, because prokaryotes do not have telomerase at all, and never did. They generally have circular chromosomes so they have no need for Version 1
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telomerase. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Does a defective telomerase indicate that the organism is eukaryotic? Well, yes! Only eukaryotes have telomerase. They will likely be hampered without a functional gene, but the presence of the gene does suggest that they must be a eukaryote. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question required you to Apply your knowledge and understanding to this unfamiliar situation. o Did you remember that telomerase is necessary to add telomeres? o Did you recognize that only eukaryotes have telomerase? 66) B
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Clarify Question • What is the key concept addressed by the question? o This question addresses the function of photolyase. • What type of thinking is required? o Although you may not have seen this example before, you know enough about the concept to Apply your knowledge and understanding to this unfamiliar situation. • What key words does the question contain? o Photolyase is an enzyme in the photorepair pathway. Gather Content • What do you already know about photolyase? o Photolyase recognizes thymine dimers – the main damage caused by UV light – and repairs them. Consider Possibilities • Consider the different answer options. Which can you rule out? o Does photolyase lengthen the tips of chromosomes? No, that’s telomerase. o Does photolyase stabilize single-stranded DNA? No, those are the SSBs, single-stranded DNA binding proteins. o Does photolyase recognize damaged DNA with the UvrABC complex? Close, but that is a different DNA repair pathway. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Without photolyase, the organism would be less equipped to repair UV-induced DNA damage. Version 1
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question required you to Apply your knowledge and understanding to this unfamiliar situation. o Did you remember that photolyase recognizes and fixes the DNA damage caused by UV light?
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Chapter 15 13e MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 1) DNA affects the traits of an organism by providing the instructions for synthesizing_________blank. A) proteins B) nucleotides C) codons D) amino acids
2)
Gene expression involves two phases,_________blank and translation. A) replication B) transcription C) initiation D) condensation
3) Messenger RNA molecules contain information that is used to synthesize_________blank. A) nucleotides B) amino acids C) polypeptides D) fatty acids
4) To begin transcription, RNA polymerase must bind to a segment of DNA called the_________blank.
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A) initiationsite B) primer C) inducer D) promoter E) transcription bubble
5)
The strand of DNA that is not transcribed is called the_________blank strand. A) coding B) noncoding C) template D) complementary
6) During_________blank, a ribosome assembles a polypeptide whose amino acid sequence is specified by the nucleotide sequence in a molecule of mRNA. A) transcription B) translation C) replication D) posttranscriptional modification
7)
The sequence of nucleotides in a DNA molecule is called the_________blank code. A) protein B) ribosomal C) translation D) genetic E) amino acid
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8) Crick, Brenner, and their colleagues proposed that the genetic code consists of a series of blocks of information, called_________blank, each corresponding to one amino acid in an encoded protein. A) alleles B) codons C) genes D) polypeptides
9)
Gene_________blank refers to the combined processes of transcription and translation. A) expression B) replication C) modification D) regulation
10) During transcription of mRNA in eukaryotes, some sequences are cut out of the primary transcript and the remaining sequences are joined together. This processing of mRNA is called_________blank. A) termination B) translation C) splicing D) capping E) elongation
11) Most eukaryotic genes contain noncoding sequences called_________blank that are interspersed with the coding sequences.
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A) introns B) exons C) codons D) spacers E) spliceosomes
12) To remove noncoding sequences in the pre-mRNA of eukaryotes, multiple snRNPs combine with proteins to form a larger complex called the_________blank. A) 5' cap B) introsome C) ribosome D) spliceosome E) 3' poly-A tail
13) The connection that exists between genes and hereditary traits is based on using the information encoded in genes to synthesize A) codons. B) nucleotides. C) proteins. D) histones. E) complementary bases.
14)
Both DNA and RNA are made up of building blocks known as A) nucleotides. B) nucleicacids. C) amino acids. D) genes. E) codons.
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15)
The "one-gene/one-enzyme" hypothesis was proposed by A) Watson and Crick. B) Griffith. C) Garrod. D) Franklin. E) Beadle and Tatum.
16) The polypeptide-making organelles, which consist of protein combined with RNA, are called A) ribosomes. B) Golgi bodies. C) lysosomes. D) centrosomes. E) mitochondria.
17)
During translation, amino acids are carried to the ribosome by A) mRNA. B) tRNA. C) snRNA. D) rRNA. E) miRNA.
18) During_________blank, RNA polymerase synthesizes a molecule of RNA using DNA as a template.
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A) mRNA splicing B) translation C) transcription D) genesequencing E) termination
19)
Which base in an anticodon will pair with the base adenine in a codon? A) Thymine B) Cytosine C) Guanine D) Uracil
20)
A codon is composed of how many bases? A) 1 B) 2 C) 3 D) 4 E) 64
21)
In eukaryotes, translation takes place A) on the plasmamembrane. B) inside thenucleus. C) on ribosomes. D) on the nuclearmembrane. E) onspliceosomes.
22)
Ribosomes are complex aggregates of
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A) RNA and DNA. B) RNA andproteins. C) RNA and sugars. D) DNA and proteins. E) nucleosomes and RNA.
23) The A, P, and E sites are progressively occupied by amino acids being assembled into a polypeptide. These sites are part of A) DNA. B) the largeribosomal subunit. C) mRNA. D) tRNA. E) thespliceosome.
24)
In eukaryotic cells, transcription occurs A) on the surface ofthe nuclear membrane. B) on ribosomes. C) onspliceosomes. D) inside thenucleus. E) on the surface ofthe plasma membrane.
25) In prokaryotes, the form of RNA polymerase that can accurately initiate synthesis of RNA is called A) theholoenzyme. B) the corepolymerase. C) RNA polymeraseII. D) RNA polymeraseIII. E) the sigmasubunit.
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26) During_________blank, nucleotide sequence information is changed into amino acid sequence information. A) replication B) sequencing C) transcription D) translocation E) translation
27)
The genetic code uses _________ nucleotide(s) to specify one amino acid. A) one B) two C) three D) four E) 64
28)
Which statement about the genetic code is false? A) There is nopunctuation or spacing between codons. B) Nucleotides arealways read in groups of three. C) Every codon codesfor one amino acid. D) Some amino acidsare specified by more than one codon. E) The genetic code is almost universal,but not quite.
29) How many unique mRNA codons can be constructed from the four different RNA nucleotides?
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A) 4 B) 12 C) 16 D) 61 E) 64
30) During translation, the nucleotides that make up the mRNA are read in groups of three. These groups are called A) codons. B) anticodons. C) exons. D) introns. E) templates.
31)
The tRNA nucleotide sequence that pairs with bases on the mRNA is called a(n) A) intron. B) exon. C) codon. D) initiationfactor. E) anticodon.
32)
Ribosome movement along the mRNA is called A) transcription. B) initiation. C) replication. D) translocation. E) activation.
33)
Specific amino acids are attached to tRNA molecules by
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A) aminoacyl-tRNAsynthetases. B) hydrogenbonds. C) anticodons. D) deactivatingenzymes. E) initiation factors.
34)
Codons that serve as "stop" signals for translation are recognized by A) tRNA. B) releasefactors. C) anticodons. D) translationterminators. E) aminoacyl-tRNA synthetases
35) When a polypeptide is being assembled, the bond that forms between a newly added amino acid and the previous amino acid in the chain is a_________blank bond. A) hydrogen B) hydrophobic C) terminal D) phosphodiester E) peptide
36) During translation in prokaryotes, formation of the initiation complex requires all of the following except A) a small ribosomal subunit. B) mRNA. C) tRNA charged withN-formylmethionine. D) RNApolymerase. E) initiationfactors.
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37) Eukaryotic mRNA molecules may contain noncoding sequences that must be removed before translation. These are called A) anticodons. B) introns. C) exons. D) nucleosomes. E) noncodons.
38)
The location of translation in prokaryotic cells is A) in thenucleoid. B) on ribosomes. C) on the plasmamembrane. D) on mesosomes. E) on chromosomes
39)
In eukaryotes, pre-mRNA processing may involve all of the following except A) removal of exonsfrom the pre-mRNA. B) addition of a 5' cap. C) addition of a 3'poly-A tail D) pre-mRNA splicingby the spliceosome.
40) During translation, uncharged tRNA molecules leave the ribosome from the_________blank site.
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A) E B) P C) A D) termination E) release
41)
The Central Dogma of biology can be stated as A) Proteins→ RNA→ DNA. B) RNA→ DNA→ Proteins. C) DNA→ Proteins→ RNA. D) DNA→ RNA→ Proteins.
42) If the sequence of bases in the template strand of a DNA molecule is 3' ATCGCTCC 5', what is the sequence of bases in the RNA that is transcribed from this molecule? A) 3' UAGCGAGG 5' B) 3' TAGCGAGG 5' C) 5' UAGCGAGG 3' D) 5' TAGCGAGG 3' E) 5' AUCGCUCC 3'
43) The template strand of a DNA segment that codes for mRNA has the sequence: ATGCGT. Which tRNA anticodons would pair with the mRNA that is coded for by this sequence? A) AUG CGU. B) ATG CGT. C) UAC GCA. D) UAG CGU.
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44) Although 61 different codons code for amino acids, cells contain fewer than 61 different tRNAs. Why? A) Because the 5'base on the tRNA anticodon has some flexibility (wobble); thus, some tRNAanticodons can pair with more than one mRNA codon. B) Although 61different codons code for amino acids, any given cell contains fewer than61. C) Because the5' base on the mRNA codon has some flexibility (wobble); thus, some mRNAcodons can pair with more than one tRNA anticodon. D) Because each aminoacid is coded for by just one codon.
45) Eukaryotic and prokaryotic organisms differ in how they process genetic information. Which statements best explain one of these differences? A) In prokaryotes, translation of the mRNA begins before transcription is complete. In eukaryotes, transcription and modification of the mRNA is completed before translation begins. B) In prokaryotes, genes are transcribed directly into polypeptides. In eukaryotes, genes are transcribed into RNA which is used to assemble polypeptides. C) In prokaryotes, translation occurs before genes are transcribed into mRNA. In eukaryotes, genes are transcribed into mRNA which is then translated into polypeptides. D) In prokaryotes, introns are removed before genes are transcribed into mRNA. In eukaryotes, introns are removed after genes are transcribed into mRNA.
46)
What is the first step during transcription initiation in prokaryotes? A) The transcription bubble is formed B) RNA polymerase binds to the promoter C) The DNA double helix is unwound D) RNA polymerasesynthesizes a short primer E) Transcription factors bind to the TATA box sequence
47) Initiation of transcription differs from initiation of DNA replication in several ways. One difference is that initiation of transcription does not require
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A) a promoter. B) enzymes. C) a primer. D) a DNA template strand.
48) Transcription in prokaryotes is carried out by_________blank, which unwind(s) and transcribe(s) the gene. A) RNA synthetase B) RNA polymeraseII C) RNA polymeraseIII D) transcriptionfactors E) RNA polymerase
49)
Eukaryotes have_________blank type(s) of RNA polymerase. A) one B) two C) three D) four E) 64
50)
In eukaryotes, each type of RNA polymerase recognizes a different A) start codon. B) stop codon. C) promoter. D) release factor. E) transcription factor.
51)
Eukaryotic pre-mRNA molecules are modified
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A) in the cytoplasm. B) at the ribosome. C) inside thenucleus. D) as they passthrough the nuclear membrane. E) at thetranscription bubble.
52)
In eukaryotes, the 3' poly-A tail is attached to A) poly-Apolymerase. B) mRNA. C) tRNA. D) the ribosome. E) the templatestrand of DNA.
53) Why are there fewer tRNA anticodons than the 61 needed to match each mRNA codon that codes for an amino acid? A) There is someflexibility in pairing between the 5' base of the codon and the 3' base of theanticodon. B) There is someflexibility in pairing between the middle base of the codon and the middlebase of the anticodon. C) There is someflexibility in pairing between the 3' base of the codon and the 5' base of theanticodon. D) There is someflexibility in pairing between all 3 bases of the codon and all 3 bases ofthe anticodon.
54)
During protein synthesis in eukaryotes, what happens during RNA splicing?
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A) The product oftranslation, called the primary transcript, is cut and some pieces arejoined back together to form the mature mRNA. B) The product oftranscription, called the primary transcript, is cut and some pieces are joinedback together to form the mature tRNA. C) The product oftranscription, called the secondary transcript, is cut and some piecesare joined back together to form the mature mRNA. D) The product oftranscription, called the primary transcript, is cut and some piecesare joined back together to form the mature mRNA. E) The product oftranscription, called the primary transcript, is cut and all piecesare joined back together to form the mature mRNA.
55) During protein synthesis in eukaryotes, which molecule passes from the nucleus to the cytoplasm and specifies the sequence of amino acids in the new polypeptide? A) DNA B) RNA polymerase C) mRNA D) rRNA E) tRNA
56) Which molecule combines with proteins to form both the large and small ribosomal subunits? A) DNA B) RNA polymerase C) miRNA D) rRNA E) tRNA
57) Given the sentence "THE FAT CAT ATE THE RED RAT," which of the following would represent a frameshift mutation?
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A) THE FAT RAT ATETHE RED CAT B) THE CAT ATE THE RED RAT C) THE FAC ATA TET HER EDR AT D) THE FAT CAT ATE THERED RAT
58)
What would happen if snRNPs did not recognize the branch point within an intron? A) A lariat wouldnot form. B) snRNPs would not base-pair with the 5' end of the intron. C) A 3' poly A tailwould not be added to the transcript. D) A 5' cap wouldnot be added to the transcript.
59)
During the splicing reaction, the intron-exon junctions are recognized by A) snRNPs. B) miRNAs. C) SRP RNAs. D) the lariat. E) the branch point.
60)
In prokaryotes, the RNA polymerase holoenzyme consists of A) the core polymeraseplus two alpha subunits. B) the core polymeraseplus two beta subunits. C) the core polymeraseplus two alpha subunits, two beta subunits, and a sigma subunit. D) the corepolymerase plus a sigma subunit. E) two alpha subunits, two beta subunits,and two sigma subunits.
61) Two 6-base sequences are present in bacterial promoters: TATAAT (located 10 nt upstream from the start site) and TTGACA (located 35 nt upstream from the start site). What is the significance of the fact that these two base sequences are different?
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A) Binding sites forboth the holoenzyme and ATP are provided. B) Both the locationof the start site and the direction of transcription can be established. C) Binding sites forboth the core polymerase and holoenzyme are provided. D) The transcription bubble can be properly formed. E) It allows RNA polymerase to distinguishbetween the template strand and the coding strand of the DNA molecule.
62) Within the transcription bubble, the 9 most recently added nucleotides in the newly synthesized RNA strand temporarily form a helix with the template DNA strand. How might transcription be affected if helix formation did not occur? A) Rewinding the DNAmolecule would be inhibited. B) Unwinding the DNAmolecule would be inhibited. C) The position of the5' end of the RNA would be unstable, inhibiting elongation. D) The position of the3' end of the RNA would be unstable, inhibiting elongation. E) The position of the 5' end of the RNAwould be unstable, stimulating elongation.
63) Cells conserve energy and resources by making active proteins only when they are needed. If a protein is not needed, which of the following methods of control would be the most energy-efficient? A) Block transcription B) Degrade the mRNA after it is made C) Prevent translation of the mRNA D) Degrade the protein after it is made
64)
What is required for formation of the transcription initiation complex in eukaryotes?
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A) Binding of a transcription factor to the TATA box, followed by recruitment of additional transcription factors and recruitment of RNA polymerase II B) Binding of a transcription factor to the transcription bubble, followed by recruitment of additional transcription factors and recruitment of RNA polymerase III C) Binding of the sigma subunit to the start site followed by recruitment of RNA polymerase II D) Binding of RNA polymerase II to the TATA box, followed by recruitment of transcription factors E) Binding of the sigma subunit to promoter elements at -35 and -10, followed by recruitment of the core polymerase
65) What is the likely consequence of a mutation that alters the branch point within an intron? A) No effect, since introns are not expressed B) Failure to form a lariat C) Failure of snRNPs to recognize the 5' end of intron D) No exon shuffling E) Failure of snRNAs to combine with protein and form snRNPs
66) You are working to characterize a novel protein in mice. Analysis shows that high levels of the primary transcript that codes for this protein are found in tissue from the brain, muscle, liver, and pancreas. However, an antibody that recognizes the C-terminal portion of the protein indicates that the protein is present in brain, muscle, and liver, but not in the pancreas. What is the most likely explanation for this result? A) The gene that codes for this protein is not transcribed in the pancreas. B) The transcript is immediately degraded in the pancreas. C) The transcript receives a 5’ cap in the pancreas. D) Alternative splicing in the pancreas creates a protein missing the domain that the antibody recognizes. E) The transcript receives a 3’ poly-A tail in the pancreas.
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67)
The mutation responsible for Huntington's disease is a A) missensemutation. B) nonsense mutation. C) frameshift mutation. D) triplet repeat expansion mutation.
68) How would a large chromosomal inversion affect the expression of a gene if the gene is located between the two break points but no breaks occur within the gene? A) The inversionwould probably have no effect on gene expression. B) The gene would notbe transcribed because it would be oriented in the wrong direction. C) The gene would betranscribed in the 3' to 5' direction. D) The gene would betranscribed normally but the mRNA would be translated in the 3' to 5'direction.
69)
How does DNA polymerase differ from RNA polymerase?
A) Only RNA polymeraseadds new nucleotides to the 3' end of a growing chain. B) Only RNA polymeraserequires a primer. C) Only DNA polymeraseuses a template DNA strand to direct synthesis of a new nucleotide strand. D) Only DNApolymerase has a proofreading ability.
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70) A scientist makes three artificial mRNA strands:(x) 5' AAAUUUAAAUUUAAAUUUAAAUUUAAA 3' (y) 5' UUUCCCUUUCCCUUUCCCUUUCCCUUU 3' (z) 5' AUAUAUAUAUAUAUAUAUAUAUAUAU 3' When she analyzes the polypeptides produced, she finds that: x produces a polypeptide that is 50% phenylalanine and 50%lysine. y produces a polypeptide that is 50% phenylalanine and 50% proline. z produces a polypeptide that is 50% isoleucine and 50% tyrosine. Based on these results only, the best conclusion to make is that A) AUA codes forisoleucine B) AAA codes forphenylalanine C) AAA codes forlysine D) AAA codes forlysine and AUA codes for isoleucine E) AAA codes for phenylalanine and AUAcodes for isoleucine
71) A bacterial cell has a nonsense mutation that prevents it from producing a functional sigma subunit for RNA polymerase. Inability to synthesize a functional sigma subunit would have the most direct effect on A) transcriptioninitiation. B) transcriptionelongation. C) transcriptiontermination. D) translationinitiation. E) translation termination.
72) What is the best way to describe our current understanding of the one-gene/onepolypeptide hypothesis? A) It continues to be an accurate description of how genes work. B) It is oversimplified, especially in eukaryotes. C) It has been replaced by the more accurate “one-gene/one-enzyme” hypothesis. D) It was true for fungi like Neurospora, but not for other species.
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73) You are attempting to synthesize rRNA in a test tube using DNA isolated from mouse cells. In addition to the template DNA, ribonucleotides, and the necessary transcription factors, you should also add _________blank to the test tube. A) poly-Apolymerase B) RNA polymeraseIII C) RNA polymeraseII D) RNA polymeraseI
74) You are studying an individual with very low levels of insulin in her blood. Further analysis indicates that cells of her pancreas are producing normal levels of this protein, but it is accumulating in the cytoplasm rather than being secreted from the cells. Which hypothesis makes the most sense to explain this observation? A) A small deletion has removed the nucleotides that code for the signal sequence at the amino terminus of the protein. B) A missense mutationhas caused premature termination during translation of this protein. C) A chromosomalsegment that includes the gene for insulin has been inverted. D) A two-basedeletion near the middle of the gene has altered the reading frame duringtranslation of the protein. E) A missense mutation has altered theribosome-binding sequence at the 5' end of the mRNA.
75) A gene that codes for a protein was removed from a eukaryotic cell and inserted into a prokaryotic cell. Although the gene was successfully transcribed and translated, it produced a different protein than it produced in the eukaryotic cell. What is the most likely explanation? A) There are slightdifferences in the genetic code for prokaryotes and eukaryotes. B) Unlike eukaryotes,which have three different RNA polymerases, prokaryotes have a single RNApolymerase. C) Eukaryotic genesoften contain introns while prokaryotic genes do not. D) Eukaryotictranscripts have a 5' cap while prokaryotic transcripts do not.
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76) Why are duplications of chromosomal regions suspected to be especially important to evolution? A) Duplications result in increased protein production, and thus make an individual more fit. B) Duplications often result in a large number of point mutations creating lots of immediate genetic diversity on which natural selection can act. C) Duplications result in two copies of a gene or genes, thus allowing one copy to perform as normal and the other to become modified and selected for without immediate deleterious effects. D) Duplications are the primary mechanism of introducing genetic variation to DNA.
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Answer Key Test name: Chap 15_13e_Raven 1) A 2) B 3) C 4) D 5) A 6) B 7) D 8) B 9) A 10) C 11) A 12) D 13) C 14) A 15) E 16) A 17) B 18) C 19) D 20) C 21) C 22) B 23) B 24) D 25) A 26) E Version 1
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27) C 28) C 29) E 30) A 31) E 32) D 33) A 34) B 35) E 36) D 37) B 38) B 39) A 40) A 41) D 42) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses transcription. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o The template strand of the DNA is the strand used to make the RNA copy. The RNA is paired up with the template strand, so it is complementary to it, not the same. o The 3’ and 5’ designations show the directionality of each strand. The two paired strands go in opposite directions. Gather Content • What do you already know about transcription? o Transcription is the process of making an RNA copy off the DNA. o After the DNA opens up, one strand is the coding strand, the other is the template strand. o The template strand is the one directly used to make the RNA, by base-pairing. Therefore it is the complementary sequence to the RNA, not the same sequence. Consider Possibilities • Consider the different answer options. Which can you rule out? o Is the RNA the same as the template strand, or is it complementary to the template strand of DNA? The RNA is complementary to the template strand. So you can rule out the answer that shows the RNA with the same sequence as the template strand (5’ AUCGCUCC 3’). o What is different about the bases in RNA compared to DNA? RNA Version 1
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uses U instead of T. So we can rule out the answers that include T’s in the RNA. o What is the directionality of the RNA compared to the template strand? The RNA is formed by base-pairing to the template strand, so the strands run in opposite directions. You can rule out the answers that would base pair with both strands running 3’ to 5’. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o We know that the RNA is produced by base-pairing to the tempate strand, with strand directionality in the opposite direction, and using U’s instead of Ts. o Thus the RNA will be 5’ UAGCGAGG 3’. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to name the RNA that would result from a given template DNA sequence. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that the RNA is complementary to the template strand, not the same? o Did you remember that RNA contains U, not T? o Did you remember that the paired strands are oriented in opposite directions, so the RNA should read 5’ to 3’? 43) A Version 1
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Clarify Question • What is the key concept addressed by the question? o This question addresses transcription and translation. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o The template strand of the DNA is the strand used to make the RNA copy. The RNA is paired up with the template strand, so it is complementary to it, not the same. o The tRNA anticodons are the three nucleotide sequences that basepair with each codon of the mRNA. Each tRNA has one anticodon and carries one amino acid. Gather Content • What do you already know about transcription and translation? o You know that there are several steps from DNA to tRNAs. The DNA is transcribed into mRNA, then the mRNA is translated by the ribosome using tRNAs whose anticodons base pair with the mRNA. Consider Possibilities • Consider the different answer options. Which can you rule out? o What is different about the bases in RNA compared to DNA? RNA uses U, not T. This is true for tRNA as well as mRNA. So you can rule out the answer with T in the RNA. Choose Answer • Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer? o What specifically are you being asked to describe? The question is asking you to name the tRNA anticodons that relate to the given DNA template strand. So you need to determine the corresponding mRNA, and then determine which anticodons would pair with the mRNA. o Is an mRNA the same as its DNA template strand, or complementary to it? The mRNA is complementary to the sequence of the template strand, because it is transcribed by base-pairing to it. So the mRNA is UACGCA. o The tRNAs have to base pair to the mRNA. So the tRNAs would read AUG CGU. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to describe the tRNA anticodons that correspond to a given DNA template strand sequence. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that the mRNA is complementary to the DNA template strand? o Did you recognize that the tRNAs would be complementary to the mRNA? o Did you remember that RNAs always use U instead of T? 44) A 45) A 46) B 47) C 48) E Version 1
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49) C 50) C 51) C 52) B 53) C 54) D 55) C 56) D 57) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses frameshift mutations. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o A frameshift mutation is a change in the DNA that shifts the reading frame. Gather Content • What do you already know about frameshift mutations? o A framshift mutation causes the bases to be read in different groups of three, so that the new codons no longer encode the same amino acids. o An insertion or deletion of nucleotides will cause a frameshift – unless it happens to insert or delete three nucleotides or a multiple of three. Consider Possibilities • Consider the different answer options. Which can you rule out? o Does a frameshift mutation switch around portions of the gene? No. So you can rule out the answer that switches CAT and RAT. o Is a three nucleotide deletion a type of frameshift mutation? No, because despite the deletion the reading frame further on stays the same. So you can rule out THE CAT ATE THE RED RAT. o Can a frameshift mutation appear to have no effect? No, it has a dramatic effect and you can see the shift in the sequence. So you can rule out the answer THE FAT CAT ATE THE RED RAT. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o What is a frameshift mutation in DNA? An insertion or deletion that shifts the reading frame. o What is the result of a frameshift mutation? It changes the codons downstream of the mutation, usually into gibberish (wrong amino acids that don’t make a functioning protein). o So the answer option THE FAC ATA TET HER EDR AT is a good representation of a frameshift mutation. A single nucleotide deletion causes a shift in the frame that turns the codons downstream into gibberish. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to choose the option that represents a frameshift mutation. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that the key feature of a frameshift mutation is that it shifts the reading frame, messing up all the codons downstream? 58) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses splicing. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o The snRNPs are small nuclear ribonucleoprotein particles, the complexes that carry out splicing. o An intron is a portion of the sequence of a pre-mRNA that is removed by splicing. o The branch point is a particular adenosine nucleotide that lies within the intron and is recognized by snRNPs during the splicing process. Gather Content • What do you already know about splicing? o Splicing is the process that removes introns from pre-mRNA. o Splicing is carried out by the spliceosome, a complex formed of snRNPs. o The snRNPs bind to specific sites on the 5’ end of the intron and to the branch point near the 3’ end. The snRNPs come together, forming the intron into a lariat, which is cut as the exons are joined together. Consider Possibilities • Consider the different answer options. Which can you rule out? o Are snRNPs involved in adding the 3’ poly-A tail? No, they are involved in splicing out introns. So you can rule out the answer about the poly-A tail. o Are snRNPs involved in adding the 5’ cap? No, they are involved in Version 1
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splicing out introns. So you can rule out the answer about the 5’ cap. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The snRNPs bind at the 5’ end and at the branch point near the 3’ end. Then by coming together, the two sets of snRNPs create the lariat which is cleaved as the exons are ligated. o If the snRNPs couldn’t recognize the branch point, they could still recognize and bind the 5’ end. o However, the lariat would fail to form. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what would result if snRNPs couldn’t recognize the branch point of an intron. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that the branch point is near the 3’ end? o Did you recognize that binding the branch point is critical for lariat formation? 59) A 60) D 61) B 62) D 63) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses transcription and translation. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o Energy in a cell refers to chemical energy, stored in molecules like ATP. o Proteins are the final output from the transcription and translation of DNA; they are made of amino acids. o Energy-efficient means energy-saving. Gather Content • What do you already know about transcription and translation? o Transcription is the process of turning the stored information from a DNA sequence and turning it into a temporary mRNA copy. o Translation takes the information from mRNA and turns it into a protein, or polypeptide – a string of amino acids. o What is meant by “energy-efficient”? How would making an unnecessary protein waste energy? Because both transcription and translation require energy in the form of ATP to drive the enzymes to carry out the work. o They also use up ribonucleotides and amino acids, which were produced using more energy from ATP. Consider Possibilities • Consider the different answer options. Which can you rule out? o For each answer option, consider what energy-consuming process(es) Version 1
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would still take place. o If the protein is degraded after it is made, transcription and translation both took place, using up ATP, ribonucleotides, and amino acids. o If the mRNA is not translated, or is degraded, then transcription still took place, using up ATP and ribonucleotides. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Only by blocking transcription can the cell save all that energy. If the gene is never transcribed, then ATP, ribonucleotides, and amino acids are all saved. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked which method of control would be most energyefficient for the cell? o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that blocking transcription would save the most energy? o Despite this, cells do often regulate at the level of translation as well. Why do you think this might benefit a cell despite the wasted energy? 64) A 65) B
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Clarify Question • What is the key concept addressed by the question? o This question addresses splicing. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o An intron is a portion of the sequence of a pre-mRNA that is removed by splicing. o The branch point is a particular adenosine nucleotide that lies within the intron and is recognized by snRNPs during the splicing process. Gather Content • What do you already know about splicing? o Splicing is the process that removes introns from pre-mRNA. o Splicing is carried out by the spliceosome, a complex formed of snRNPs. o The snRNPs bind to specific sites on the 5’ end of the intron and to the branch point near the 3’ end. The snRNPs come together, forming the intron into a lariat, which is cut as the exons are joined together. Consider Possibilities • Consider the different answer options. Which can you rule out? o Is there no effect, since introns are not expressed? Well, the effect is likely to be that the intron will become expressed – this will have a big effect on the resulting protein. o Will it affect exon shuffling? Not likely, since exon shuffling is an evolutionary process that is not dependent on the branch point. o Will snRNAs fail to combine with their proteins? No, because that Version 1
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happens independently of any particular intron. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The snRNPs bind at the 5’ end and at the branch point near the 3’ end. Then by coming together, the two sets of snRNPs create the lariat which is cleaved as the exons are ligated. o If the snRNPs couldn’t recognize the branch point, they could still recognize and bind the 5’ end. o However, the lariat would fail to form. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what would result if snRNPs couldn’t recognize the branch point of an intron. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that the branch point is near the 3’ end? o Did you recognize that binding the branch point is critical for lariat formation? 66) D
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Clarify Question • What is the key concept addressed by the question? o This question addresses post-transcriptional regulatory mechanisms. • What type of thinking is required? o This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. • What key words does the question contain and what do they mean? o A novel protein is one that has just recently been discovered, and isn’t well understood by scientists. o The primary transcript is the initial pre-mRNA transcript before splicing takes place. o The C-terminal portion of a protein is the end near the final –COOH. Gather Content • What do you already know about post-transcriptional regulatory mechanisms? o Cells use several kinds of post-transcriptional regulatory mechanisms. o A gene can be transcribed or not in different cells, or the transcript can be degraded. o Alternative splicing creates proteins with different domains. o Most mRNAs receive a 5’ cap and poly-A tail to improve stability. Consider Possibilities • Consider the different answer options. Which can you rule out? o Could the gene not be transcribed in the pancreas, or the transcript degraded? No, because we are told that the primary transcript was found in the pancreas. o Could the addition of a 5’ cap or 3’ poly-A tail in the pancreas explain the data? No. Most transcripts get those anyway, and they only improve Version 1
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stability and the likelihood of translation into protein. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o What could explain why the antibody reacts with the protein in some cells but not others? Either the protein is not present in the pancreas cells, or the protein is different and not recognizable by the antibody. o What types of regulation lead to different sets of proteins in different cells? In addition to transcriptional regulation, alternative splicing is a mechanism that ensures that different cell types produce specialized sets of proteins. o The best explanation of the answer options is that alternative splicing produced a different form of the protein in pancreas cells, that could not be recognized by the antibody. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked for the best explanation for the presence of transcript but no apparent protein in one cell type. o The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. o Did you recognize that the regulation must be post-transcriptional? o Did you realize that antibodies may recognize only a portion of a protein? 67) D 68) A Version 1
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69) D 70) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses the genetic code. • What type of thinking is required? o This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. • What key words does the question contain and what do they mean? o Artificial mRNAs are similar to mRNAs in a cell, but they were designed by a scientist and produced in vitro. o Polypeptides are proteins – in this case, resulting from translation of the artificial mRNAs. Gather Content • What do you already know about the genetic code? o The genetic code was elucidated by experiments similar to this one. o By producing artificial mRNAs with a defined sequence, Nirenberg and Khorana could infer the sequence of codons that encoded each amino acid. Consider Possibilities • Consider the different answer options. Which can you rule out? o Is there enough information to say anything about what AUA encodes? No, because it could either be isoleucine or tyrosine. We don’t have enough information to distinguish between them. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o Is there enough information to say what AAA encodes? Yes. o From experiment (x), we know that the AAA and UUU together make phenylalanine and lysine. But we don’t know which is which. o From experiment (y), we know that the CCC and UUU together make phenylalanine and proline. But we don’t know which is which. o Putting both together, we realize that UUU must encode phenylalanine, since that codon and that amino acid are in both experiments. o That means that AAA must make the other amino acid from experiment (x), namely lysine. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what conclusion you could draw about what codons encode what amino acids. o The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. o Did you recognize that you needed to use experiment (x) and (y) together to determine what AAA encoded? 71) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses RNA polymerase. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o A nonsense mutation is one that causes an early STOP codon, resulting in a protein that is shorter than normal. o RNA polymerase is the enzyme that transcribes DNA into mRNA. o The sigma (σ) subunit of RNA polymerase is important in transcription initiation. Gather Content • What do you already know about RNA polymerase? o RNA polymerase is the enzyme that does transcription – it produces RNA. o There are three main steps to transcription: initiation, elongation, and termination. o Initiation requires the polymerase to recognize and bind to the promoter. Promoter binding is controlled by the σ subunit, which recognizes the –35 sequence in the promoter and positions the RNA polymerase at the correct start site, oriented to transcribe in the correct direction. Consider Possibilities • Consider the different answer options. Which can you rule out? o Is the sigma subunit of RNA polymerase likely to be important for translation? No, because RNA polymerase is used in transcription, not Version 1
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translation. The ribosome is the enzyme that carries out translation. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Of the three aspects of transcription, loss of the sigma subunit is likely to disrupt initiation, because the sigma subunit is necessary to recognize and bind the promoter. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what would result from a missing RNA polymerase sigma subunit. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that RNA polymerase acts in transcription, not translation? o Did you remember that the sigma subunit binds the promoter? 72) B 73) D
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Clarify Question • What is the key concept addressed by the question? o This question addresses RNA polymerases. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o Ribosomal RNA, or rRNA, is the RNA component of the ribosome. o Template DNA is the DNA that is used to transcribe an RNA. o Ribonucleotides are the building blocks of RNA. o Transcription factors are proteins that help carry out and regulate transcription. Gather Content • What do you already know about RNA polymerases? o RNA polymerases are the enzymes that carry out transcription. o There are three kinds in eukaryotes (like mice): RNA Polymerase I, II, and III, each with specialized functions. o RNA Polymerase I transcribes rRNA. o RNA Polymerase II transcribes mRNA and snRNAs. o RNA Polymerase I transcribes tRNA and some other small RNAs. Consider Possibilities • Consider the different answer options. Which can you rule out? o Would it make sense to add poly-A polymerase? No, only mRNAs are polyadenylated. Ribosomal RNAs are not. Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o To decide which RNA polymerase should be added, you must remember that they each have specialized target genes, and that RNA Polymerase I is the enzyme that transcribes rRNA. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked which enzyme was necessary to carry out transcription of rRNA. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you remember that RNA Polymerase I is specialized to transcribe rRNA? 74) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses transcription and translation. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o Insulin is a protein produced by the pancreas, that plays a critical role in blood sugar regulation. o If the protein is accumulating in the cytoplasm rather than being secreted, that means it is building up inside the cells instead of being released from the cells. Gather Content • What do you already know about transcription and translation? o Different mutations will affect transcription and translation differently. o First, a protein like insulin is transcribed into mRNA. Then the mRNA is translated. o A secreted protein like insulin will be synthesized on the rough ER (RER) so that the protein ends up in the lumen of the ER, ready for release by the cell. A signal sequence on the amino terminus of the polypeptide is responsible for recognition of the peptide by the SRP, and docking onto the RER. Consider Possibilities • Consider the different answer options. Which can you rule out? o Could an inversion of the gene explain the lack of secretion? No, it’s not apparent why that would affect secretion. Version 1
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o Could a mutation in the ribosome-binding sequence explain the lack of secretion? No, because then there wouldn’t be protein produced at all. o Could a premature termination or a change in reading frame explain the lack of secretion? No, because then there wouldn’t be full-length protein produced. (Disruption of the reading frame typically creates early STOP codons.) Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o What specifically seems to be wrong with the insulin protein in this individual? The protein is being produced fine, just not secreted. o What type of mutation could interfere with that specific aspect? A mutation must have disrupted the signal sequence, which helps the growing peptide dock at the ER for later secretion. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what type of mutation could best explain lack of insulin secretion. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that lack of secretion indicates a problem with the signal sequence on the ER? 75) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses transcription and translation. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o A eukaryotic cell is from an organism with a nucleus, like a human, fly, plant, or fungus. o A prokaryotic cell is a single-celled organism such as a bacterium like E. coli. Gather Content • What do you already know about transcription and translation? o There are some key differences in transcription and translation between eukaryotes and prokaryotes. o One of the main differences is that eukaryotic genes typically have introns, which are spliced out of the pre-mRNA by specialized splicing machinery. Prokaryotes do not have introns or the machinery to splice them out. Consider Possibilities • Consider the different answer options. Which can you rule out? o Could the different RNA polymerases explain the change in the protein? No, that doesn’t make sense. o Could the 5’ cap explain the change in the protein? No, because that affects stability but not the sequence of the protein itself. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The best explanation is that the eukaryotic gene contained introns. In a prokaryote they would not be removed, so the protein would have extra sections of translated sequence. o For this reason, scientists usually use a cDNA, or complementary DNA copy from a processed mRNA, rather than the DNA gene itself when they clone a eukaryotic gene into bacteria for protein expression. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked why a eukaryotic gene would not produce the same protein in a prokaryote. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that prokaryotes lack the splicing machinery? 76) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses structural variation in chromosomes. • What type of thinking is required? o This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. • What key words does the question contain and what do they mean? o Duplications are a specific type of copy number variation possible that affects the structure of chromosomes. Gather Content • What do you already know about chromosomal structure and evolution? o Chromosomes contain the DNA of an organism and can experience different mutations that affect their structure in different ways. The simplist mutations are point mutations, those affecting less than 50 bp, and include frameshift mutations, missense mutaitons, and nonsense mutations. Larger scale mutations can change the number of copies of particular genomic regions and include deletions, insertions, and duplications. o Evolution is driven by the process of natural selection acting on genetic variation present in a population to increase the frequency of benificial alleles. For evolution to occur, their must be sufficient genetic variation in the population on which selection can act. Consider Possibilities • Consider the different answer options. Which can you rule out? o This question is specifically asking about duplications. While multiple copies of a gene would result in increased protein production, that does Version 1
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not necessarily translate to increased fitness. Duplications do not inherently coincide with many point mutations, so they do not inject a large amount of genetic variation when then occur. Duplications are also not the primary mechanism by which genetic diversity is introduced into a population. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Duplications result in two copies of a gene or genes being present in an individual which can allow for functional divergence of one of the two copies while the other copy continues to function as normal. This process is facilitated by the fact that with a functional copy present, the other copy is free to collect additional mutations and change into a potentially more beneficial allele without the organism experiencing the typical deleterious effects of mutations in necessary genes. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to relate chromosomal structural variation to the process of evolution. o The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. o Did you recognize how genetic variation can be introduced? o Did you understand the significance of having multiple copies of a single gene as related to the process of natural selection?
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Chapter 16 13e CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 1) Control of gene expression_________blank. (Select all that apply) A) allows bacteria to adapt to changing environments B) is critical for development in multicellular organisms C) allows bacteria to replicate without control D) allows multicellular organisms to maintain homeostasis E) it stops multicellular organisms functioning as a whole
2) Examples of shapes in regulatory proteins that are used to bind to DNA include_________blank. (Select all that apply) A) zinc finger B) TATA box C) helix-turn-helix D) leucine zipper E) Doubledomain
3) A bacterial gene regulatory system is likely to have_________blank. (Select all that apply) A) a coding sequence B) an operator C) one or more introns D) a motor E) a ribosome recognition site
4) Control of the lac operon and lactose utilization in bacteria is_________blank. (Select all that apply)
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A) not induced in the presence of both glucose and lactose B) only induced when there is glucose but not lactose C) is a negative control, mediated by a repressor D) controlled by the expression of three downstream genes E) preferentially utilizing lactose as a carbon source
5)
The eukaryotic transcription initiation complex is_________blank. (Select all that apply)
A) transcription of virtually all genes transcribed by RNA pol II requiring the same suite of general factors B) responsible for highly regulated transcription levels C) only associated with RNA polymerase I D) interactive with activators through DNA looping E) a basal factor associated with RNA pol II after positioning RNA pol II at the start site
6)
The ubiquitin-proteasome pathway_________blank. (Select all that apply)
A) is used to regulate expression of a number of cell surface receptors B) requires only one molecule of ATP to target a protein C) targets proteins in a stepwise fashion via ubiquitin ligase adding ubiquitin residues to the protein D) is used to digest macromolecules E) does not destroy the ubiquitin moiety, but rather cleaves it off for reuse
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 7) In order for transcription to be initiated
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A) DNA polymerase musthave access to the DNA double helix and must also be capable of binding tothe gene's promoter. B) RNA polymerase musthave access to the DNA double helix and must also be capable of binding tothe gene's promoter. C) DNA polymerase musthave access to the RNA and must also be capable of binding to the gene'spromoter. D) RNA ligase musthave access to the DNA double helix and must also be capable of binding tothe gene's promoter. E) RNA polymerase musthave access to the DNA double helix and also must be capable of binding to thegene's operator.
8) In some organisms, the primary function of a gene in a cell is to participate in regulating the body as a whole rather than responding to the cell's immediate environment. These organisms would be A) multicellular. B) diploid. C) bacterial. D) prokaryotic.
9)
The maintenance of a constant environment in a cell is called_________blank. A) active transport B) homeostasis C) gene expression D) translation
10) Through control of gene expression, a bacterial cell responds to changing_________blank conditions.
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A) internal B) protein C) environmental D) genetic
11) A site at the 5' end of a gene where RNA polymerase attaches to initiate transcription is called a(n) A) operon. B) repressor. C) promoter. D) operator. E) CAP.
12) In multicellular organisms, the mechanism most directly responsible for directing development and maintaining homeostasis is gene A) mutation. B) duplication. C) deletion. D) regulation.
13)
The basic tool of genetic regulation is the ability of certain proteins to bind to specific A) regulatory RNA sequences. B) regulatory DNA sequences. C) repressor parts of the gene. D) promoter parts of the gene. E) enzymes of the cell.
14)
The hallmark of multicellular organisms is their ability to
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A) grow and dividerapidly. B) adjust quickly tooutside environment. C) maintainhomeostasis. D) quickly synthesizeamount and type of enzymes according to available nutrients. E) respond by geneaction to oxygen availability.
15)
A defining characteristic of eukaryotic organisms is that A) transcription occurs in the cytoplasm and translation in the nucleus. B) transcription occurs in the nucleus and translation in the cytoplasm. C) only have operons to assist in gene expression. D) they carry out protein synthesis only in the presence of the cAMP molecule. E) they use the leucine zipper primarily for the production of the amino acid tryptophan.
16) As a microbiologist you have been asked to investigate the regulation of a novel gene in a bacterial species. Given what is known about bacteria, the logical place to begin your investigation is A) transcriptional regulation. B) translational regulation. C) alternative splicing regulation. D) regulation by enhancer elements. E) regulation by general transcription factors.
17)
Certain proteins can bind to specific DNA regulatory sequences by entering A) the major grooveof the DNA and reading the nucleotide base pairs. B) the minor grooveof the DNA and reading the nucleotide base pairs. C) the major grooveof RNA and reading the nucleotide base pairs. D) DNA's major grooveby using DNA polymerase and reading the nucleotide base pairs. E) DNA's minor grooveby using DNA polymerase and reading the nucleotide base pairs.
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18) Regulatory proteins can identify specific sequences on the DNA double helix without unwinding the helix. This is accomplished by inserting A) RNA promoters intoeither the major groove or the minor groove of the double helix where the edgesof the nitrogen bases protrude. B) DNA-binding motifsinto the minor groove of the double helix where the edges of the nitrogen basesprotrude. C) DNA polymeraseinto the major groove of the double helix where the edges of the nitrogen basesprotrude. D) RNA polymeraseinto the major groove of the double helix where the edges of the nitrogen basesprotrude. E) DNA-binding motifsinto the major groove of the double helix where the edges of the nitrogen basesprotrude.
19) You have been asked to design a synthetic DNA motif, able to bind transcriptional regulatory proteins. The location on this motif that you will design for protein binding is the A) minor groove of the DNA double helix. B) major groove of the DNA double helix. C) phosphate backbone of the DNA double helix. D) sugar backbone of the DNA double helix. E) available hydrogen-bonds of bases in single-stranded DNA.
20) The DNA-binding proteins of almost all regulatory proteins use one of a small set of shapes that enable them to fit into the DNA major groove. These shapes are called A) structural motifs. B) DNA prints. C) fingerprints. D) repressors. E) transcriptional domains.
21) One of the DNA-binding motifs in many eukaryotic organisms that contains a nearly identical sequence of 60 amino acids is known as the
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A) nonhelical zipper. B) leucine zipper. C) zinc finger. D) homeodomain. E) helix-turn-helix.
22)
The most common DNA-binding motif is the A) nonhelical zipper. B) leucine zipper. C) zinc finger. D) homeodomain. E) helix-turn-helix.
23) You lead a research team challenged with the task of creating a regulatory protein able to shut off transcription of a particular gene. You focus your design around a binding site called an operator that is associated with the promotor. The physical location of the operator most likely to affect transcription would be A) upstream of thegene promoter. B) downstream of thegene promoter. C) internal to thegene itself. D) internal to thegene promoter.
24)
A protein that regulates transcription by binding to the operator is known as the A) operon. B) repressor. C) promoter. D) operator. E) CAP.
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25) A cluster of functionally-related genes that are regulated together and encoded into a single mRNA molecule is called a(n) A) operon. B) repressor. C) promoter. D) operator. E) CAP.
26) the
A site of negative genetic regulation where binding by repressor blocks transcription is
A) operon. B) repressor. C) promoter. D) operator. E) CAP.
27)
The main form of glucose repression in the lac operon is A) induction. B) repression. C) inducer exclusion. D) the CAP/cAMP system.
28) The enzyme beta-galactosidase acts on lactose to form galactose. In turn, the presence of galactose leads to expression of the enzymes responsible for the metabolism of galactose. In this case, lactose is serving as a carbon source and as a(n) A) inducer. B) repressor. C) DNA-binding protein. D) operon.
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29) The lactose analog isopropyl-beta-D-thio-galactoside (IPTG) is often used to regulate gene expression systems in bacteria. IPTG does not act as a substrate for beta-galactosidase, but can bind to, and inactivate, the repressor. In this case, IPTG serves as a(n) A) inducer. B) repressor. C) DNA-binding protein. D) operon.
30) You are studying regulation of a prokaryotic operon. Experiments show that expression of the operon is increased when levels of biosynthetic product from that pathway are low. Based on this information, what is a likely mode of regulation? A) The product binds a repressor, allowing it to bind the operator. B) The product binds an activator, helping RNA polymerase to bind the promoter. C) The product binds a repressor, preventing it from binding the operator. D) The product binds to the biosynthetic enzymes, blocking them directly.
31) A protein that initiates gene transcription and allows for non-glucose molecules to be used is A) operon. B) repressor. C) promoter. D) operator. E) CAP.
32)
The proteins necessary for the use of lactose in E. coli are collectively called the
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A) lac regulator. B) lac suppressor. C) lac operon. D) lac promoter. E) lac transcriptional operator.
33) If a strain of bacteria had a mutation that blocked expression of the lac repressor, what would you expect as a result? A) The mutant strain would outcompete wildype strains, since it could always utilize lactose. B) The mutant strain would grow at the same rate as wildtype if lactose was not present. C) The mutant strain would waste energy producing enzymes in the absence of lactose. D) The mutant strain would act the same, because it would still require lac activator protein to turn on.
34) When E. coli cells produce the amino acid tryptophan, a cluster of five genes is transcribed together. This cluster of genes is referred to as the A) trp transcriptional operator. B) trp regulator. C) trp suppressor. D) trp operon. E) trp promoter.
35) If you were given a bacterial strain with a mutation in the promoter region of the trp operon the most likely effect would be A) interference with RNA polymerase binding. B) to block the repressor from binding. C) derepression of the trp operon. D) enabling the trp operon to be expressed in the absence of tryptophan. E) lack of expression of just the first gene in the operon.
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36)
Transcriptional control-proteins increase the rate of transcription by binding to A) mRNA sequences within the DNA. B) tRNA sequences within the DNA. C) operator sequences within the DNA. D) promoter sequences within the DNA. E) enhancer sequences within the DNA.
37)
Enhancers are the binding sites for the A) promoters of DNA synthesis. B) suppressorfactors. C) coactivation factors. D) mediator factors. E) specific transcription factors.
38)
In eukaryotes, specific transcription factors have two distinct domains: A) a DNA-binding domain and a RNA-binding domain. B) a DNA-binding domain and an activation domain. C) a DNA-binding domain and a repressor domain. D) a DNA-binding domain and an enhancer domain. E) a DNA-binding domain and an operator domain.
39) Your research project involves the characterization of a recently identified transcription factor. As part of your project, you want to determine if this transcription factor binds directly to any of the general transcription factors. Unfortunately, you are having trouble expressing the full-length protein. What approach may help achieve your research goal?
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A) You must find a way to express the full-length protein, since transcription factor functions do not lie in separate domains. B) Identify the RNA that mediates the protein-protein binding. C) Express and purify only the DNA-binding domain, and test for binding. D) Express and purify only the activation domain, and test for binding.
40) The progesterone receptor (PR) is a steroid hormone receptor and transcription factor. The protein SRC-1, which does not bind DNA by itself, can bind to PR and increase expression of genes regulated by PR. Based on this information, SRC-1 is best described as a(n) A) coactivator. B) inducer. C) general transcription factor. D) specific transcription factor.
41)
The TFIID complex is formed by A) TATA-binding protein TBP and TAFs. B) TATA-binding protein TBP, TAFs and RNA pol II. C) TAFs and the core promoter. D) TATA-binding protein and activators.
42) Many factors bind around the core promoter to form the eukaryotic initation complex, but the most important one is _________blank, which directly binds the TATA box. A) TFIIA B) TFIIB C) TFIID D) TFIIE E) TFIIF F) TFIIH G) TAF
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43) is
You are working to identify enhancer regions of a particular gene. The best place to look
A) immediately upstream of the promoter. B) immediately downstream of the promoter. C) primarily upstream of the promoter, possibly some distance away. D) primarily downstream of the promoter, including the exons of the coding region.
44) You are studying the effects of specific transcription factors on the activation of gene expression. You notice that one particular transcription factor binds far away from the promoter of its target gene. What can explain this? A) The transcription factor transcribes small RNAs that then bind to the promoter and activate the gene's expression. B) The transcription factor tags the enhancer with ubiquitin to stimulate transcription. C) DNA looping brings the transcription factor closer to the promoter and initiates gene transcription. D) RNA looping brings the transcription factor closer to the promoter and initiates gene transcription.
45) Vertebrate cells possess a protein that binds to clusters of 5-methylcytosine and ensures the gene will stay in the "off" position. This control of gene regulation is a result of A) translation. B) enhancer expression. C) methylation. D) promoter expression. E) operator suppression.
46)
Histones that are tightly wound by DNA and are the basic unit of chromatin are called
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A) operons. B) nucleosomes. C) proteinclusters. D) repressorgenes. E) facilitatorssites.
47)
Within its core a nucleosome contains_________blank histones. A) 2 B) 4 C) 6 D) 8 E) 64
48) In vertebrates, DNA methylation - the addition of a methyl group to DNA nucleotides ensures that A) the gene functions without interruption. B) no errors will be made during transcription. C) the nucleosome will quickly form, which assists in mRNA formation. D) once that gene is transcribed, the mRNA is saved and used over and over again. E) once a gene is turned off, it will remain off.
49)
DNA methylation is the only known natural modification of DNA. It affects A) adenine bases. B) guanine bases. C) cytosine bases. D) thymine bases.
50)
Elucidation of the histone code might
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A) allow us to turn specific genes on or off. B) allow the determination of nucleosome composition. C) lead to chromatin remodeling. D) allow us to control translation.
51) If you were able to look very closely at a portion of DNA and find methylated histones, you would A) be mistaken since only DNA can be methylated, not histones. B) be looking at a region of active chromatin. C) be looking at a region of inactive chromatin. D) be looking at a chromatin remodeling complex.
52) The p300/CBP (CREB-binding protein) proteins are histone acetyltransferases that help regulate the transcription of many genes. Based on this information you can conclude that these proteins A) acetylate purines. B) remodel chromatin. C) recruit helicases. D) physically connect activator proteins.
53) You work for a pharmaceutical company that designs small RNAs, used to control expression of disease genes. The primary focus area of your research should be A) transcriptionalrepression. B) transcriptionalactivation. C) translationalrepression. D) translationalactivation.
54) Although the specific mechanism of RNA interference has not been fully defined, it involves
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A) double stranded RNA interference with mRNA. B) double stranded RNA interference with DNA. C) double stranded DNA interference with mRNA. D) double stranded mRNA interference with DNA.
55) Small RNAs can regulate gene expression. One type, called micro RNA (miRNA), acts by binding directly to A) mRNA to prevent translation. B) tRNA to prevent transcription. C) mRNA to prevent transcription. D) tRNA to prevent translation.
56)
The enzyme dicer chops dsRNA molecules into small pieces of A) mRNA and miRNA. B) miRNA and siRNA. C) siRNA and rRNA. D) mRNA and siRNA.
57)
The primary transcripts in eukaryotes are most accurately described as A) composed of RNApolymerase and associated histones. B) having the exonsremoved and the introns retained for translation. C) a faithful copyof the entire gene including exons and introns. D) anexact copy of the gene, but the introns have been removed. E) an RNA copy, but the noncoding exons and introns have been removed.
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58) You are studying the function of a recently identified gene in C. elegans. You perform genetic screens for several months in an attempt to isolate loss-of-function gene mutations, but your efforts are unsuccessful. Your advisor suggests you try another approach to eliminate gene function. The best technique to accomplish this goal would be A) to design arepressor to bind to the operon of this gene. B) use a histonedeacetylase to induce a transcriptionally inactive state. C) use a C. elegans strain with a homozygous TFIID mutation toprevent the translation initiation complex from forming. D) use RNAinterference to prevent mRNA translation.
59)
Eukaryotic cell mRNA transcripts can remain in the cell for hours because they are A) stable. B) long. C) isolated. D) analogous.
60) The gene encoding apolipoprotein B exists in two isoforms, APOB100 and APOB48. These two forms are produced as a result of A) tissue-specific expression. B) a gene mutation that results in a stop codon. C) RNA editing. D) alternative splicing.
61) Production of the iron-storing protein ferritin is regulated by aconitase, which binds to a 30-nucleotide sequence at the beginning of the ferritin mRNA and interferes with ribosome binding. Aconitase must be a
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A) transcription repressor protein. B) translation repressor protein. C) RNA interference protein. D) translation initiation protein.
62)
What is the difference between a gene that is derepressed and one that is induced?
A) Genes that are derepressed are turned on because an inducer molecule is present. By comparison, a gene that is induced is turned on because a repressor protein is bound to the operator. B) A derepressed gene is turned off and an induced gene is activated to be expressed. C) A gene that is derepressed is turned on because a repressor protein is not bound without its cofactor. By comparison, a gene that is induced is turned on because an inducer molecule prevents binding of the repressor. D) There is no difference between a gene that is derepressed and one that is induced.
63) In your research, you have discovered that Protein X is often ubiquitinated in people with a certain disease. What would you predict about levels of Protein X in these patients? A) Levels of Protein X will be low due to degradation in the proteasome. B) Levels of Protein X will be the same, just carrying a ubiquitin tag. C) Levels of Protein X will be increased due to transcriptional activation. D) Levels of Protein X will be decreased due to negative feedback on transcription. E) Levels of Protein X will be increased due to protection from degradation.
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Answer Key Test name: Chap 16_13e_Raven 1) [A, B, D] 2) [A, C, D] 3) [A, B, E] 4) [A, C, D] 5) [A, B, D] 6) [A, C, E] 7) B 8) A 9) B 10) C 11) C 12) D 13) B 14) C 15) B 16) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses gene regulation in bacteria. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o Regulation of a gene refers to the control of its expression. o A novel gene is a new gene – that is, one that has not been wellstudied or understood. o Bacteria are prokaryotes like E. coli or Salmonella. Their gene regulation is similar to eukaryotes, but has distinct features. Gather Content • What do you already know about gene regulation in bacteria? o Gene regulation in bacteria is similar to that of eukaryotes. o However, bacteria do not have a nucleus, therefore there is less separation between transcription and translation. o Because of this, bacteria tend to rely on transcriptional regulation more than translational or post-translational regulation. Consider Possibilities • Consider the different answer options. Which can you rule out? o Is a prokaryotic gene likely to use alternative splicing regulation? No, prokaryotic genes don’t have introns, and don’t have splicing machinery. o Is a prokaryotic gene likely to use regulation by enhancer elements? No, prokaryotic genes don’t have distant enhancers like eukaryotic genes do. o Is a prokaryotic gene likely to use regulation by general transcription Version 1
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factors? No, this term is used for eukaryotes to differentiate the basal transcriptional machinery from more specific transcriptional regulatory proteins. Moreover, the general transcription factors do not play an important role in regulation. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Is a prokaryotic gene likely to use translational regulation? No. Since bacteria lack a nuclear membrane, transcription and translation are coupled. o Thus it is important that they regulate gene expression at the transcriptional level. o Transcriptional regulation is the most common mode of gene regulation in bacteria. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked about the most common type of regulation in bacteria. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that transcriptional regulation is by far the most common type of regulation in bacteria? o Did you remember that bacteria lack splicing and lack enhancers? 17) A 18) E Version 1
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19) B
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Clarify Question • What is the key concept addressed by the question? o This question addresses transcriptional regulatory proteins. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o Synthetic DNA is an artificially designed and produced piece of DNA. o A DNA motif is a specific sequence that is recognizable by DNAbinding proteins. o Transcriptional regulatory proteins, also called transcription factors, are proteins that bind DNA to regulate transcription. Gather Content • What do you already know about transcriptional regulatory proteins? o Transcriptional regulatory proteins are proteins that bind DNA to control when, where, and how much a gene is transcribed. o These proteins have special DNA-binding domains, such as the helixturn-helix or the zinc finger domain. Consider Possibilities • Consider the different answer options. Which can you rule out? o For a protein to bind a specific DNA motif, can it recognize the phosphate backbone? No, because that will be identical on every piece of DNA. o Can it recognize the sugar backbone? No, because that will be identical on every piece of DNA. o Can it recognize the open hydrogen bonds of single-stranded DNA? Version 1
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No, because the DNA is double stranded before transcription begins. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o So, it makes sense that the regulatory protein is going to need to recognize the unique sequence of bases while the DNA is doublestranded. o In fact, regulatory proteins bind DNA in the major groove and not the minor groove, because it gives enough room for the protein to bind along the bases. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what part of the DNA is use for motif recognition by regulatory proteins. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that regulatory proteins must recognize the unique parts of the DNA – i.e., the sequence of bases? o Did you realize that the proteins bind the major groove because the minor groove is not wide enough? 20) A 21) D 22) E 23) B
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Clarify Question • What is the key concept addressed by the question? o This question addresses the function of operators and repressors. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o An operator is a site on the DNA that can attract a repressor protein to block transcription. Gather Content • What do you already know about operators and repressors? o Repressors are proteins that bind to regulatory sites on DNA called operators to prevent or decrease the initiation of transcription. They act as a kind of roadblock to prevent the polymerase from initiating effectively. Consider Possibilities • What other information is related to the question? Which information is most useful? o When we learned about the lac repressor, we learned that it binds the operator site just downstream of the promoter. When the repressor protein is bound, it blocks RNA polymerase and prevents transcription. o Likewise, when we learned about the trp repressor, we learned that it binds the operator site just downstream of the promoter. When the repressor protein is bound, it blocks RNA polymerase and prevents transcription. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Operator sites are located just downstream of the promoter, because when the repressor protein binds, it acts like a roadblock to prevent transcription by RNA polymerase. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked where an operator site is typically located to block transcription. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that operator sites lie downstream of the promoter, so that when the repressor binds it acts like a roadblock? 24) B 25) A 26) D 27) C 28) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses prokaryotic transcriptional regulation. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o Beta-galactosidase is an enzyme that processes lactose. o Lactose and galactose are two sugars. Lactose is a disaccharide; galactose is a monosaccharide. o A carbon source is a molecule that is used like a building block to produce another organic molecule. Gather Content • What do you already know about prokaryotic transcriptional regulation? o We have seen several examples of prokaryotic transcriptional regulation. o For instance, we learned that the lac operon is activated in the presence of lactose. Lactose binds to the repressor protein, blocking it from preventing transcription. In this way, lactose “induces” transcription. Consider Possibilities • Consider the different answer options. Which can you rule out? o Can we call the lactose in this case a repressor? No, because its role is to activate transcription. (This is true even if it technically acts by repressing a repressor.) o Can we call the lactose in this case an operon? No, an operon is a set Version 1
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of genes in the DNA, under coordinated transcriptional control. The lactose is a small sugar, not DNA. o Can we call the lactose in this case a DNA-binding protein? No, because the lactose is a sugar, not a protein. Also it does not directly bind the DNA – it likely binds to a DNA-binding protein as a cofactor. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o When a small molecule induces gene expression by interacting as a cofactor with a protein, we can call the molecule an “inducer”. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what term you would use to describe lactose when it acts to turn on gene expression. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that lactose must bind to a regulatory protein to activate gene expression? o Did you remember that that type of molecule is called an inducer? 29) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses prokaryotic transcriptional regulation. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o Beta-galactosidase is an enzyme that processes lactose. o A lactose analog is a small molecule very similar to lactose. Lactose is a disaccharide— that is, a two-ring sugar. o A substrate is a molecule that an enzyme acts upon, usually changing it to another molecule. Gather Content • What do you already know about prokaryotic transcriptional regulation? o We have seen several examples of prokaryotic transcriptional regulation. o For instance, we learned that the lac operon is activated in the presence of lactose. Lactose binds to the repressor protein, blocking it from preventing transcription. In this way, lactose “induces” transcription. Consider Possibilities • Consider the different answer options. Which can you rule out? o Can we call the IPTG in this case a repressor? No, because its role is to activate transcription. (This is true even if it technically acts by repressing a repressor.) o Can we call the IPTG in this case an operon? No, an operon is a set of Version 1
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genes in the DNA, under coordinated transcriptional control. The IPTG is a small sugar, not DNA. o Can we call the IPTG in this case a DNA-binding protein? No, because the IPTG is a sugar, not a protein. Also it does not directly bind the DNA – it binds to the DNA-binding repressor protein as a cofactor. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o When a small molecule induces gene expression by interacting as a cofactor with a protein, we can call the molecule an “inducer”. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what term you would use to describe IPTG when it acts to turn on gene expression. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that IPTG binds to a regulatory protein to activate gene expression? o Did you remember that that type of molecule is called an inducer? 30) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses transcriptional regulation. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o A prokaryotic operon is a small set of adjacent genes in a bacterium that are expressed together, and usually work in the same pathway. o The biosynthetic product from a pathway would be the small molecule that the encoded enzymes produce as a product. Gather Content • What do you already know about transcriptional regulation in prokaryotes? o We learned about three examples of regulation in prokaryotes: lactose regulation of the lac operon, glucose regulation of the lac operon, and tryptophan’s regulation of the trp operon. o This example is similar to the regulation of the trp operon by tryptophan. It is an example of negative feedback by the biosynthetic product. o When the product is low, operon expression is high. When the product is high, operon expression is low. Consider Possibilities • Consider the different answer options. Which can you rule out? o Could this operon be regulated by the product binding an activator, helping RNA polymerase to bind the promoter? No, because then high product levels would have high expression, low product levels would Version 1
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have low expression. o Could this operon be regulated by the product binding a repressor, preventing it from binding the operator? No, because again, in that case high product levels would have high expression, low product levels would have low expression. o Could this operon be regulated by the product binding to the biosynthetic enzymes, blocking them directly? That would be negative feedback, but it would not affect the expression of the operon – in other words, the levels of mRNA produced for the enzyme genes. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Could this operon be regulated by the product binding a repressor, allowing it to bind the operator? Yes. This would mean that low product levels would derepress the operon, allowing higher expression. o This is similar to the regulation of the trp operon. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what is the likely mode of regulation for an operon that is controlled by negative feedback from its enzymes’ biosynthetic product. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that this is similar to the regulation of the trp operon by tryptophan? Version 1
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o Did you realize that high levels of the product probably block expression by helping a repressor to block transcription? o Was there an alternative explanation not listed as an option here? 31) E 32) C 33) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses regulation of the lac operon. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o The lac repressor is a protein that binds the operator site to regulate transcription of the lac operon. Gather Content • What do you already know about the lac operon? o The lac operon encodes proteins that help the cell use lactose as an energy source. o The operon is only transcribed when lactose is present. o When present, lactose binds the repressor protein and keeps it from binding the operator site. That allows transcription to occur. Consider Possibilities • Consider the different answer options. Which can you rule out? o Would the mutant strain outcompete wildype strains, since it could always utilize lactose? No, because lactose is not always present, and it would waste energy synthesizing useless enzymes. o Would the mutant strain would grow at the same rate as wildtype if lactose was not present? No, because it would waste energy synthesizing useless enzymes. o Would the mutant strain would act the same, because it would still require lac activator protein to turn on? No. In fact there is no “ lac activator” protein. The lac operon is controlled by the activity of the lac Version 1
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repressor. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Unless lactose was always present at high levels, the mutant strain would be harmed by this mutation. It would waste energy producing useless enzymes that were not needed. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what would result for a bacterium mutant for the lac repressor. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you remember that the lac operon encodes proteins that help the cell to utilize lactose? o Did you recognize that the lac operon is regulated so that the cell doesn’t waste energy unless lactose is present? 34) D 35) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses the promoter. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o The promoter region is the region of a gene where the RNA polymerase binds and initiates transcription. o The trp operon is a set of genes in bacteria that are transcribed together to produce enzymes for the biosynthesis of tryptophan. Gather Content • What do you already know about promoters? o A promoter is a region at the beginning of a gene, in the -35 and -10 region, that attracts the binding of RNA polymerase to initiate transcription. Consider Possibilities • Consider the different answer options. Which can you rule out? o If the promoter was mutated, would this prevent the repressor from binding? No, because the repressor binds the operator, which is downstream of the promoter. o Would this cause derepression of the trp operon? In other words, prevent repression to allow expression? No, because repression depends on the repressor binding the operator, not the promoter. o Would this enable the trp operon to be expressed in the absence of tryptophan? No, because that would require preventing the function of the repressor, which binds the operator. Version 1
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o Would this cause lack of expression of just the first gene in the operon? No, because the promoter is necessary for expression of all the genes in the operon. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o What is the role of the promoter region? To allow RNA polymerase to bind and initiate transcription. o What binds to the promoter region? RNA polymerase. o So if the promoter was mutated, RNA polymerase would likely fail to bind and fail to initiate transcription. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what would result from a mutation in the promoter of the trp operon. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that the promoter is necessary for the binding of RNA polymerase? o Did you remember that the repressor acts on the operator region, not the promoter? 36) E 37) E 38) B 39) D Version 1
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Clarify Question • What is the key concept addressed by the question? o This question addresses the structure of specific transcription factors. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o A recently identified transcription factor must refer to a specific transcription factor, since the general transcription factors have been well described. o The general transcription factors are the set of transcription factors that underlie transcription in all genes. By themselves, they can only support transcription at some low, basal rate. o In this question, e xpressing a protein refers to the process of cloning the gene into bacteria to produce large amounts of the protein product. Gather Content • What do you already know about specific transcription factors? o Specific transcription factors constitute a huge variety of proteins that act in conjunction with the general transcription factors to increase transcription of specific genes in certain cells and times. o They typically have two separate domains: a DNA-binding domain that binds specific DNA sequence motifs, and an activating domain that interacts with the general transcription factors to stimulate transcription. Consider Possibilities • What other information is related to the question? Which information is most useful?
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• Consider the different answer options. Which can you rule out? o To answer your research question, must you find a way to express the full-length protein, since transcription factor functions do not lie in separate domains? No, this is not correct. Typically the DNA-binding and activation domains are separable. o Should you identify the RNA that mediates the protein-protein binding? No, because typically there is no RNA – the specific transcription factor binds the general TFs directly. o Should you express and purify only the DNA-binding domain, and test for binding? No, because that wasn’t the question you wanted to answer. You need to know how it binds the general TF proteins, not the DNA sequence. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o To answer your research question, should you express and purify only the activation domain, and test for binding? Yes, this strategy may very well work! It may be easier to express the shorter protein, and you can use the domain to test for protein binding to the general transcription factors. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what approach could help to determine binding between a specific transcription factor and the general transcription factors. Version 1
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o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that the DNA-binding and activation functions use separate protein domains? 40) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses coactivators. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o A s teroid hormone receptor is a special kind of transcription factor. They respond to hormones, then enter the nucleus and regulate transcription. Gather Content • What do you already know about coactivators? o In our text, coactivators are described as transcription factors that stabilize the transcription complex by bridging activator proteins with the complex. They act by binding the transcription factor and then binding to another part of the transcription apparatus. Consider Possibilities • Consider the different answer options. Which can you rule out? o Is SRC-1 best described as a general transcription factor? No, because it does not act in the transcription of every gene. o Is SRC-1 best described as an inducer? No. Our text gave us several examples of inducers. All of them were small molecules in prokaryotes that activate genes by inhibiting the binding of a repressor protein. o Is SRC-1 best described as a specific transcription factor? Perhaps – but its role is to enhance the stimulation by another specific transcription factor, the progesterone receptor.
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o SRC-1 is best described as a coactivator – a protein that acts to enhance the activity of other specific transcription factors, by bridging activator proteins with the complex. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what is the best description of the protein SRC-1. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that as a “helper” for another specific transcription factor, SRC-1 is best described as a coactivator? 41) A 42) C 43) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses enhancers. • What type of thinking is required? o This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. • What key words does the question contain and what do they mean? o Enhancer regions are elements in the DNA sequence that contain binding sites for specific transcription factors to regulate transcription. Gather Content • What do you already know about enhancers? o Enhancers are DNA sequences necessary for high levels of transcription that can act independently of position or orientation. o The ability of enhancers to act over large distances is thought to be accomplished by DNA bending to form a loop, positioning the enhancer closer to the promoter. Consider Possibilities • What other information is related to the question? Which information is most useful? o There is a lot of variability in the placement of enhancers. But what is the general rule of thumb? Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Generally enhancers are most likely to lie upstream of the promoter, Version 1
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and they can be close or surprisingly far away. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what is the best place to look for enhancer elements for a gene. o The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. o Did you remember that enhancers are usually upstream of the promoter? o Did you remember that enhancers can be a long distance away, due to DNA looping? 44) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses transcriptional regulation. • What type of thinking is required? o This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. • What key words does the question contain and what do they mean? o Transcription factors are proteins that regulate transcription of their target genes. o The promoter is the region of the gene just upstream from the transcription start site. Gather Content • What do you already know about transcriptional regulation? o Transcription is regulated in eukaryotes by transcription factors. o Specific transcription factors can bind at the promoter, or at more distant enhancer sites. Consider Possibilities • Consider the different answer options. Which can you rule out? o Is it likely that the transcription factor transcribes small RNAs that then bind to the promoter and activate the gene's expression? No, because small RNAs would typically inhibit gene expression. o Is it likely that the transcription factor tags the enhancer with ubiquitin to stimulate transcription? No, because only proteins are tagged with ubiquitin, to target them for proteolysis. o Is it likely that RNA looping brings the transcription factor closer to the promoter and initiates gene transcription? No, because the premRNA is not involved. Version 1
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Is it likely that DNA looping brings the transcription factor closer to the promoter and initiates gene transcription? Yes! This is how distant enhancers are thought to work. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked why a transcription factor might bind far from its target gene’s promoter. o The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. o Did you recognize that the transcription factor is likely binding an enhancer? o Did you know that distant enhancers are thought to work by the looping of the DNA? 45) C 46) B 47) D 48) E 49) C 50) A 51) C 52) B
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Clarify Question • What is the key concept addressed by the question? o This question addresses histone acetyltransferases. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o Histone acetyltransferases are enzymes that acetylate (that is, add a COCH3 group) to histone proteins. Gather Content • What do you already know about histone acetyltransferases? o Histones are proteins that form much of the structure of chromatin – that is, the DNA and proteins of the chromosome. Consider Possibilities • Consider the different answer options. Which can you rule out? o Would histone acetyltransferases act to acetylate purines? No, they acetylate histone proteins, not the DNA itself. o Would they act to recruit helicases? No, they change the structure of chromatin by modifying histones. o Would they act to physically connect activator proteins? No. Although sometimes called coactivators, they activate by modifying chromatin structure, not directly connecting transcription factors. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o Would histone acetyltransferases act to remodel chromatin? Yes! That is their mode of action. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked about the role of p300/CBP proteins. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that histone acetyltransferases modify chromatin structure? 53) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses small RNAs. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o A pharmaceutical company is a company that designs new medicinal drugs. o Small RNAs are either naturally-occuring or manufactured RNAs such as micro-RNAs (miRNAs) or small interfering RNAs (siRNAs) that regulate gene expression. Gather Content • What do you already know about small RNAs? o Small RNAs are used naturally by organisms, and also by researchers, to silence genes. Consider Possibilities • What other information is related to the question? Which information is most useful? o Small RNAs typically work by silencing genes – that is, repressing gene expression. o Their mechanism of action involves binding of the small RNA to the native mRNA, attracting enzymes that inhibit translation or cut up the mRNA. Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Since small RNAs act on the native mRNA, their regulation is posttranscriptional (after transcription), and specifically translational regulation. o Since they inhibit the expression of genes, they act as translational repressors. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what type of regulation you should focus on if you want to cure disease with small RNAs. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that small RNAs typically work posttranscriptionally, binding with mRNA to block translation? o Did you consider what RNAs are most likely to be able to bind? 54) A 55) A 56) B 57) C 58) D
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Clarify Question • What is the key concept addressed by the question? o This question addresses loss-of-function mutations. • What type of thinking is required? o This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. • What key words does the question contain and what do they mean? o A loss-of-function gene mutation is a mutation that “breaks” the gene, preventing it from working. Gather Content • What do you already know about loss-of-function mutations? o Loss-of-function mutations are any mutation that results in less of the normal gene activity. o They may be due to total deletion of the gene, or a lower level of expression of the mRNA, or because the protein cannot work at the normal rate. Consider Possibilities • Consider the different answer options. Which can you rule out? o To mimic a loss-of-function mutation in this gene, should you design a repressor to bind to the operon of this gene? Bad idea. First of all, eukaryotes like C. elegans don’t have operons. Second, even if they did that would knock out several genes at once. Third, that would be very difficult to do. o Should you use a histone deacetylase to induce a transcriptionally inactive state? No, that would probably inactivate many many genes and kill the worms. o Should you use a C. elegans strain with a homozygous TFIID Version 1
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mutation to prevent the translation initiation complex from forming? No, that would definitely affect all the genes and kill the worm. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o To mimic a loss-of-function mutation in this gene, should you use RNA interference to prevent mRNA translation? Yes! That is an excellent way to quickly mimic a loss-of-function mutation in one specific gene. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what approach would be a good substitute for finding a mutation in a gene. o The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. o Did you recognize that RNAi is a technique that allows a researcher to mimic a loss-of-function mutation? 59) A 60) C 61) B
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Clarify Question • What is the key concept addressed by the question? o This question addresses translational regulation. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o Ferritin is the gene whose expression is regulated in this question. o Aconitase is the regulator protein. o The ribosome is the complex which carries out translation. Gather Content • What do you already know about translational regulation? o Translational regulation controls gene expression by regulating the amount of protein produced. Consider Possibilities • Consider the different answer options. Which can you rule out? o Since aconitase binds the mRNA to block ribosome binding, does that make it a transcription repressor protein? No, because the ribosome is involved in translation. o Does that make it an RNA interference protein? No, RNAi works by small RNA binding the mRNA sequence, leading to cleavage of the mRNA. o Does that make it a translation initiation protein? No, because in this case it is blocking translation. Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Since aconitase binds the mRNA to block ribosome binding, does that make it a translation repressor protein? Yes! Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to describe the role of aconitase in the regulation of ferritin. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that since aconitase blocks ribosome binding to the mRNA, it must be a repressor of translation? 62) C 63) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses ubiquitination. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o Ubiquitinated proteins carry a ubiquitin tag. Gather Content • What do you already know about ubiquitination? o Proteins are ubiquitinated to mark them for degradation. Consider Possibilities • What other information is related to the question? Which information is most useful? o Eukaryotic cells selectively degrade proteins when they are no longer needed, by marking them. o The mark that cells use is the attachment of a ubiquitin molecule. Ubiquitin is a 76–amino-acid protein that can exist as an isolated molecule or in longer chains that are attached to other proteins. o The process of ubiquitination followed by degradation by the proteasome is called the ubiquitin–proteasome pathway. As the proteins are degraded, the ubiquitin chain itself is simply cleaved back into ubiquitin units that can then be reused. Choose Answer • Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer? o If a certain protein is abnormally tagged with ubiquitin, then its levels will greatly decrease since it will be degraded in the proteasome. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what would happen to levels of a protein that is ubiquitinated. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you remember that ubiquitin is a tag that marks a protein for destruction via the proteasome?
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Chapter 17 13e CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 1) Which components are required in plasmids? (Select all that apply) A) A selectable marker, usually antibiotic resistance B) A bacterial artificial chromosome C) One or more unique restriction sites where foreign DNA can be added D) An origin of replication to allow it to replicate in E. coli independently of the host chromosome
2) You digest DNA from the frog Xenopus laevis with the enzyme NotI that produces sticky DNA ends. You can ligate your DNA to _________blank. (Select all that apply) A) blunt AluI ends from Xenopus laevis B) sticky NotI ends from Xenopus laevis C) blunt AluI ends from bacteria D) sticky NotI ends from bacteria E) sticky EcoRI ends from Xenopus laevis F) sticky EcoRI ends from bacteria
3) A gel electrophoresis is performed, but when the gel imager is used, no bands appear. The researcher might have forgotten to _________blank. (Select all that apply) A) add electric current B) add antibody C) ligate the DNA fragments together D) include DNA dye E) include an RNA probe
4)
Both DNA replication and PCR require: (Select all that apply)
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A) DNA polymerase. B) DNA helicase. C) a DNA template. D) a thermocycler machine. E) plasmid DNA.
5) Select the experiments that can be characterized as reverse genetics: (Select all that apply) A) Generation andanalysis of a knockout mouse B) Random mutagenesisof an organism, then selecting mutants by phenotype C) RNA interference of a gene in C. elegans D) Using reversetranscriptase to create a cDNA library
6) Your city is considering a proposal to build a new algae-based biofuel plant. What benefits would this have over traditional fossil fuels? (Select all that apply) A) The kelp fronds would provide habitat for endangered sea otters. B) It contributes less carbon to the atmosphere overall. C) It is a renewable resource. D) Biofuel doesn’t need to be burned to provide energy. E) The system could be paired with wastewater treatment. F) The algae can be filtered from the water and used for fuel without refinement.
7)
Which genes were incorporated into the genome of Golden Rice? (Select all that apply) A) Daffodil phytoenesynthase gene B) Bacterial carotenedesaturase gene C) Bacterialbeta-galactosidase D) Daffodil lycopenebeta-cyclase gene
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MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 8) The most recent techniques developed in the biological sciences allow the manipulation of DNA with the ultimate goal of intervening directly with the_________blank fate of organisms. A) genetic B) developmental C) adult D) mitotic
9)
Small circular, extrachromosomal DNA segments are known as_________blank. A) vectors B) plasmids C) clones D) RNA
10)
Enzymes that cleave DNA at specific sites are called_________blank . A) vectors B) peptidases C) restriction endonucleases D) DNAses
11) Single-stranded complementary tails that are produced by restriction digestion are called ______ ends. A) sticky B) orphaned C) vectors D) 5'
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12) Bacterial plasmids and artificial chromosomes are used as_________blank to insert foreign DNA into host cells and create recombinant genomes. A) clones B) vectors C) endonucleases D) subunits
13) You want to insert your favorite gene, which has been digested with Ncol endonuclease on both ends, into a vector. Ncol recognizes the DNA sequence C*CATGG. The vector you want to use contains many endonuclease recognition sites, but does not include an Ncol site. Which restriction endonuclease would be the most suitable replacement to digest the vector? A) Sphl - G*CATGC B) Sunl - C*GTACG C) Kpnl - GGTAC*C D) CViAll - C*ATG
14) Single-stranded ends generated by the same restriction enzyme are complementary to each other. They can be joined together A) even when the source of the DNA is different. B) only when the source of the DNA is the same. C) but the "sticky ends" will most likely have to be modified. D) but the hybridization of the two ends may cause a problem with cloning. E) only if the subunits have been methylated.
15) a(n)
Two strands of DNA that have been cut by an endonuclease can be sealed together by
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A) polymerase enzyme. B) ligase enzyme. C) exonuclease enzyme. D) protease enzyme. E) methylase enzyme.
16)
Restriction enzymes are A) proteases. B) lipases. C) endonucleases. D) exonucleases.
17)
Identify a sequence that is most likely to be recognized by a restriction enzyme. A) CGATGC B) CCCTTT C) TGGCCA D) TCATCA
18) BamHI is a Type II restriction enzyme that recognizes the sequence 5' G*GATCC 3', and cuts between the two Gs, leaving a 5' overhang. If you were to digest DNA with BamHI, what would be the sequence of the overhanging sticky ends of the two strands? A) 5' GATCC 3' and 5' GATCC 3' B) 5' GATCC 3' and 5' GGATC 3' C) 5' GATC 3' and 5' GATC 3' D) 5' GATC 3' and 5' CTAG 3' E) 5' G 3' and 5' G 3' F) 5' G 3' and 5' C 3'
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19) Which of the following types of information would be most useful in an effort to move a DNA fragment from one plasmid vector to another, using molecular cloning techniques? A) DNA fingerprint data B) Sequence of PCR primers C) Data from cloning of Dolly the sheep D) Restriction maps of the plasmids
20) A fourth type of restriction enzyme is identified that cleaves at precise locations like a type II enzyme, but it also occasionally makes mistakes and cuts elsewhere. Would this type of enzyme be a useful enzyme to use in molecular cloning? A) Yes, because it cuts correctly sometimes. B) No, because it is a precise enzyme. C) No, because cutting mistakes could lead to incorrect cloning. D) Yes, because cutting mistakes don't matter in molecular cloning.
21) A 6.85 kb EcoRI fragment of DNA is shown below. The location of several restriction sites is indicated. Scale is approximate.
©McGraw-Hill Education
If you were to completely digest this fragment of DNA with PstI, how many pieces of DNA would you obtain?
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A) 1 B) 2 C) 3 D) 4
22) A 6.85 kb EcoRI fragment of DNA is shown below. The location of several restriction sites is indicated. Scale is approximate.
©McGraw-Hill Education If you were to digest this DNA with PstI, which length of DNA fragment would migrate the fastest on an agarose gel? A) 803 B) 2622 C) 3425 D) 235
23) Gel_________blank is a process that separates DNA or protein fragments according to their size, by causing them to migrate within a gel in response to an electric field. A) duplication B) blotting C) electrophoresis D) migration
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24)
All of the following involve molecular biology techniques except A) ligating DNA fragments together. B) using restriction enzymes to cut specific sequences of DNA. C) using a DNA polymerase to copy DNA via PCR. D) creation of Okazaki fragments.
25)
An enzyme that has been isolated from retroviruses and is used to generate cDNA is A) transverse ligase. B) reverse transcriptase. C) reverse endonuclease. D) recombinant RNase. E) RNA polymerase.
26)
The most common way to follow bacterial transformation with a plasmid is by A) manufacturing the bacterial protein. B) conferring antibiotic resistance. C) separating the altered cell surface. D) making the cells immortal. E) altering the physical appearance of the cells.
27)
Which of the following two enzymes are needed to construct a cDNA library? A) Reverse transcriptase and DNA ligase B) Reverse transcriptase and Taq polymerase C) DNA ligase and Taq polymerase D) Taq polymerase and RNA polymerase
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28) Investigators have found a new species of bacteria that lives under both aerobic and anaerobic conditions. They hypothesize that different genes are expressed in each condition. Which experiment could test this hypothesis and identify important genes? A) Completely sequence the genome of the bacteria in both aerobic and anaerobic conditions B) Collect mRNA from both anaerobic and aerobic conditions and generate two cDNA libraries C) Measure levels of RNA polymerase in both conditions D) Design primers to a specific region of the genome and sequence this region during both anaerobic and aerobic conditions
29) The PCR technique requires a DNA polymerase from an organism that can endure high heat, such as Thermus aquaticus. Which step of the protocol makes the heat-stability most necessary? A) Synthesis B) Primer annealing C) Denaturation D) Antibody binding
30)
A technique used to amplify a desired piece of DNA is A) gel electrophoresis. B) RFLP. C) PCR. D) plasmid replication. E) Northern Blot.
31) You have discovered a very small amount of DNA from an ancient organism that you want to save and study. What is the very first thing you should do to allow you to study this DNA in the lab?
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A) RT-PCR B) Gel electrophoresis C) Polymerase chain reaction (PCR) D) Insert the DNA into a vector
32) Three scientists are using different forms of PCR for their research. Abby wants to determine changes in gene expression levels in a tissue, so she uses _________blank. Bob is trying to extract genetic information from a wooly mammoth fossil, so he uses _________blank. Chris needs to express a gene in bacteria that matches the form expressed in kidney cells, so she uses _________blank. A) quantitative RT-PCR; PCR; RT-PCR B) PCR; quantitative RT-PCR; RT-PCR C) RT-PCR; PCR; quantitative RT-PCR D) RT-PCR; quantitative RT-PCR; PCR E) quantitative RT-PCR; RT-PCR; PCR
33) You are the scientific consultant for a television show about forensic analysis. In an upcoming episode, investigators will compare the DNA of a suspect and a DNA sample collected from the victim’s fingernails. You are to write up a brief explanation of the technique required for comparing the DNA. Which technique should you explain? A) DNA fingerprinting B) Fluorescent in situ hybridization C) RNAi D) RT-PCR
34) Prior to using PCR to introduce mutations into DNAin vitro, what was a common method of mutagenesis used by scientists?
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A) Self-fertilization of plants or inbreeding of animal models B) Chemicals to induce mutations C) Physical manipulation of DNA (e.g. vortexing) D) Using only old parents to set crosses in plants and animals
35) Which component of the PCR mix do researchers manipulate to induce a site-specific mutation? A) Primers B) Taq polymerase C) DNA template D) Reverse transcriptase
36) Which type of disease is LEAST likely to be able to be treated using genome editing with TALEN or CRISPR? A) Trisomy-21 B) Leukemia C) Cystic fibrosis D) Huntingtons
37)
Organisms containing DNA from an outside source are called A) transcribed organisms. B) compound organisms. C) hybrid organisms. D) plasmid organisms. E) transgenic organisms.
38) In some ciliate protozoa, the codons UAA and UAG encode glutamate, rather than acting as STOP codons. How does this compare to other species?
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A) This is unusual – almost all species share the same “universal” genetic code. B) This is typical – every species has its own unique genetic code. C) This is not unusual – while most species have a similar genetic code, there are often variations for some of the amino acids.
39) A researcher wants to create a mouse model for a disease, to allow her team to study possible therapies. The disease is known to be caused by a small deletion that removes a certain gene. Which type of mouse would be the best choice for this purpose? A) Knockout mouse B) Knockin mouse C) Conditional knockout mouse activated by a drug D) Mutant derived by traditional forward genetics screen E) Tissue-specific gene knockout
40)
A key difference between transforming plant cells and human cells is
A) genes to be expressed in human cells require a eukaryotic promoter, and genes to be expressed in plants don't. B) DNA cannot be introduced into human cells. C) Agrobacterium is commonly used as a tool to directly transform plant cells but not human cells. D) a vector is needed to introduce DNA into human cells and not plant cells.
41) The _________blank from Agrobacterium tumefaciens is used in genetic engineering involving crop plant genes. A) restriction endonucleases B) DNA C) Ti vector D) Ti plasmid
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42) After an oil spill, bacteria that can metabolize hydrocarbons are released for bioremediation. After a month, two areas affected by the spill show different levels of improvement. Which factor should be measured to determine the difference in effectiveness between the two sites? A) Temperature B) Oxygen levels C) pH D) Salinity E) Nutrient levels F) All of these factors may play a role.
43) A certain wastewater treatment plant uses aerobic bacteria, anaerobic bacteria, and archaebacteria during secondary treatment of sewage. Unfortunately, during a bad blizzard the aerated tanks froze, killing the microbes inside. What is likely to result? A) Floc levels will diminish. B) Methane production will go down. C) Solid material will not be effectively filtered out. D) Floc will not be effectively filtered out.
44)
A commercially significant human protein now produced in bacteria is A) hemoglobin. B) gamma globulins. C) AZT. D) human insulin. E) HIV vaccine.
45) A rare disease is now understood to be caused by a single mutant gene. When the researcher learns that the gene encodes a ______, he says “Oh good! We may be able to treat the disease with recombinant protein produced in E. coli and delivered by injection.”
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A) protein hormone B) cell-surface receptor C) ribozyme D) component of chromatin E) mitochondrial enzyme
46) A medical researcher is trying to develop a diagnostic technique for a disease which is characterized by replication of a particular chromosomal region. What would be the most appropriate technique? A) FISH B) Gene chip C) Genome sequencing D) White blood cell count
47) An immunoassay was developed to rapidly diagnose patients infected with an emerging virus. However, the researchers discovered that some individuals were producing false negatives when tested, despite being infected with the virus. What might explain this? A) Rapid evolution of the viral antigen B) Changes in the length of the viral DNA C) Number of genome copies carried in each virion D) Changes in the antibody produced by the virus
48) Crop plants have been protected from certain insects by the addition of a gene for a specific insect toxin from the bacterium A) Agrobacterium tumefaciens. B) Bacillus thuringiensis. C) Herpes simplex. D) Pseudomonas. E) tobacco mosaic.
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49) A farmer is growing glyphosate-resistant transgenic soybeans. What are you unlikely to see in those fields during the growing season? A) A tilling machine B) Caterpillars C) Field mice D) Irrigation
50) A friend makes the argument that transgenic crops have only been used to enrich large corporations, not to improve people’s health. What is the best counterexample? A) Golden Rice B) Bt maize C) Glyphosate-resistant soybeans D) Cre-Lox
51) Imagine that a very unusual animal species had the ability to make its own aromatic amino acids using a 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase enzyme similar to that of plants. What would happen if this animal foraged in a field of glyphosate-resistant plants? A) No effect B) They would become sick from the glyphosate that was sprayed on the plants C) They would also become glyphosate-resistant D) They would no longer need to make their own aromatic amino acids
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Answer Key Test name: Chap 17_13e_Raven 1) [A, C, D] 2) [B, D]
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Clarify Question • What is the key concept addressed by the question? o This question addresses restriction enzymes and cloning. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o The frog Xenopus laevis is often used for cell biology research. o Digesting DNA means to treat it with restriction enzymes. o Sticky DNA ends are the result of cutting with most restriction enzymes – they have a staggered cut with one strand longer than the other. Gather Content • What do you already know about restriction enzymes? o Restriction enzymes recognize a specific DNA sequence, ranging from 4 bases to 12 bases, and cleave the DNA at a specific base within this sequence. o The recognition sites for most type II enzymes are palindromes. The palindromic DNA sequence reads the same from 5′ to 3′ on one strand as it does on the complementary strand. o Given this kind of sequence, cutting the DNA at the same base on either strand produces staggered cuts that leaves “sticky ends,” or overhangs. Consider Possibilities • Consider the different answer options. Which can you rule out? o Is your NotI-cut frog DNA going to ligate with blunt AluI ends from Xenopus laevis? No, sticky ends need to bind compatible sticky ends. Version 1
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o Will it ligate with blunt AluI ends from bacteria? No, sticky ends need to bind compatible sticky ends. o Will it ligate with sticky EcoRI ends from Xenopus laevis? No, the sticky ends need to have compatible overhangs. o Will it ligate with sticky EcoRI ends from bacteria? No, the sticky ends need to have compatible overhangs. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Is your NotI-cut frog DNA going to ligate with sticky NotI ends from Xenopus laevis? Yes, that should work fine. o Will it ligate with sticky NotI ends from bacteria? Yes, that should ALSO work fine – as long as the sticky ends are the same, it doesn’t matter where the DNA came from. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what types of DNA would be compatible. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that all that matters when cloning DNA is whether the pieces have compatible ends? o Did you realize that frog DNA and bacterial DNA can ligate together if properly cut? 3) [A, D]
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Clarify Question • What is the key concept addressed by the question? o This question addresses the gel electrophoresis technique. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o Gel electrophoresis is a technique to separate DNA fragments by size. o The bands represent the different size pieces of DNA. Gather Content • What do you already know about gel electrophoresis? o Gel electrophoresis uses a soft agarose gel to separate DNA. o The DNA is pipetted into wells at one end; then electrical current drags the DNA through the gel. o The different sized fragments travel at different speeds, so they separate across the gel. o The bands are visualized using a DNA dye. Consider Possibilities • Consider the different answer options. Which can you rule out? o Could the researcher have forgotten to add antibody, or an RNA probe? No, because those are not used with the simple gel electrophoresis technique. o Could the researcher have forgotten to ligate the DNA fragments? No. The point of a gel is to separate DNA fragments, not connect them. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The researcher could have forgotten to turn on the electric current – then the DNA would stay in the wells and not separate properly. o The researcher could also have forgotten to add the DNA dye – then the DNA would be separated, but the bands would not be visible. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what could have gone wrong with gel electrophoresis. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that antibodies, RNA probes, and membranes are not involved with simple gel electrophoresis? o Did you realize that gel electrophoresis requires electric current, and a DNA dye? 4) [A, C] 5) [A, C] 6) [B, C, E]
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Clarify Question • What is the key concept addressed by the question? o This question addresses biofuels from algae. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about biofuels from algae? o Biofuels produced from microalgae have several advantages over petroleum-based fossil fuels. They are renewable as long as carbon dioxide can be fixed into biomass by photosynthesis. They are more environmentally friendly than fossil fuels, given that carbon in the biofules is derived from present-day atmospheric carbon dioxide and not releasing ancient carbon dioxide that was sequestered millions of years ago. The production of biodiesel from microalgae can also be combined with processes such as wastewater treatment or coupled to carbon dioxide capture systems of fossil fuel burning industrial plants. o A variety of techniques can be used to harvest the lipids from the algae, and this is one of the most expensive parts of algal biodiesel production. Once the lipids have been isolated from the algae, chemical treatments separate the glycerol from the fatty acid chains in the triglyceride. Further refinement yields a biodiesel product. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o In the proposed biofuel system, would kelp fronds provide habitat for endangered sea otters? No. Biofuels are made from microalgae in ponds Version 1
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or tanks, not kelp in the ocean. o Is a benefit of biofuel that it doesn’t need to be burned to provide energy? No, it still needs to be burned like any other fuel. o Is a benefit that the algae can be filtered from the water and used for fuel without refinement? No. The lipids need to be refined from the algae, and this expensive procedure limits the efficiency of the process. o Is a benefit that it contributes less carbon to the atmosphere overall? Yes. Since the algae first captures carbon from the atmosphere (CO2 that it uses to grow), the overal release of carbon from burning the fuel is balanced. o Is a benefit that it is a renewable resource? Yes, unlike fossil fuels, we can grow more algae. o Is a benefit that the system could be paired with wastewater treatment? Yes, and could also be paired with an industrial carbon capture system. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that the benefits of algae biofuels are that they are renewable, they release less carbon overall, and they can be paired with wastewater treatment? 7) [A, B, D] 8) A 9) B 10) C 11) A Version 1
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12) B 13) A • What is the goal of digesting both the gene and the vector with restriction enzymes? • What must be true of the DNA ends for the gene to be able to insert and ligate into the vector successfully? • Can you draw out the results of each enzyme to help answer this question?
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Clarify Question • What is the key concept addressed by the question? o This question addresses restriction enymes. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o Digesting with an endonuclease means to treat the DNA with a restriction enzyme that cleaves within the DNA, only at particular sequences. o Those sequences are called endonuclease recognition sites. o The vector is the plasmid used for cloning the gene. Gather Content • What do you already know about restriction enzymes? o Restriction enzymes recognize a specific DNA sequence, ranging from 4 bases to 12 bases, and cleave the DNA at a specific base within this sequence. o The recognition sites for most type II enzymes are palindromes. The palindromic DNA sequence reads the same from 5′ to 3′ on one strand as it does on the complementary strand. o Given this kind of sequence, cutting the DNA at the same base on either strand produces staggered cuts that leaves “sticky ends,” or overhangs. Consider Possibilities • What other information is related to the question? Which information is most useful? o What is the goal of digesting both the gene and the vector with Version 1
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restriction enzymes? The goal is to allow the insert ends to stick to the ends of the vector, so that it can be ligated in. o What must be true of the DNA ends for the gene to be able to insert and ligate into the vector successfully? The sticky ends of the gene and vector must complement each other – they must be compatible. o Can you draw out the results of each enzyme to help answer this question? o On the vector, Ncol - C*CATGG would create 5’ sticky ends of CATG o Sunl - C*GTACG would create 5’ sticky ends of GTAC o Kpnl - GGTAC*C would create 3’ sticky ends of GTAC o CViAll - C*ATG would create 5’ sticky ends of ATG o Sphl - G*CATGC would create 5’ sticky ends of CATG Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o For digesting the gene to be inserted, only Sphl - G*CATGC would create the same compatible sticky ends as NcoI. o Both create 5’ ends of CATG. o Remember, since the enzyme cleaves on both strands, the other strand is cleaved by SphI like 3’ CGTAC*G 5’. So the overhang with both enzymes is four nucleotides, 5’ CATG 3’. They are compatible ends even though the recognition sites are slightly different. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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o This question asked you to choose the best restriction enzyme. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that the overhangs needed to complement – that is, they needed to be the same? o Did you recognize that a 5’ overhang cannot bind with a 3’ overhang? o Did you try writing out the results of each enzyme? 14) A 15) B 16) C 17) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses restriction enzymes. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o A restriction enzyme cleaves within DNA, only at particular sequences called restriction sites. Gather Content • What do you already know about restriction enzymes? o Restriction enzymes recognize a specific DNA sequence, ranging from 4 bases to 12 bases, and cleave the DNA at a specific base within this sequence. o The recognition sites for most type II enzymes are palindromes. The palindromic DNA sequence reads the same from 5′ to 3′ on one strand as it does on the complementary strand. o Given this kind of sequence, cutting the DNA at the same base on either strand produces staggered cuts that leaves “sticky ends,” or overhangs. Consider Possibilities • What other information is related to the question? Which information is most useful? o We have learned that restriction enzymes usually recognize sites that are palindromes – that is, the sequence reads the same from 5’ to 3’ on each strand.
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The only sequence listed that is a palindrome is TGGCCA. o The double strand would read the same forwards and back: o 5’ TGGCCA 3’ o 3’ ACCGGT 5’ Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to identify the most likely restriction enzyme recognition site. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that restriction sites are usually palindromes? 18) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses restriction enzymes. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o Type II restriction enzymes cut DNA at specific sites, typically palindromes. o The overhangs or sticky ends are the jagged ends of DNA left after restriction digestion, since one strand ends up longer than the other. Gather Content • What do you already know about restriction enzymes? o Restriction enzymes recognize a specific DNA sequence, ranging from 4 bases to 12 bases, and cleave the DNA at a specific base within this sequence. o The recognition sites for most type II enzymes are palindromes. The palindromic DNA sequence reads the same from 5′ to 3′ on one strand as it does on the complementary strand. o Given this kind of sequence, cutting the DNA at the same base on either strand produces staggered cuts that leaves “sticky ends,” or overhangs. Consider Possibilities • Consider the different answer options. Which can you rule out? o Could the resulting sticky ends be 5' GATCC 3' and 5' GATCC 3'? No, because the last C is paired, not overhanging, since the enzyme cut one nucleotide up on the other strand. Version 1
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o Could the resulting sticky ends be 5' GATCC 3' and 5' GGATC 3' No, the sticky ends are always the same on both strands. o Could the resulting sticky ends be 5' GATC 3' and 5' CTAG 3'? No, the sticky ends are always the same on both strands. o Could the resulting sticky ends be 5' G 3' and 5' G 3' or 5' G 3' and 5' C 3'? No, the overhanging portion is the four nucleotides on the other side. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o DO THIS. o If we write out both strands, showing asterisks for the cuts: o 5' G*GATCC 3' o 3’ CCTAG*G 5’ o We see that the two overhangs look like: o 5' GATCC 3' o G 5’ o and o 5' G o 3’ CCTAG 5’ o If you read both 5’ to 3’, they are both the same: 5' GATC 3' and 5' GATC 3'. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what the sticky ends would look like on each Version 1
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strand after being cut with a restriction enzyme. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that the sticky ends are the same for both strands? o Did you realize that the overhanging portion would be only four nucleotides? o Did you try writing out the two strands to help answer the question? 19) D
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Clarify Question • What is the key concept addressed by the question? o This question addresses molecular cloning. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o A DNA fragment is a small piece of DNA. o A plasmid vector is the circular piece of DNA used to grow DNA in bacteria. o Molecular cloning techniques are those used to cut, paste, and amplify DNA in bacteria. Gather Content • What do you already know about molecular cloning techniques? o Molecular cloning involves cutting and pasting pieces of DNA, using enzymes such as restriction enzymes. Consider Possibilities • Consider the different answer options. Which can you rule out? o Would DNA fingerprint data help you to move DNA from one plasmid to another? No, because that is used to match DNA samples at a crime scene, not in cloning. o Would the sequence of PCR primers help you to move DNA from one plasmid to another? No, because normally you would cut the DNA, not PCR it when re-cloning into a new plasmid. o Would data from cloning of Dolly the sheep help you to move DNA from one plasmid to another? No, because that is a different type of cloning. Version 1
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Would restriction maps of the plasmids help you to move DNA from one plasmid to another? Yes, because that would show you what options you have to cut out the DNA from the old plasmid, and how to cut the new plasmid to accept the DNA. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what data would be needed to clone a DNA from one plasmid into another. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that moving the DNA would require cutting it with restriction enzymes? o Did you realize that plasmids have different restriction sites, so to know your options you would need the map? 20) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses restriction enzymes. • What type of thinking is required? o This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. • What key words does the question contain and what do they mean? o Restriction enzymes are enzymes that cut DNA at specific recognition sites. o Cleaving means cutting DNA. o Molecular cloning is the process of cutting and pasting pieces of DNA to make something new, and growing it in large quantity in bacteria. Gather Content • What do you already know about restriction enzymes? o Restriction enzymes recognize a specific DNA sequence, ranging from 4 bases to 12 bases, and cleave the DNA at a specific base within this sequence. o The recognition sites for most type II enzymes are palindromes. The palindromic DNA sequence reads the same from 5′ to 3′ on one strand as it does on the complementary strand. o Given this kind of sequence, cutting the DNA at the same base on either strand produces staggered cuts that leaves “sticky ends,” or overhangs. o These cuts and overhangs are used to cut and paste together pieces of DNA to create new combinations. Consider Possibilities Version 1
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• What other information is related to the question? Which information is most useful? o Would a messy enzyme be useful in molecular cloning? Not likely, because its behavior would be unpredictable. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o In molecular cloning, precision is paramount. If the enzyme cut in the wrong spot, the resulting product would be wrong. o It would be much more difficult to piece together the desired sequence if the enzyme was unpredictable. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked whether a messy restriction enzyme would be a problem. o The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. o Did you recognize that having enzymes that cut reliably in precise places is crucial for successful cloning? 21) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses restriction enzymes. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o A 6.85 kb EcoRI fragment of DNA is a piece of DNA 6850 base pairs long, that was already cut with the enzyme EcoRI. o Restriction sites are recognition sites for different restriction enzymes. o Digesting the DNA with PstI means to treat the DNA with the enzyme PstI, cleaving it. Gather Content • What do you already know about restriction enzymes? o Restriction enzymes recognize a specific DNA sequence, ranging from 4 bases to 12 bases, and cleave the DNA at a specific base within this sequence. o The recognition sites for most type II enzymes are palindromes. The palindromic DNA sequence reads the same from 5ʹ to 3ʹ on one strand as it does on the complementary strand. o Enzymes can cut in more than one spot on the same DNA fragment, as long as the treatment is given enough time. Consider Possibilities • What other information is related to the question? Which information is most useful? o Where will the enzyme cut? Only at the sites marked PstI. o Assume that the reaction is set up so that the enzyme cuts each DNA completely. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Since there are two PstI sites, the fragment will be cut twice, leaving three pieces of DNA. o Remember this was already a DNA fragment, so the ends are free. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more Version 1
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desirable result? o This question asked how many fragments would result for the DNA with a PstI digestion. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that by cutting in two spots, the DNA is broken into three fragments? o Did you read carefully enough to understand that the DNA had already been cut with EcoRI, and now you are cutting with PstI? o If the original fragment was from an EcoRI digestion, how did they get it? Do you think they let that digestion go to completion?
22) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses restriction enzymes. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o A 6.85 kb EcoRI fragment of DNA is a piece of DNA 6850 base pairs long, that was already cut with the enzyme EcoRI. o Restriction sites are recognition sites for different restriction enzymes. o Digesting the DNA with PstI means to treat the DNA with the enzyme PstI, cleaving it. o Migrating on a gel means moving down a gel to the end in the gel electrophoresis technique. Gather Content • What do you already know about restriction enzymes? o Restriction enzymes recognize a specific DNA sequence, ranging from 4 bases to 12 bases, and cleave the DNA at a specific base within this sequence. o The recognition sites for most type II enzymes are palindromes. The palindromic DNA sequence reads the same from 5ʹ to 3ʹ on one strand as it does on the complementary strand. o Enzymes can cut in more than one spot on the same DNA fragment, as long as the treatment is given enough time. Consider Possibilities • What other information is related to the question? Which information is most useful? o What kind of DNA fragments migrate fastest on a gel? The shortest fragments. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Since there are two PstI sites, the fragment will be cut twice, leaving three pieces of DNA. o Remember this was already a DNA fragment, so the ends are free. o What are the lengths of the different PstI fragments? 803, 2622, and 3425. o Which is the shortest and fastest? 803. Reflect on Process
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked how many fragments would result for the DNA with a PstI digestion. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that by cutting in two spots, the DNA is broken into three fragments? o Did you read carefully enough to understand that the DNA had already been cut with EcoRI, and now you are cutting with PstI? o Did you remember that the shortest fragments migrate the fastest on a gel?
23) C 24) D 25) B 26) B 27) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses DNA library construction. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o A cDNA library is a collection of DNAs that represent DNA copies of a mixture of mRNA molecules from a sample. Gather Content • What do you already know about DNA libraries? o Libraries are collections of DNA pieces. o cDNA libraries are DNA copies of mRNAs. o The DNA is synthesized from mRNAs using reverse transcriptase. Consider Possibilities • Consider the different answer options. Which can you rule out? o Would Taq polymerase help you make a cDNA library? No, that enzyme is used to make more DNA copies of DNA. o Would RNA polymerase help you make a cDNA library? No, that enzyme is used to synthesize RNA. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Would reverse transcriptase help you make a cDNA library? Yes, that enzyme will allow you to make cDNA copies of the mRNAs. Version 1
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o Would ligase help you make a cDNA library? Yes, that enzyme will allow you to ligate the cDNAs into the vectors. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what enzymes you need to make a cDNA library. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that you need reverse transcriptase to make the cDNA, and ligase to put it in the vector plasmids? 28) B
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Clarify Question • What is the key concept addressed by the question? o This question addresses gene expression. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o Aerobic and anaerobic conditions refer to conditions with or without oxygen, respectively. Gather Content • What do you already know about gene expression? o Gene expression is controlled at multiple levels: transcriptional, posttranscriptional, transational, and post-translational. o In bacteria, however, the most common and important level of regulation is transcriptional. Consider Possibilities • Consider the different answer options. Which can you rule out? o Would an experiment to sequence the genome address the hypothesis? No, because the genome always stays the same, and the hypothesis was specifically about gene expression. o Would an experiment to PCR a region of the genome address the hypothesis? No, because the entire genome will remain the same in both conditions, and the hypothesis was specifically about gene expression. o Would an experiment to measure levels of RNA polymerase address the hypothesis? No, because levels of RNA polymerase are unlikely to change, and would not be a likely way of regulating gene expression.
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Would creating two cDNA libraries address the hypothesis? Yes, because that would allow you to see differences in transcript levels for different genes in each condition. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked how to test a hypothesis about gene expression in two different conditions. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that the hypothesis was saying that gene expression would be different, and that basically means the set of expressed mRNAs? 29) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses the PCR technique. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o The PCR technique is a method for amplifying DNA. o DNA polymerase is the enzyme that synthesizes DNA. o Heat-stability means that the protein can withstand high temperatures. Gather Content • What do you already know about the PCR technique? o PCR is a method for amplifying DNA from a starting template. o It has three steps that are repeated in multiple rounds: Denaturation, Annealing of primer, and Synthesis. o Each of these steps takes place at a different optimum temperature. Consider Possibilities • Consider the different answer options. Which can you rule out? o Does antibody binding require the enzyme to be heat-stabile? No – there is no antibody binding in the PCR technique. o Does the Synthesis step require the enzyme to be heat-stabile? No. Synthesis uses the enzyme, but it takes place at 72°C. o Does the Primer Annealing step require the enzyme to be heat-stabile? No. Annealing takes place at around 50-60°C. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Does the Denaturation step require the enzyme to be heat-stabile? Yes! Denaturation takes place at 95°C, which is hot enough to quickly destroy normal enzymes. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked why PCR requires a heat-stable polymerase. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that the denaturation step has the highest temperature? 30) C 31) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses DNA techniques. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o Researchers who study ancient DNA are often trying to get DNA out of fossils or specimens that are extremely old, where most of the DNA is long gone. Gather Content • What do you already know about DNA techniques? o Different DNA techniques allow researchers to take a small amount of DNA and make more, or determine the size of DNA fragments, of match DNA to a particular probe. o In this case, when you have a vanishingly tiny amount of DNA like that from an ancient sample, the first thing you must do is to amplify it into a larger amount Consider Possibilities • Consider the different answer options. Which can you rule out? o Does Southern blotting amplify DNA? No, it probes DNA to see if it matches another sequence. o Does gel electrophoresis amplify DNA? No, it sorts DNA fragments by length. o Does inserting the DNA into a vector amplify the DNA? Yes, this can be a way to amplify DNA. But it is not a good way to amplify very tiny amounts of precious DNA, because most DNA will be lost in the Version 1
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process. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Does polymerase chain reaction amplify DNA? Yes! PCR is the best technique for amplify DNA from tiny amounts. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what would be the best technique for a tiny amount of DNA. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that PCR is the best way to amplify small amounts of DNA? 32) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses PCR techniques. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about PCR techniques? o PCR, polymerase chain reaction, mimics the processes of DNA replication. An individual reaction is cycled through a series of steps where each step is analogous to a step in DNA replication: Denaturation, Annealing, and Synthesis. It starts with small amounts of DNA and makes more DNA. o RT-PCR, reverse transcription PCR, makes amplified DNA from mRNA. It can allow you to create an intron-less “gene” matching an expressed mRNA. o Quantitative RT-PCR is a sensitive way to determine relative levels of expression of an mRNA in a particular tissue or sample. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Abby wants to determine changes in gene expression levels in a tissue. She needs a way to quantify mRNA levels, so she uses quantitative RT-PCR. o Bob is trying to extract genetic information from a wooly mammoth fossil. He should amplify DNA, not RNA, since DNA is more stable over millions of years. He uses PCR. Version 1
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o Chris needs to express a gene in bacteria. Bacteria cannot do alternative splicing, and she wants to use a particular expression variant from kidney cells. So she uses RT-PCR to create a DNA copy of the mRNA from those cells. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that PCR is best when simple amplification of DNA is needed? o Did you recognize that RT-PCR is used when you need to create a DNA copy of an mRNA? o Did you recognize that quantitative RT-PCR is best for determining changes in levels of an mRNA? 33) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses molecular techniques. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o Forensic analysis is the science of analzying data from crime scenes. Gather Content • What do you already know about molecular techniques? o There are a variety of molecular techniques for many purposes. o Some are used on RNA, some on proteins, and some on DNA. Consider Possibilities • Consider the different answer options. Which can you rule out? o Would fluorescent in situ hybridization allow the investigators to compare the DNA? No, because FISH is used to detect one particular small target sequence in a mixture of DNA, not to compare two samples overall. o Would RNAi allow the investigators to compare the DNA? No, because that is used to inhibit expression of a gene. o Would RT-PCR allow the investigators to compare the DNA? No, because that is used to create DNA copies of mRNAs. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o Would DNA fingerprinting allow the investigators to compare the DNA? Yes, that is the purpose of that technique. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked which technique is used to identify the source of DNA at a crime scene. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you remember that DNA fingerprinting is the technique used to compare DNA samples? 34) B 35) A 36) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses genome editing. • What type of thinking is required? o This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. Gather Content • What do you already know about genome editing? o Genome editing uses either a TALE protein or an RNA to target a nuclease to a particular gene in the genome. o The nuclease then cuts the targeted DNA, which can be repaired to leave a deletion, or repaired to incorporate a new desired sequence of DNA. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o All of the diseases listed originate with a single abnormal gene that could be targeted by genome editing, except for trisomy 21, which involves a whole extra chromosome. o It would be difficult to regulate the expression of a whole chromosome using the single gene targeting techniques of genome editing. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? o The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. o Did you recognize that genome editing works by targeting and modifying a particular gene in the genome? It would be difficult to use the technique to target multiple genes – or a whole chromosome – at once. 37) E 38) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses the genetic code. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about the genetic code? o The universal nature of the genetic code allows transgenesis to work. o A human gene can be placed into a mouse genome and the cells of the mouse will express the gene. Similarly, a human gene can be placed into the genome of an E. coli bacterium and the bacteria will make the encoded protein. o This is because the cells of organisms of different species interpret genetic information identically. o The genetic code used to decipher the information in a gene is the same code used in bacteria, archaea, and eukaryotes. o There are minor variations to the genetic code, however. For example, the genetic code of mitochondria is slightly different from the genetic code used to interpret nuclear genes. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The ciliates are unusual – the genetic code is nearly universal. That is why scientists are able to express transgenes correctly in different species.
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that the genetic code is nearly (but not quite) universal? 39) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses transgenic mouse technology. • What type of thinking is required? o This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. Gather Content • What do you already know about transgenic mouse technology? o The knockout mouse technique creates a loss-of-function of the target gene by inserting a neomycin cassette. o The knockin mouse replaces the normal gene with a modified version created by the experimenter. o The conditional knockout mouse removes the gene using Cre-lox, but only after treating the animals with a drug. This allows removal of the gene after a certain amount of development. o The tissue-specific gene knockout mouse removes the gene using Crelox, but only in specific tissues in which Cre is active. This allows removal of the gene in a subset of tissues. o A mutant mouse can be derived by a traditional forward genetics screen, but this is expensive and arduous, and not guaranteed to work. This is especially difficult if the mutant would be sickly or lethal, or if the phenotype is unknown. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Given that the experimenter wants to mimic a loss-of-function of a gene throughout the body, the best approach would be to create a Version 1
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knockout mouse. o Doing a traditional screen is too uncertain and expensive. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. o Did you recognize that the knockout mouse is the best choice, because it mimics the disease, but is easier to create than doing a genetics screen? 40) C 41) D 42) F
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Clarify Question • What is the key concept addressed by the question? o This question addresses bioremediation. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about bioremediation? o Certain microorganisms are capable of metabolizing hydrocarbon pollutants. The degradation or metabolism of hydrocarbon pollutants by microorganisms is called bioremediation. o The rate at which these microorganisms metabolize hydrocarbons is affected by a number of variables including temperature, physical and chemical properties of the pollutant, oxygen availability, pH, salinity, other microorganisms present, and perhaps most critically, nutrient availability. o Lab studies have shown that nutritional supplementation of certain microorganisms leads to a significant increase in the rate at which hydrocarbon pollutants can be metabolized. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o All of the listed factors could be important for allowing the bacteria to thrive so they can clean up the oil. Reflect on Process
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that a wide variety of factors can affect the ability of bacteria to survive and multiply, so they are able to metabolize pollutants? 43) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses wastewater treatment with bacteria. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content • What do you already know about wastewater treatment with bacteria? o Wastewater is treated in two, or three, stages called primary, secondary, and advanced treatment. Microorganisms play critical roles in the secondary and sometimes advanced treatment stages. o In aerobic treatment of wastewater, material is fed into large aerated tanks that are continuously agitated where oxidative breakdown of any remaining organic material occurs. The bacteria and other organisms in the aerobic tanks form aggregates called floc. Degradation of the remaining carbon containing compounds in the wastewater occurs on this floc, which is later removed in settling tanks. o Anaerobic digestion of wastewater occurs in sealed reactors called sludge digesters. In the sludge digester, anaerobic bacteria catabolize polysaccharides, lipids, and proteins remaining after primary treatment into their constituent monomers. The resulting fatty acids, amino acids, and sugars, are metabolized into products such as acetate, hydrogen gas, and carbon dioxide. Archaebacteria in the sludge digester can convert these molecules to methane, carbon dioxide, and water. The methane can be burned to heat or power the wastewater treatment plant. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If the aerated tank loses its microbes, the production of floc will diminish. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that the aerobic bacteria in the aerated tanks are responsible for creating floc ? 44) D 45) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses recombinant protein therapy. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content • What do you already know about recombinant protein therapy? o Some diseases are due to the body’s inability to produce a specific protein. We treat these diseases by providing the missing protein. Traditionally, these are isolated from animal tissues, but now we can express proteins in bacteria and other systems using recombinant DNA. An example is insulin, the first medical product produced in this way. Insulin is produced in the pancreas then transported via the bloodstream. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Recombinant protein therapy can be very powerful, but for many types of proteins delivery to the correct location is a problem. o Protein hormones, however, do not have this problem because they normally travel in the bloodstream. Simple injection can get them to the right place. o Other proteins that are embedded in the membrane or are intracellular are more difficult to deliver. Reflect on Process • Did your problem-solving process lead you to the correct answer? Version 1
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If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that protein hormones, like insulin, are especially amenable to therapy with recombinant protein? 46) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses FISH and gene chip diagnostics. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about FISH and gene chip diagnostics? o Fluorescent in situ hybridization (FISH) takes advantage of the ability of DNA to be reversibly denatured and renatured. Hybridization uses a probe with either a fluorescent. In the case of FISH, the target DNA is an actual metaphase spread of chromosomes, or cells with intact chromosomes. This allows the detection of gross chromosomal abnormalities, such as large deletions, inversions, duplications and translocations. o Gene chips also known as DNA microarrays, are collections of hundreds to thousands of different DNA sequences that are spotted onto a solid surface such as a microscope slide. The DNA sequences are usually short chemically synthesized pieces of DNA, or short sequences of DNA amplified by PCR or RT-PCR. Biomarkers can be diagnostic of a disease state, be informative about the progress of a disease, or help monitor the response to therapy. In the case of gene chips, the biomarker is the mRNA synthesized from a particular gene. For example, individuals with certain autoimmune diseases or chronic inflammatory conditions will express different sets of genes in immune cells than will healthy individuals. Gene chips can be used to determine which genes are being expressed and the relative levels of expression for different genes. Version 1
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Since the disease is characterized by a gross chromosomal abnormality, FISH is the best technique to use here. o Whole genome sequencing would work as well, but is too complex and expensive. FISH is more practical. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that the best technique for recognizing a chromosomal duplication is FISH, because there would be an extra fluorescent spot present? 47) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses immunoassays. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content • What do you already know about immunoassays? o Immunoassays can rapidly diagnose viral infections. They are tests that allow the detection of a molecule through the use of an antibody. o Biotechnology companies can make antibodies against a range of viruses and bacteria. These antibodies can be used in immunoassays to detect whether there is virus in a sample collected from a patient. An antibody against a specific virus can be coated into a plastic well on a microtiter plate. When an unknown sample is added to the well, if the virus is present, it will be bound by the antibody. Bound virus can be detected using a second antibody against the virus that has been linked to a fluorescent molecule, or an enzyme that produces a colored product from a suitable substrate. The amount of fluorescence or colored product made by the enzyme, is proportional to the amount of virus present. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The antibody is part of the test; the antigen is made by the virus. o The best explanation for failure of the immunoassay is that the detected antigen has changed, so it is no longer recognizable by the antibody in the test. Version 1
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o The antibodies in an immunoassay can recognize the proteins on the outside of a virus coat, but they cannot recognize features of the viral DNA itself. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that immunoassays rely upon the ability of the antibody to recognize a certain viral antigen protein? 48) B 49) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses transgenic crops. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about transgenic crops? o Agriculturally important broadleaf plants such as soybean have been genetically engineered to be resistant to glyphosate, a powerful, biodegradable herbicide that kills most actively growing plants. Herbicide-resistant crops allow for no-till planting. o Tilling is the process where soils are turned over to prepare them for planting. This acts to remove weeds, which compete with crop plants for nutrients, and improve irrigation. Soils that are not tilled have greater levels of organic and inorganic nutrients that promote growth, often retain more water, and are less prone to soil erosion. Spraying glyphosate on the crop during the season means that weeds are killed eliminating the need to till while the crops are growing. o Bt crops are resistant to some insect pests. The approach is to insert into crop plants genes encoding proteins harmful to insect pests, but harmless to other organisms. The most commonly used protein is a toxin produced by the soil bacterium Bacillus thuringiensis (Bt toxin). When insects ingest Bt toxin, endogenous enzymes convert it into an insectspecific toxin, causing paralysis and death. Because these enzymes are not found in other animals, the protein is harmless to them. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Farmers use glyphosate to destroy weeds without having to till the soil, so a tiller would not be used on the fields. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that glyphosate resistance allows farmers to target weeds without tilling? 50) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses transgenic crops. • What type of thinking is required? o This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. Gather Content • What do you already know about transgenic crops? o Herbicide-resistant crops like glyphosate-resistant soybeans allow for no-till planting. o Bt crops are resistant to some insect pests. o Golden Rice is a transgenic cultivar of rice, genetically modified to express β-carotene, the precursor of vitamin A, which can be converted to vitamin A in the body to alleviate the symptoms of vitamin A deficiency. o Golden Rice was originally constructed in a public facility in Switzerland and made available for free with no commercial incentives. Since its creation, Golden Rice has been improved by public groups and by industry scientists, and these improved versions are also being made available without commercial strings attached. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Golden Rice is the best example of a transgenic crop being produced to help human health, and without a profit motive. Reflect on Process Version 1
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. o Did you recognize that Golden Rice was developed to make rice more nutritious for people, and that it was given away freely? 51) B
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Clarify Question • What is the key concept addressed by the question? o This question addresses herbicide-resistance transgenes. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o EPSP synthase is an enzyme normally only in plants that allows them to synthesize aromatic amino acids. o Glyphosate is an herbicide that kills plants by blocking EPSP. o Glyphosate-resistant plants are resistant because they have multiple copies of the EPSP gene. Gather Content • What do you already know about herbicide resistance transgenes? o Glyphosate is a powerful, biodegradable herbicide that kills most actively growing plants. o It works by inhibiting an enzyme called 5-enolpyruvylshikimate-3phosphate (EPSP) synthase, which plants require to make aromatic amino acids. o Animals do not make aromatic amino acids, so animals living in and around crops, or in waterways receiving crop run off, are unaffected by glyphosate. o To make glyphosate-resistant plants, scientists used a Ti plasmid to insert extra copies of the EPSP synthase gene into plants so they produce 20 times the normal level of EPSP synthase, enabling them to grow despite glyphosate’s inhibition. Consider Possibilities Version 1
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• Consider the different answer options. Which can you rule out? o Would the animal have no effect from eating in the glyphosateresistant field? Most animals do not... but then animals normally do not have the EPSP gene. o Would the animals also become glyphosate-resistant? No, that could only happen if they acquired the transgene in multiple copies – very unlikely to happen. o Would the animals no longer need to make their own aromatic amino acids? Not likely. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Would the animals become very sick from the glyphosate that was sprayed on the plants? Yes, very likely. If they had the plant enzyme, they would be affected just like the plants. Remember that glyphosate is sprayed in the field to kill weeds, so the trangenic plants are not affected but weeds are killed. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what would happen to an animal with EPSP if it ate out of a field of glyphosate-resistant plants. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that the animal could not acquire glyphosateresistance? Version 1
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o Did you realize that the glyphosate would block the animals’ EPSP enzymes?
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Chapter 18 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) Both dideoxy terminator and next-generation sequencing methods require a genomic library to be constructed prior to sequencing the DNA of interest. ⊚ ⊚
2)
true false
In the United States it is currently legal for a company to patent genes. ⊚ ⊚
true false
3) You could safely expect there to be millions of single-nucleotide differences in the genome of yourself as compared to any other random student. ⊚ ⊚
true false
CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 4) Which of the following were challenges that had to be overcome to sequence the genome of wheat,Triticum aestivum? (Select all that apply) A) Lack of advanced sequencing technology B) Large genome size (~5 times as large as human genome) C) High mutation rate of wheat genes D) Lack of interest/support in sequencing the genome E) An abundance of repetitive DNA
5) Almost every cell within one organism has the same genome. In what way(s) can these cells differ from each other? (Select all that apply)
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A) Number of chromosomes B) Ratio of organelles C) Proteins produced D) Number of genes in the DNA E) Surface area of cell membrane
6) An accurate and comprehensive description of pseudogenes must include the statement that ________. (Select all that apply) A) pseudogenes may have some gene-like features such as a promoter and splice sites B) pseudogenes encode proteins, but the translated proteins are non-functional C) pseudogenes can provide insight into the evolutionary history of the related functional gene D) every pseudogene has a similar DNA sequence to some functional gene E) all pseudogenes appear to transcribe other genes when they only transcribe one type of genetic information
7) In your research, you are comparing the transcriptome and the proteome for two related species. One gene in species B has a similar transcript but a much smaller protein than in species A, and the protein seems to be nonfunctional. What do you predict about this gene? (Select all that apply) A) It is a pseudogene. B) It will have an increased number of persistant mutations in species B. C) It probably has a STOP codon early in the coding region. D) It probably has a defect in the enhancer region. E) It probably is not methylated correctly.
8) The important advances stemming from comparative genomics include the ability to ________. (Select all that apply)
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A) draw particular conclusions about species B) draw general conclusions about evolution C) develop a haplotype map D) distinguish how proteins bind to receptors E) infer function about an unsequenced genome using synteny
9) As the director of a new nonprofit functional genomics research center, it is your job to oversee the set up of each laboratory necessary for achieving the center's research goals. Therefore, you plan to include a(n) _____. (Select all that apply) A) DNA microarray facility B) proteomics lab C) lab to improve sequencing speed and cost D) mutagenesis facility E) ancient DNA laboratory
10) The most ethical decisions for usage of genomic data and technology, like sequencing human genomes for customized treatments and constructing deadly pathogens for study, are based on (Select all that apply) A) consensus in the scientific community. B) oversight from governmental agencies. C) the directives of large financial donors. D) what can safely be achieved in the laboratory. E) subjectivity.
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 11) The relative location of genes on a chromosome as determined by recombination frequencies is illustrated in a _______ map.
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A) DNA B) genetic C) chromosomal D) physical
12)
Using actual landmarks within DNA sequences, scientists can generate a _______ map. A) genetic B) DNA C) physical D) chromosomal
13)
Distances on a genetic map are measured in _____ units. A) centromere B) DNA C) dalton D) centimorgan
14)
Recombination frequency between genes can be used to generate a A) genetic map. B) physical map. C) restriction map. D) haplotype map.
15) To avoid confusion and facilitate ease of data interpretation, researchers working on cloned DNA from the same species use
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A) restriction fragment length polymorphisms. B) shotgun sequencing. C) sequenced-tagged sites. D) clone by clone sequencing. E) consensus sequencing.
16) Sequences of DNA assembled by identifying overlaps among smaller DNA segments are known as A) single strand polymorphisms. B) synteny. C) draft sequences. D) the proteome. E) a contig.
17) You have been asked to construct a physical map of the baboon genome. What would be helpful in this task? A) Chromosome maps and STSs B) BLAST and ENCODE data C) Gene linkage data D) Microarrays and SAGE
18) The sequencing method that cuts DNA segments into fragments, arranges those fragments based on overlapping nucleotide sequences, and then clones these fragments is called A) shotgun sequencing. B) clone-by-clonesequencing. C) RFLP sequencing. D) consensus sequencing.
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19) The sequencing method that cuts the DNA of an entire chromosome into small fragments and then clones these fragments is called A) shotgun sequencing. B) clone-by-clone sequencing. C) RFLP sequencing. D) consensus sequencing.
20)
A defining characteristic of draft sequences is that they have A) many gaps in regions of highly repetitive DNA. B) less than 1 error in 10,000 nucleotides. C) been found in various proteomes across the eukaryote life forms. D) been produced by alternative splicing. E) several problems, the main one being their contiguous DNA fragments.
21)
A large portion (45%) of the human genome is composed of A) introns. B) exons. C) templates. D) transposons. E) pseudogenes.
22) When comparing the genomes of prokaryotes verse eukaryotes, it can be accurately stated that A) eukaryoticgenomes are larger than prokaryotic genomes. B) eukaryoticgenomes are smaller than prokaryotic genomes. C) the size of theorganism determines the size of the genome. D) larger and morecomplex organisms have more genes than smaller, less complex organisms.
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23)
The majority of DNA in a human can be described as A) composed of short interspersed elements. B) noncoding. C) simple sequence repeats. D) segmental duplications. E) structural.
24) Given a sequencing reaction length of approximately 500 successive nucleotides, what is the absolute minimum number of sequencing reactions needed to determine the complete human genome, excluding overlap and redundancy? A) 3.1 billion B) 6200 C) 12.4 million D) 6.2 million
25) The organism with the largest relative genome size is _____ and the organism with the highest number of actual genes is ______. A) rice; human B) human; human C) fruit fly; human D) yeast; yeast E) human; rice
26) Humans are diploid organisms, containing two sets of chromosomes. How many sets of chromosomes does wheat,Triticum aestivum, have?
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A) 1 B) 2 C) 4 D) 6 E) 8
27) You are studying a novel protein. To learn more about it, you performed a screen in yeast to identify proteins that could interact with it. From the screen you got a clone for a second gene. You had the clone sequenced, and you translated the gene sequence on your computer. What is the next logical step to learn more about the function of these two proteins? A) Run a BLAST search. B) Identify the intron/exon organization. C) Localize the gene to a specific chromosomal region. D) Search the human genome sequence for your clone.
28) Your research group has recently determined the complete genomic sequence of the organism Examus biologisium. You instruct your group to begin sequence annotation, which involves A) shotgun cloning. B) the alignment of contigs. C) the identification of open reading frames. D) the construction of a genetic map.
29)
Silent copies of genes that have been inactivated by mutations are called A) pseudogenes. B) clones. C) exons. D) introns.
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30) A human gene is composed of numerous fragments of protein-encoding information known as _______. A) DNA B) mRNA C) exons D) introns
31) Mobile bits of DNA that can jump from one location on a chromosome to another location are called A) simple sequence repeats. B) transposons. C) exons. D) introns. E) pseudogenes.
32)
Long interspersed elements (LINEs) are a type of A) pseudogene. B) proteome. C) exon. D) intron. E) transposon.
33) Some regions of chromosomes remain highly condensed, tightly coiled, and untranscribed throughout the cell cycle. These regions are referred to as
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A) transposable elements. B) single sequence repeats. C) noncoding DNA. D) short interspersed elements. E) constitutive heterchromatin.
34)
Non-coding DNA regions within a gene are referred to as A) introns. B) exons. C) templates. D) transposons. E) pseudogenes.
35) Groups of related, but distinctly different genes that appear to have arisen from a single ancestral gene are referred to as A) segmental duplications. B) pseudogenes. C) tandem clusters. D) multigene families. E) expressed sequences.
36) The reason segmental duplications pose a logistical challenge in the proper alignment of DNA sequences is that they A) are inherentlyrepetitive. B) contain largenumbers of LINEs, which interfere with sequence annotation. C) interfere with BLAST analysis. D) are often foundin areas of constitutive heterochromatin.
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37)
The ENCODE project seeks to A) sequence the genomes of all animals. B) sequence the DNA of all organisms. C) identify the coding sequences of human DNA. D) identify the functional elements of the human genome. E) identify the proteins encoded by the human genome.
38) The current estimates of the ENCODE project for percent functionality of the human genome based on the ENCODE definition of functionality is _____ the estimate of functionality based on the selected-effect functionality definition. A) greater than B) less than C) equal to
39)
The inclusive term that describes all of the DNA in the nucleus of a cell is its A) genome. B) chromosome. C) gene. D) proteome.
40) Rice and its grain relatives, maize, barley, and wheat, diverged from a common ancestor 50 million years ago. However, the chromosomes of these plants demonstrate extensive conserved arrangements of segments. This phenomenon is called A) linkagedisequilibrium. B) single nucleotidepolymorphisms. C) contig. D) synteny. E) expressed sequence equilibrium.
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41) In vertebrates, the family of myogenic regulatory factors (MRFs) plays a major role in muscle development. This family consists of four related genes which have distinct but overlapping functions. This gene family is represented by only a single gene in Drosophila, called nautilus. You want to know whether nautilus plays a role like all of the MRFs put together, or more like one in particular. What is a quick and easy way to begin to address this question? A) Compare the DNA and protein sequences of all the genes to determine if nautilus is more similar to one MRF than another. B) Use a DNA microarray to compare gene activation patterns between nautilus and the MRFs. C) Compare the proteome of a cell expressing nautilus to the those of cells expressing each of the MRFs in turn. D) Generate four transgenic Drosophila strains that express the MRFs in a mutant nautilus background.
42) As a scientist working for an anti-bioterrorism task force, you are asked to evaluate some biological samples for the presence of Yersinia pestis, the organism that causes the plague. After confirming that the samples do contain Y. pestis, you instruct your team to begin sequencing the strain. Since the genome sequence of Y. pestis is already known, why would sequencing this strain be useful? A) To provide better data for the genome database B) To establish the course of infection, and determine whether the strain is altered by causing infection C) To help determine the source of the strain, and learn whether it has been genetically engineered D) To create a vaccine for this particular strain
43)
How did the rice genome project influence other genome projects? A) It was the first genome sequenced, so it proved it could be done. B) It sped up the genome analysis of other cereal crops, due to synteny. C) It sped up the analysis of the human genome, since rice has even more genes. D) It helped analysis of all genomes, since it was the basis of the ENCODE algorithms.
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44) with
Microarrays are created by robotically placing DNA on to a microscope slide and probing
A) RNA from thetissue of interest. B) another DNA fromthe tissue of interest. C) SNPs from thetissue of interest. D) STSs from thetissue of interest. E) clone-by-clone sequencing.
45)
The best technique for detecting chromosomal abnormalities is A) EST. B) FISH. C) STS. D) SNP.
46) Your research team has been asked to quantify levels of cellular RNAs in rats before and after exercise. The primary focus of your work will be to analyze the A) proteome. B) spliceosome. C) nucleosome. D) different RNA motifs. E) transcriptome.
47) A pharmaceutical company is developing a new drug to treat a rare disease. They need to determine which of the cell’s proteins can bind the drug. Which tool can help them survey the proteome for drug interactions?
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A) Protein microarray B) DNA microarray C) SAGE D) ENCODE E) Using a monoclonal antibody
48) Based on shared genetic variation in humans, scientists have been able to estimate the timing of significant population expansion events in history. How long ago do scientists think some subpopulations in Asia, Europe, and the Americas have had bottlenecks of total population sizes in only the low thousands? A) less than 1,000 years ago B) 5,000 to 10,000 years ago C) 15,000 to 20,000 years ago D) 30,000 years ago E) 90,000 to 100,000 years ago
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Answer Key Test name: Chap 18_13e_Raven 1) FALSE 2) FALSE 3) TRUE
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Clarify Question What is the key concept addressed by the question? ● This question addresses genetic variation in humans. What type of thinking is required? ● This question is asking you to take what you already know and apply it to this unfamiliar scenario. What keywords does the question contain and what do they mean? ● Single-nucleotide variation refers to differences in a single nucleotide, as compared to structural variation that includes differences of 50 or more base pairs. Gather Content What do you already know about genetic variation in humans? ● To date, thousands of individual human genomes have been sequenced, and large amounts of genetic divsersity have been observed across those data. ● Single-nucleotide variation is one particular source of genetic variation, of which there are many. Consider Possibilities Consider the different answer options. ● It is a given that genetic variation exsists across individuals, but at the same time humans share virtually all of the same genes. The key to answering this question is, where can genetic variation exist in the genome and what is the scale of those differences? Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● Taking into consideration that only 1% of the genome actually codes for genes, there is significant room for single-nucleotide variation to be present across individuals without negatively impacting gene expression. Based on direct comparison of fully sequenced human genomes, the Version 1
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expected number of differences in single nucleotides is approximately 4,000,000. Therefore, it is safe to assume the number of difference between yourself and any random student is also counted in the millions Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked how much genetic variation can you expect between individual humans. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you remember that the majority of DNA is non-coding, and can therefore vary considerably without deleterious effects? 4) [B, E] 5) [B, C, E] 6) [A, C, D] 7) [A, B, C]
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Clarify Question • What is the key concept addressed by the question? o This question addresses pseudogenes. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o The transcriptome is the set of all transcripts in a cell (i.e., mRNAs and other RNAs). o The proteome is the set of all proteins in a cell. Gather Content • What do you already know about pseudogenes? o Pseudogenes are genes that have recently become nonfunctional, often due to a frameshift or nonsense mutation that create an early STOP. Consider Possibilities • Consider the different answer options. Which can you rule out? o Can you predict that this gene has a defect in the enhancer region? No, because it is being transcribed normally – only the protein is wrong. o Can you predict that this gene is not methylated correctly? No, because that would affect its transcriptional expression, but that aspect is normal. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Can you predict that this gene is a pseudogene? Yes, it fits the Version 1
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description of a pseudogene. o Can you predict that this gene will have an increased number of persistant mutations in species B? Yes, because there is no selection against mutations in a nonfunctional gene. o Can you predict that this gene probably has a STOP codon early in the coding region? Yes, that would explain why the protein is smaller and nonfunctional. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what you would predict about a nonfunctional gene. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that this scenario describes a pseudogene? 8) [A, B, E] 9) [A, B, D]
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Clarify Question • What is the key concept addressed by the question? o This question addresses functional genomics. • What type of thinking is required? o This question is asking you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. • What key words does the question contain and what do they mean? o Functional genomics focuses on understanding the connection between genes and phenotype. In other words, how exactly does a gene influence the workings of the cell? Gather Content • What do you already know about functional genomics? o We can think of functional genomics as the study of “what genes do”. o By focusing on the function of genes, we can understand how certain mutations or disruptions of gene expression can be connected to disease. Consider Possibilities • Consider the different answer options. Which can you rule out? o Would a lab to improve sequencing speed and cost fit in with the goals of a functional genomics center? Not really. While important, sequencing efficiency does not directly address functional genomics. o Would an ancient DNA laboratory fit in with the goals of a functional genomics center? Not really. Sometimes ancient DNA could provide some insight into gene changes and disease, but studying ancient DNA is not a direct approach to understanding gene function. It is more likely to provide insight into evolution. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Would a DNA microarray facility fit in with the goals of a functional genomics center? Yes, that allows researchers to study how the genes are expressed in different cell types and conditions – an important aspect of gene function. o Would a proteomics lab fit in with the goals of a functional genomics center? Yes, this allows the researchers to study large numbers of proteins in different cell types and conditions. o Would a mutagenesis facility fit in with the goals of a functional genomics center? Yes, that would allow researchers to see directly what the phenotypic outcome is for loss-of-function of a particular gene. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what should be included in a functional genomics center. o The question required you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. o Did you recognize that functional genomics is about connecting genes to phenotype? 10) [A, B, D, E] 11) B 12) C 13) D 14) A 15) C Version 1
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16) E 17) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses physical mapping. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o A physical map is a map of the DNA itself, starting with clones and eventually down to the nucleotide level. Gather Content • What do you already know about physical mapping? o The ultimate physical map is the base-pair sequence of an entire genome. o This is achieved by connecting clones into contigs, and eventually getting the detailed sequence of each. Consider Possibilities • Consider the different answer options. Which can you rule out? o Would BLAST and ENCODE data be helpful for making a physical map? No, because these data help you interpret the structure and function of genes after the nucleotide sequence has been established. o Would gene linkage data be helpful for making a physical map? No, because gene linkage data provides a genetic map, but it needs to be aligned with the physical map to know real locations of genes. o Would microarrays and SAGE be helpful for making a physical map? No, because these tools allow you to analyze the transcriptome, but not the DNA structure of the genome.
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Would chromosome maps and STSs be helpful for making a physical map? Yes. The chromosome maps represent a physical map of each chromosome. The STSs are sequence-tagged sites. STSs are short, unique stretches of DNA that are useful for aligning clones. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what would help you to generate a physical map. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that a physical map is a map of the DNA itself, and that chromosome maps and sequence-tagged sites would be most useful? 18) B 19) A 20) A 21) D 22) A 23) B 24) D
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Clarify Question • What is the key concept addressed by the question? o This question addresses genome size. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o A sequencing reaction is the reaction used to determine the sequence of a piece of DNA. o The complete human genome refers to one complete set of 23 chromosomes. Gather Content • What do you already know about genome size? o Genome size is highly variable, and not always correlated with organismal complexity. o The human genome size is about 3 billion base pairs. Consider Possibilities • Consider the different answer options. Which can you rule out? o Would 3.1 billion sequencing reactions cover the genome? Yes, but that is too many. Each reaction could be only 1 nucleotide long and that would be enough! o Would 6200 sequencing reactions cover the genome? No, that is not nearly enough. That would only cover 3.1 million base pairs. (6200 x 500 = 3,100,000) o Would 12.4 million sequencing reactions cover the genome? Yes, but that is too many. That would cover over 6 billion nucleotides. (12,400,000 x 500 = 6,200,000,000) Version 1
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The human genome size is 3.1 billion base pairs. o Would 6.2 million sequencing reactions cover the genome? Yes, that is the bare minimum number. That would cover 3 billion nucleotides. (6,200,000 x 500 = 3,100,000,000) Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to determine the minimum number of sequencing reactions to sequence the entire human genome. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you remember that the human genome is about 3 billion base pairs long? 25) E 26) D 27) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses sequence analysis. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o A novel protein is one that has not yet been well-studied, so we don’t know much about it. o A screen is a way of picking out relevant genes from a large number of candidates. o Having a clone sequenced means to have the DNA “read”; the sequence is sent to you in an email. o Translating a sequence on the computer means to use software to read the codons of the DNA into the amino acid sequence. Gather Content • What do you already know about sequence analysis? o Usually we have DNA sequenced. Even if we want to learn about a protein, it is easier to have a gene sequenced and infer the protein sequence from the codons. Consider Possibilities • Consider the different answer options. Which can you rule out? o After sequencing and translating the clone, you have a protein sequence. What next? Your goal is to learn what kind of cellular process or pathway the protein is involved in. o Would it be helpful to identify the intron/exon organization? Not particularly. That won’t tell you anything about the cellular function of Version 1
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the proteins. o Would it be helpful to localize the gene to a specific chromosomal region? Not really. Again, that won’t tell you anything about the cellular function of the proteins. Different chromosomes carry genes with all kinds of functions. o Would it be helpful to search the human genome sequence for your clone? No, your clone was from yeast, so the exact same sequence won’t be there. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Would it be helpful to run a BLAST search? Yes! In just a few moments, you will be able to find the proteins – whether in yeast or other species – with the most similar sequence. Some of these will likely have research articles describing their functional role. o The BLAST search will also reveal special protein domains that may be important to function, such as a DNA-binding motif. o Remember, the BLAST search is for the second protein. But since the two proteins interact – that is, bind each other – it is likely that they work together in the same cellular process. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what step should come next after sequencing a clone. o The question required you to take what you already know and apply it Version 1
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to this unfamiliar situation. o Did you recognize that the protein sequence could reveal the function of the protein, but only if you compared it to a database of other known proteins? 28) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses genome analysis. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o Sequence annotation refers to making notes in the genome database about the locations and details of genes. Gather Content • What do you already know about genome analysis? o Sequencing a genome is not enough to be useful. o To make sense of the sequence of nucleotides, we have to figure out where the genes lie. Consider Possibilities • Consider the different answer options. Which can you rule out? o Would the next step be shotgun cloning? No, that would be part of the sequencing effort. o Would the next step be the alignment of contigs? No, that would be part of the sequencing effort. o Would the next step be the construction of a genetic map? No, that would not directly annotate the genome sequence unless the genes were aligned to molecular markers. Choose Answer • Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer? o Would the next step be the identification of open reading frames? Yes, this would show where the likely genes are. This is an important part of sequence annotation. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to describe what would occur as part of sequence annotation for a genome. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that finding open reading frames – i.e., the locations of genes – is an important part of sequence annotation? 29) A 30) C 31) B 32) E 33) E 34) A 35) D 36) A 37) D 38) A 39) A 40) D 41) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses sequence analysis. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o Myogenic regulatory factors (MRFs) are a gene family in vertebrates that are important for muscle development. o Drosophila is the genus name for fruit flies, the workhorse of genetic research. Gather Content • What do you already know about sequence analysis? o Sequence analysis can use a DNA sequence to reveal information about a protein, by “translating” the DNA on a computer. o By looking at protein domains and motifs, we can learn possible roles for that protein. o Comparing two proteins can show us how similar they are. If the protein sequences are similar, that suggests they play similar roles. Consider Possibilities • Consider the different answer options. Which can you rule out? o Is it quick and easy to generate four transgenic Drosophila strains that express the MRFs in a mutant nautilus background? No, this is not quick and easy – although it would be interesting. o Is it quick and easy to use a DNA microarray to compare gene activation patterns between nautilus and the MRFs? Not really. You would need to establish transgenic lines so that the MRFs were in Version 1
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Drosophila, to compare gene activation to nautilus (or vice versa). o Is it quick and easy to compare the proteome of a cell expressing nautilus to the those of cells expressing each of the MRFs? No, because again you would need to establish the transgenic lines to get the MRFs in Drosophila. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Is it quick and easy to compare the DNA and protein sequences of all the genes to determine if nautilus is more similar to one MRF than another? Yes! This could be done in an afternoon, thanks to the genome data available. This would give you some idea of what to expect, based on how similar the protein sequences are. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what would be the quick and easy way to see which vertebrate MRF gene was most similar to the nautilus gene. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that sequence analysis is a quick and easy way to learn about the likely functions of a gene? 42) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses genome analysis. • What type of thinking is required? o This question is asking you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. • What key words does the question contain and what do they mean? o Bioterrorism is terrorism that uses disease organisms to harm and frighten people. o Yersinia pestis, the organism that causes the plague, is a Gramnegative bacterium that has been responsible for killing millions of people in historical outbreaks. o The genome sequence is the complete sequence of its DNA. Since Yersinia is a bacterium, sequencing the small genome is not as difficult as for a eukaryote. Gather Content • What do you already know about genome analysis? o We have learned that every organism carries small polymorphisms – little sequence differences in the genome. o How might these be useful here? Consider Possibilities • Consider the different answer options. Which can you rule out? o Would sequencing the genome help by providing better data for the genome database? No, that’s not really a big priority. o Would it help by establishing the course of infection, and determining whether the strain is altered by causing infection? No, that’s not likely. o Would it help to create a vaccine for this particular strain? No, if a Version 1
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vaccine was being developed they would focus on particular proteins, not the whole genome. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Would sequencing the genome help to determine the source of the strain, and learn whether it has been genetically engineered? Yes. Small differences, or polymorphisms, could connect the strain to a source. This would help identify who was spreading it. Furthermore, it would be important to know whether it had been engineered to be even more deadly. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked why you would sequence a genome of a possible bioterrorism germ. o The question required you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. o Did you recognize that sequencing the genome could reveal polymorphisms to help trace the strain to its source? o Genome sequencing might also reveal a genetically engineered change to the genome. 43) B
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Clarify Question • What is the key concept addressed by the question? o This question addresses the rice genome. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o The rice genome project determined the DNA sequence for rice, Oryza sativa. Gather Content • What do you already know about the rice genome? o The rice genome was found to have extensive synteny – similar gene order – as the other cereal crops. o This information can be used to put genome fragments in the correct order for the other species. Consider Possibilities • Consider the different answer options. Which can you rule out? o Was the rice genome the first genome sequenced? No, microbial genomes were the first to be sequenced. o Did the rice genome speed up analysis of the human genome, since rice has even more genes? No. Rice does have more genes, but these were too different to be very useful in analysis of the human genome. Furthermore, the human genome was sequenced first. o Did the rice genome help analysis of all genomes, since it was the basis of the ENCODE algorithms? No. The ENCODE algorithms were not based on the rice genome.
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Did the rice genome speed up analysis of other cereal crops, due to synteny? Yes. The rice genome has a similar gene order as other cereal crops, so it helps to align fragments of larger genomes like the wheat genome. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked how the rice genome project influenced other genome projects. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you remember that the rice genome and the other cereal crops have synteny, or similar order of related genes? o Did you realize that this information helps researchers to analyze the data for the other crop plants? 44) A 45) B 46) E
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Clarify Question • What is the key concept addressed by the question? o This question addresses the transcriptome. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o Quantifying levels of cellular RNA means to measure the amount of RNAs such as mRNAs and rRNAs. Gather Content • What do you already know about the transcriptome? o The transcriptome is the set of transcripts, or RNAs, that are expressed in a cell. o It will differ between different cell types, and between different conditions. Consider Possibilities • Consider the different answer options. Which can you rule out? o Does studying RNAs involve studying the proteome? No, because the proteome refers to all the proteins of a cell. o Studying the spliceosome? No, because the spliceosome is the name for the cellular machinery that splices mRNAs. o Studying the nucleosome? No, because the nucleosome is the wound up module of chromatin in the chromosome. o Studying different RNA motifs? No, because you were asked to measure levels of large numbers of RNAs, not studying details of particular RNAs.
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Does studying RNAs involve studying the transcriptome? Yes, because that is the term for all the RNAs of a cell. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what you would study to measure RNAs. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that the RNAs of a cell represent the transcriptome? 47) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses proteomics. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o The proteome is the complete set of proteins in a cell. Gather Content • What do you already know about proteomics? o Proteomics techniques involve ways of analyzing hundreds or thousands of proteins at a time. Consider Possibilities • Consider the different answer options. Which can you rule out? o Would a DNA microarray help to survey the proteome for proteins that bind a new drug? No, because that only reveals the presence of DNA or RNA in a sample. o Would SAGE help? No, because that is a technique for analyzing mRNAs in a sample. o Would ENCODE help? No, because ENCODE is the name of a project that identifies elements in the genome. o Would using a monoclonal antibody help? No, because each monoclonal antibody can only bind one protein – you would need thousands of antibodies to survey the proteome. Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Would a protein microarray help to survey the proteome for proteins that bind a new drug? Yes. That is a technique that allows you to recognize the presence of up to thousands of proteins at once. o You could treat cells with the drug, use a column to capture the drug and bound proteins, then apply those bound proteins to a protein microarray to identify them. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked which technique could be used to survey the proteome for drug interactions. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that protein microarrays can be used to recognize the presence of multiple proteins in a sample? 48) C
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Chapter 19 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) Novel phenotypic adaptations can arise as a result of changes only in how organisms develop. ⊚ ⊚
true false
CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 2) Check all of the features of C. elegans that make it a great model system to study developmental processes. A) C. elegans is ubiquitous in the wild B) C. elegans is small and fast growing C) A complete lineage map exists D) The organism is transparent E) C. elegansis useful in experimental genetics
3) In a 32-cell stage tunicate embryo, if the vegetal marginal cells lack a functional FGF receptor, which structure(s) will fail to develop? (Select all that apply) A) Notochord B) Mesenchyme C) Muscle D) Nerve cord
4)
What are the characteristics of stem cells? (Select all that apply)
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A) Totipotent stemcells are part of a committed pathway within one cell lineage that will giverise to one specific cell type. B) Pluripotent stemcells are descendants of the totipotent stem cells of the embryo. C) A fertilized eggis a type of totipotent stem cell. D) Pluripotent stemcells can differentiate into any cell type, except for totipotent stem cellsand the cells of the placenta.
5)
Check all of the main functions of MADS box-containing genes in plants. A) The transition from vegetative to reproductive growth B) Root development C) Generation of leaf form D) Floral organ identity
6) What would you predict about the presence of Hox genes in the last common ancestor of vertebrates and invertebrates? (Select all that apply) A) The genes contained homeoboxes. B) The genes specified anterior-posterior development. C) If mutated, there would be an extra pair of wings and legs growing from the head. D) The genes were in four clusters. E) The genes were in anterior-posterior order on the chromosome. F) The genes contained a MADS-box. G) That ancient ancestor was too primitive to have Hox genes.
7)
When differentiation occurs, cells may also change in _____. (Select all that apply) A) genetic content B) size C) shape
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MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 8) A fertilized egg is called a(n) A) zygote. B) ovule. C) oocyte. D) blastocyst.
9) During which initial period of division in a zygote is there no increase in the overall size of the embryo? A) Mitosis B) Cleavage C) Meiosis D) Fertilization
10) A zygote is a fertilized egg formed by an egg and a sperm. The zygote undergoes many mitotic events as it develops into a solid ball of cells (i.e., blastomeres) called a blastula. What changes occur in this early cleavage? A) During the initialstages of cleavage, there is a tremendous increase in the number and size ofblastomeres. B) During the initialstages of cleavage, there is a tremendous decrease in the number and size ofblastomeres. C) During the initialstages of cleavage, there is a tremendous increase in the number of cellscoupled with a decrease in the size of the cells composing the developingorganism. D) During the initialstages of cleavage, there is no increase in the number of cells of thedeveloping organism, but the size of the cells increases.
11)
A zygote initially divides into smaller cells, each called a(n)
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A) blastomere. B) gastrula. C) neurula. D) cleavage cell. E) embryonic cell.
12) In contrast to the cell cycle of adult somatic cells, the dividing cells of an early embryo lack which cell cycle stage(s)? A) M B) S C) G1 and G2 D) interphase
13) a(n)
Caenorhabditis elegans is an organism with exactly 959 somatic cells. This organism is
A) fruit fly. B) earthworm. C) nematode. D) angiosperm. E) fungus.
14)
A complete cell lineage map exists for A) C. elegans. B) Drosophila. C) mouse. D) human.
15)
Plants have special groups of self-renewing cells called
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A) root cells. B) chloroplasts. C) cast cells. D) meristems.
16) Plants do not utilize the process of cell migration in their development. Instead plants utilize A) the process of building themselves inwardly via the meristems present in the developing plant tissues. B) the process of building themselves outwardly via the meristems present in the developing plant tissues. C) the process of building themselves with epidermal tissues, which eventually become ground tissues, which can then begin the process of photosynthesis. D) the process ofbuilding themselves by using their vascular tissues to form meristems, whichpromotes normal development in the plant.
17) In Drosophila, the cells created by cleavage contain different developmental signals from the egg called cytoplasmic A) stem cells. B) signals. C) determinants. D) junctions.
18)
What can be said about animal and vegetal poles?
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A) When animal pole cells are cultured with vegetal pole cells, some of the animal pole cells become mesoderm. B) When animal pole cells are cultured with vegetal pole cells, some of the vegetal pole cells become mesoderm. C) Isolated animal cells develop as endoderm. D) Isolated vegetal cells develop as ectoderm.
19)
In general, the blastomeres of the_________blank form the ectodermal tissues. A) animal pole B) vegetal pole C) equator region D) membrane
20)
In general, the blastomeres of the_________blank form the endodermal tissues. A) animal pole B) vegetal pole C) equator region D) membrane
21)
What can be said about Drosophila development?
A) Paternal genesdetermine the initial course of development after fertilization. B) Zygotic genesdetermine the initial course of development after fertilization. C) Maternal genesdetermine the initial course of development after fertilization. D) Syncytialblastoderm genes determine the initial course of development afterfertilization.
22)
A muscle precursor cell expressing the MyoD1 gene would be considered to be
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A) pluripotent. B) determined. C) differentiated. D) totipotent.
23) If cells from a wing are transplanted to the leg prior to their determination, into what will they likely develop? A) Wing cells B) Leg cells C) A mixture of wing and leg cells D) Cannot be determined E) Undifferentiated cells
24) In a 32-cell stage tunicate embryo, vegetal marginal cells that lack functional genes for both macho-1 and the FGF receptor would develop as what cell type? A) Mesenchyme B) Muscle C) Notochord D) Nerve cord
25) Very early in development, each cell is capable of expressing all its genes. This is referred to as A) determination. B) specification. C) bipotentialinduction. D) totipotency. E) multipotency.
26)
Adult stem cells are usually
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A) differentiated. B) totipotent. C) pluripotent. D) multipotent.
27)
Briggs and King demonstrated nuclear transplantation in A) sheep. B) frogs. C) pigs. D) lizards. E) fish.
28)
How did Briggs and King move the nuclei between cells? A) With a glass pipet B) With a dissecting needle C) With a scalpel D) With forceps
29) Scientists attempted for many years to conduct nuclear transplants but failed. However, geneticists had success in cloning a sheep. They were successful because they A) picked a cell very early in development. B) replicated the blastomeres before insertion. C) delayed transcription in the blastomeres. D) treated the nucleus with sheep plasma before nuclear insertion. E) utilized a new micro pipette technique.
30)
Egg cells were combined with_________blank to form the cloned sheep named Dolly.
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A) skin cells B) sperm cells C) mucous membrane cells D) mammary cells E) ovarian cells
31) What was the most significant research finding that resulted from the successful cloning of Dolly? A) The key to cloning success is to pick a donor cell from very early in development. B) Cloned animals are capable of producing normal offspring. C) The nucleus of a fully-differentiated cell can be reprogrammed to be totipotent. D) Genetic imprinting, which occurs in adult reproductive tissue, can take months for sperm and years for eggs.
32) The low success rate and age-related diseases associated with reproductive cloning is thought to be due to A) lack of genetic imprinting. B) the age of the donor cell. C) cell cycle problems. D) large offspring syndrome (LOS).
33)
The main difference between therapeutic cloning and reproductive cloning is that
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A) in therapeutic cloning, embryonic stem cells are extracted from the blastocyst, while in reproductive cloning, the blastocyst is kept intact and implanted into a surrogate mother. B) somatic cellnuclear transfer is used for therapeutic cloning, while gametic cell nucleartransfer is used in reproductive cloning. C) unlike cells used for reproductive cloning, cells grown for therapeutic purposes do not display genetic imprinting problems. D) unlike cells used for reproductive cloning, cells grown for therapeutic purposes do not require the destruction of embryos.
34)
In insects, the passage from one body form to another is called A) pupation. B) ecdysis. C) metamorphosis. D) transference.
35)
Drosophila eggs acquire an initial asymmetry before fertilization as a result of A) production of bicoid proteins in one end of the egg. B) maternal DNA molecules being deposited in one end of the egg. C) nurse cell migration to one end of the egg. D) maternal mRNA being deposited in one end of the egg. E) attachments of cadherins to one end of the cell.
36) Which proteins are encoded by genes that code for the first mRNAs transcribed in Drosophila embryos? A) Gap and Pair-rule proteins B) Dorsal proteins C) Bicoid and Nanos proteins D) Caudal and Hunchback proteins E) Morphogen proteins
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37)
Signal molecules that determine relative positions during development are known as A) inductors. B) organizers. C) cadherin domains. D) derepressers. E) morphogens.
38) Which genes are expressed inDrosophila after pattern formation along the A/P axis has been successfully established? A) totipotent genes B) bicoid genes C) segment polarity genes D) gap genes E) homeotic genes
39)
A fly embryo that expresses the bicoid mutant phenotype
A) is genetically wild-type, but has a bicoid mutant mother. B) is mutant for bicoid and has a bicoid mutant mother. C) may be either genetically wild-type or mutant for bicoid, but definitely has a bicoid mutant mother. D) can be either genetically wild-type or mutant for bicoid. The genotype of the mother cannot be determined from the information provided.
40) If one were to inject cytoplasm containing Bicoid into the middle of a Drosophila egg immediately prior to fertilization, the embryo would
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A) try to formanterior structures in the middle of its body. B) try to form posterior structures in the middle of its body. C) not develop at all. D) develop normally.
41) Overexpression of caudal in the early Drosophila embryo, at a level high enough to overcome inhibition by Bicoid protein, would A) interfere with the development of anterior structures. B) interfere with the development of posterior structures. C) interfere with the development of both anterior and posterior structures. D) have no effect since the cytoplasm has already been determined.
42) There are cases, particularly in fruit flies, in which a normal body part grows in the wrong spot. For instance, legs on the head growing instead of antennae, or a second set of wings behind the normal pair. What can explain this? A) These are due to the reappearance of stem cells, which are totipotent. B) These are due to misregulation of hormones from environmental contamination with pesticides. C) These occur as a result of mutations in homeotic genes, which normally act to direct development along the anterior-posterior axis. D) These naturally occur sometimes in animals that have metamorphic development, due to different organization of homeotic gene expression in larvae versus adults.
43)
What is the correct order of gene expression in the early Drosophila embryo? A) pair-rule genes, gap genes, segment polarity genes B) gap genes, pair-rule genes, segment polarity genes C) gap genes, segment polarity genes, pair-rule genes D) segment polarity genes, pair-rule genes, gap genes
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44)
If a Drosophila mother is mutant for dorsal, her embryos would A) develop normally. B) have a delay in the development of dorsal/ventral polarity. C) lack dorsal structures. D) lack ventral structures.
45) Many insects, like moths and flies, undergo complete metamorphosis. What would you predict about gene expression in these two kinds of insects? A) The basic organization of homeotic genes is the same in both larvae and adult, but the expression of some other genes must be different. B) Completely different sets of genes must be used in the development of larvae and the adult. C) The order of homeotic genes along the body axis must be different in larvae and adult. D) The same genes are expressed at each stage, but the age and number of cells accounts for the minor morphological differences.
46)
A mutation in aHox gene typically results in A) development ofnormal body parts in abnormal places. B) faulty developmentof the cellular blastoderm. C) cleavagedisruption. D) legs growing out of the head of a fly.
47) The Drosophila homeotic genes typically contain the homeobox. The homeobox is a sequence of 180 nucleotides. The number of amino acids coded for by this sequence is A) 30. B) 60. C) 90. D) 120 E) 180.
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48) The finding that homeotic genes are present in both mammals and insects indicates that these genes must A) control the same traits. B) be on the same chromosomes. C) have arisen very early in the evolutionary history of animals. D) have developed independently and simultaneously. E) have been transmitted into mammals by an insect bite.
49)
Heterochrony is a change in development based on A) changes in the location of where genes are being expressed. B) changes in how much protein is produced. C) changes in the structure of the protein being produced. D) changes in the timing of gene expression.
50) _________blank are cell adhesion proteins that some cells use in the process of differentiation during development. A) Cadherins B) Glycospheres C) Receptors D) Phospholipids
51)
Cells that are programmed to die, shrivel and shrink in a process called A) apoptosis. B) necrosis. C) totipotency. D) induction. E) encoded death.
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52) Cells that die of injury usually swell and then burst. Their contents are released into the extracellular fluid. This form of cell death is referred to as A) apoptosis. B) necrosis. C) toti-latency. D) induction. E) encoded death.
53)
Describe the apoptotic pathway in mammalian cells.
A) Apaf1 inhibits Bcl2, Caspase-8 or -9 is activated, caspases degrade cell components B) Bcl2 activates Apaf1, Caspase-8 or -9 is inhibited, caspases degrade cell components C) Cytoplasmic inhibitors inhibit Bcl2, Apaf1 activates Caspase-8 or -9, caspases degrade cell components D) Cytoplasmic inhibitors inhibit Apaf1, Bcl2 activates Caspase-8 or -9, caspases degrade cell components
54)
In C. elegans ced-9/ced-3 double mutants A) 131 cells always die. B) all 1090 cells die. C) all 1090 cells live. D) only 959 cells live.
55)
The term neoplasia refers to cell accumulation. Neoplasia can be caused by A) increased apoptosis. B) decreased apoptosis. C) blood clots. D) cell membraneinteractions.
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56) You created a worm that expresses a human Bcl-2 transgene, and you are crossing the transgene into a homozygous ced-9 mutant background. However, you inadvertantly used a clone of Bcl-2 with a mutation in the BH domain, which is essential for function. What results do you expect for the ced-9 mutants with the mutant Bcl-2 transgene? A) 131 cells will die. B) All 1090 cells will die. C) All 1090 cells will live. D) 959 cells will die.
57) You have discovered a new gene similar to an integrin. If you misexpress this gene in the wrong tissue early in development, what is a likely phenotype? A) Migration into the wrong area B) Apoptosis C) Homeotic transformation D) Defects in anterior-posterior patterning
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Answer Key Test name: Chap 19_13e_Raven 1) TRUE 2) [B, C, D, E] 3) [A, B]
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Clarify Question • What is the key concept addressed by the question? o This question addresses FGF induction. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o Tunicates are marine invertebrates also known as sea squirts. o The vegetal marginal cells lie on the edge of the vegetal pole and can respond to the FGF signal, and eventually make either mesenchyme or notochord. Gather Content • What do you already know about FGF induction? o The example of induction in the vegetal marginal cells of tunicates illustrates how different cells can have different responses to the same inductive signal, depending on what other genes are active in the cell. o If the vegetal marginal cells receive the FGF signal, and also have the Macho-1 gene expressed, those cells will become mesenchyme. o If the vegetal marginal cells receive the FGF signal, but do not have the Macho-1 gene expressed, those cells will become notochord. o If the cells did not receive the FGF signal, they would become either muscle or nerve cord. Consider Possibilities • Consider the different answer options. Which can you rule out? o Would cells lacking FGF receptor fail to make muscle or nerve cord? No, because those normally result when the FGF signal is NOT received. Version 1
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If the cells lacked the FGF receptor, they would not be able to receive the FGF signal, and would develop as if there were no signal. o They would not be able to develop into the fates that depend on the FGF signal – notochord and mesenchyme. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked which cells would fail to develop if the tunicate vegetal marginal cells lacked FGF receptor. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that the two cell fates that depended on FGF were mesenchyme and notochord? 4) [B, C, D] 5) [A, B, D] 6) [A, B, E]
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Clarify Question • What is the key concept addressed by the question? o This question addresses Hox genes. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o Hox genes are the homeotic genes, found in all animals, that specify anterior-posterior development. o The last common ancestor of invertebrates and vertebrates is an organism that existed ~500 million years ago, before the lineages split. It was a worm-like marine creature. Gather Content • What do you already know about Hox genes? o Hox genes are homeotic genes that specify anterior-posterior development. o The genes contain a homeobox, that encodes a DNA-binding homeodomain. o The genes are organized in clusters in the genome, in order according to their expression pattern from head to tail. o Mice have four copies of the cluster, but flies only have one. o Mutating Hox genes often results in phenotypes of body parts growing in the wrong place. Consider Possibilities • Consider the different answer options. Which can you rule out? o Would the Hox genes of the last common ancestor have mutated to produce an extra pair of wings and legs growing from the head? No, Version 1
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because the last common ancestor didn’t have wings! o Would they have been in four clusters? No, mice have four clusters but flies and many other animals do not. o Would they have contained a MADS-box? No that is from a different set of genes, in plants. o Would the last common ancestor have been too primitive to have Hox genes? No. The Hox genes of other animals must have originated very early in animal evolution. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Would the Hox genes of the last common ancestor have contained homeoboxes? Yes, because they do in flies, mice, and other animals. o Would they have specified anterior-posterior development? Yes, because they do in flies, mice, and other animals. o Would they have been in anterior-posterior order on the chromosome? Yes, because they are in flies, mice, and other animals. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what you can guess about the Hox genes in the common ancestor of flies and mice. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that you can assume the ancestor probably had all the features that are shared between flies and mice, but not the unique Version 1
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ones? 7) [B, C] 8) A 9) B 10) C During early cleavage, the cells divide but do not grow. With each division, the daughter cells are smaller than the previous generation of cells. 11) A 12) C 13) C 14) A 15) D 16) B 17) C 18) A 19) A 20) B 21) C 22) B
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Clarify Question • What is the key concept addressed by the question? o This question addresses determination and differentiation. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o A muscle precursor cell is a cell that has become commiteed to becoming a muscle cell, but has not yet become a muscle cell. o The MyoD1 gene is the gene expressed by muscle precursor cells. It encodes a transcription factor that binds to the promoters of muscledetermining genes to initiate the changes into a muscle cell. Gather Content • What do you already know about determination and differentiation? o The process of determination commits a cell to a particular developmental pathway prior to its differentiation. o Differentiation is the process where gene expression leads to permanent changes in cell structure and morphology. Consider Possibilities • Consider the different answer options. Which can you rule out? o Would you call a muscle precursor cell differentiated? No, because that would mean that it has developed into the final cell morphology. o Would you call it pluripotent? No, because that would mean it could turn into a variety of cell types. o Would you call it totipotent? No, because that would mean it could turn into any cell type. Version 1
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Would you call a muscle precursor cell determined? Yes, because that means that it is committed to a developmental path but not yet differentiated. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked how to describe a muscle precursor cell. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that since a muscle precursor cell is committed to becoming a muscle, it is not pluripotent or totipotent? o Did you realize that since a muscle precursor cell is not yet turned into a muscle cell, it is determined but not yet differentiated? 23) B
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Clarify Question • What is the key concept addressed by the question? o This question addresses determination. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o Transplantation is the process of removing cells from one specimen, and inserting them into a new spot on another specimen. o Determination is the process of a cell committing to a particular cell fate. Gather Content • What do you already know about determination? o When a cell is determined, it is expressing genes that commit it to developing according to a particular cell fate. Consider Possibilities • What other information is related to the question? Which information is most useful? o If the wing cells are not yet determined, they are not yet committed to becoming wing cells. o They will likely respond to signals in the leg that determine leg cell identity. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o The transplanted cells will likely develop as leg cells. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what would become of transplanted cells that were transplanted before they became determined. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that since the cells were not yet determined, they would likely take on the fate of the new location? 24) D
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Clarify Question • What is the key concept addressed by the question? o This question addresses FGF induction. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o Tunicates are marine invertebrates also known as sea squirts. o The vegetal marginal cells lie on the edge of the vegetal pole and can respond to the FGF signal, and eventually make either mesenchyme or notochord. Gather Content • What do you already know about FGF induction? o The example of induction in the vegetal marginal cells of tunicates illustrates how different cells can have different responses to the same inductive signal, depending on what other genes are active in the cell. o If the vegetal marginal cells receive the FGF signal, and also have the macho-1 gene expressed, those cells will become mesenchyme. o If the vegetal marginal cells receive the FGF signal, but do not have the macho-1 gene expressed, those cells will become notochord. o If the cells did not receive the FGF signal, they would become either muscle or nerve cord. If they have macho-1 expressed, they become muscle. If not, they become nerve cord. Consider Possibilities • Consider the different answer options. Which can you rule out? o Would cells lacking FGF receptor and Macho-1 develop into mesenchyme? No, because mesenchyme requires FGF and Macho-1. Version 1
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o Would they develop into muscle? No, because mesenchyme requires Macho-1. o Would they develop into notochord? No, because mesenchyme requires FGF. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If the cells lacked the FGF receptor, they would not be able to receive the FGF signal, and would develop as if there were no signal. o If they lacked Macho-1, they would develop as if that signal was missing. o Would cells lacking FGF receptor and Macho-1 develop into nerve cord? Yes, because nerve cord is the normal outcome when those signals are missing. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked how cells would develop if the tunicate vegetal marginal cells lacked FGF receptor and Macho-1. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that the cell fate that resulted in the absence of FGF and Macho-1 signaling was nerve cord? 25) D 26) D 27) B Version 1
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28) A 29) A 30) D 31) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses reproductive cloning. • What type of thinking is required? o This question is asking you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. • What key words does the question contain and what do they mean? o In this case, cloning refers to reproductive cloning – growing a new individual from a cell. Gather Content • What do you already know about cloning? o Cloning of Dolly was the first example of reproductive cloning. Consider Possibilities • Consider the different answer options. Which can you rule out? o Did Dolly’s cloning demonstrate that the key to cloning success is to pick a donor cell from very early in development? No, actually the cell used was a mammary cell from a six-year old sheep. o Did the cloning demonstrate that genetic imprinting, which occurs in adult reproductive tissue, can take months for sperm and years for eggs? No, it did not address this issue. o Did it demonstrate that cloned animals are capable of producing normal offspring? Yes, she did have offspring. But this was not the most important aspect of Dolly’s cloning. Choose Answer • Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer? o Did Dolly’s cloning demonstrate that the nucleus of a fullydifferentiated cell can be reprogrammed to be totipotent? Yes, this was the most important conclusion from the cloning of Dolly. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what the most significant finding was from the cloning of Dolly. o The question required you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. o Did you recognize that Dolly’s cloning demonstrated that a differentiated cell’s nucleus could be made totipotent? 32) A 33) A 34) C 35) D 36) C 37) E 38) E 39) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses maternal genes. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o The bicoid gene is a maternal gene that specifies the anterior end of the fly embryo. Gather Content • What do you already know about maternal genes? o Maternal genes like bicoid are unusual because they are expressed in the nurse cells of the ovary, not in the embryo itself. o The nurse cells deposit bicoid mRNA into the anterior end of the fly egg where it becomes anchored. o Bicoid protein is necessary to determine anterior development of the embryo. o So if the mother is mutant, the progeny exhibit the phenotype, whether or not they are homozygous for the mutation. Consider Possibilities • Consider the different answer options. Which can you rule out? o Can we conclude that the embryo with the phenotype is genetically wild-type, but has a bicoid mutant mother? No, we cannot determine the genotype of the embryo at all. o Can we conclude the embryo is mutant for bicoid and has a bicoid mutant mother? No, we cannot determine the genotype of the embryo at all. Version 1
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o Can we conclude the embryo can be either genetically wild-type or mutant for bicoid and therefore the genotype of the mother cannot be determined from the information provided? No, in fact the genotype of the mother must be homozygous mutant for bicoid. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If the individual fly embryo has the bicoid mutant phenotype, we can conclude that it may be either genetically wild-type or mutant for bicoid, but definitely has a bicoid mutant mother. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what you can conclude about a fly embryo that has the bicoid mutant phenotype. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that as a maternal gene, the phenotype of an embryo reflects the genotype of the mother, not the embryo itself. 40) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses the gene bicoid, and its protein product, Bicoid. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o b icoid is a gene that is necessary for specifying anterior development. o Bicoid (note the formatting difference) is the protein product of the bicoid gene. Gather Content • What do you already know about bicoid? o b icoid is a gene that is expressed in the nurse cells of the ovary, then mRNA is deposited into the anterior of the egg, where it leads to production of Bicoid protein and anterior development. Consider Possibilities • Consider the different answer options. Which can you rule out? o If Bicoid was injected, would the embryo try to form posterior structures in the middle of its body? No, that doesn’t make sense because bicoid specifies anterior structures. o If Bicoid was injected, would the embryo not develop at all? No, the cells would just develop according to the signals they received. Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If Bicoid was injected, would the embryo try to form anterior structures in the middle of its body? Yes, because the cells in the middle would receive the anterior-specifying morphogen. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what would happen if you injected Bicoid into the middle of an embryo. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that Bicoid would induce determination of anterior structures? 41) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses caudal. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o c audal is a gene that specifies posterior development in the Drosophila embryo. o b icoid is a gene that specifies anterior development. Gather Content • What do you already know about caudal? o Caudal protein activates genes required for the development of posterior structures. o The caudal mRNA is evenly distributed across the egg, but the protein becomes localized, because Bicoid protein binds to and inhibits translation of caudal mRNA. o Therefore, caudal is only translated in the posterior regions of the egg where Bicoid is absent. Consider Possibilities • Consider the different answer options. Which can you rule out? o Would overexpression of caudal interfere with the development of posterior structures? No, it normally specifies posterior structures. o Would overexpression interfere with the development of both anterior and posterior structures? No, just anterior – it normally specifies posterior structures. o Would it have no effect since the cytoplasm has already been Version 1
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determined? No, it is a powerful morphogen so it would have a disruptive effect. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Would overexpression of caudal interfere with the development of anterior structures? Yes, since caudal specifies posterior development, it would disrupt the development of the anterior. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what would result from overexpression of caudal. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that caudal normally specifies posterior development? 42) C 43) B 44) D
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Clarify Question • What is the key concept addressed by the question? o This question addresses dorsal. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o Drosophila melanogaster is the species of fruit fly used in genetics research. o The gene dorsal specifies ventral development in the Drosophila embryo. Gather Content • What do you already know about dorsal? o The dorsal–ventral axis is established by actions of the dorsal gene product. o Maternal transcripts of the dorsal gene are put into the oocyte, but the dorsal mRNA does not become asymmetrically localized. o Following fertilization, a signaling molecule is differentially activated on the ventral surface of the embryo. o Activation of this pathway results in the selected transport of the Dorsal protein (which is everywhere) into ventral nuclei, forming a gradient along the D/V axis. o The Dorsal protein levels are highest in the nuclei of ventral cells. Consider Possibilities • What other information is related to the question? Which information is most useful? o Note that many Drosophila genes are named for the mutant Version 1
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phenotype that results from a loss of function in that gene. o A lack of dorsal function produces dorsalized embryos with no ventral structures. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Will a lack of dorsal result in a lack of ventral structures? Yes, because the role of dorsal is to specify ventral structures. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what would result from a maternal mutation in the gene dorsal. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that despite the name, dorsal actually specifies ventral development? 45) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses homeotic genes and metamorphosis. • What type of thinking is required? o This question is asking you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. • What key words does the question contain and what do they mean? o Complete metamorphosis refers to the development of insects like flies, moths, and butterflies, where the larva transforms into a completely different looking adult form. Gather Content • What do you already know about homeotic genes and metamorphosis? o In our text, we saw a diagram illustrating how the expression of homeotic genes from head to tail is very similar in both the larva and adult fly. o Even in mice, the basic pattern of expression is similar. o Nevertheless, the morphology of the larva and adult fly are very different. Consider Possibilities • Consider the different answer options. Which can you rule out? o Would you predict that completely different sets of genes must be used in the development of larvae and the adult? No, we know that isn’t true. For instance, we know the homeotic genes are used in both. o Would you predict that the order of homeotic genes along the body axis must be different in larvae and adult? No, we know that isn’t true. The homeotic genes are expressed in the same basic pattern in both. Version 1
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o Would you predict that the same genes are expressed at each stage, but the age and number of cells accounts for the minor morphological differences? No, there must be some gene expression differences to account for the BIG morphological differences. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Would you predict that the basic organization of homeotic genes is the same in both larvae and adult, but the expression of some other genes must be different? Yes, this is the most reasonable prediction. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what you would predict about gene expression in metamorphic insects. o The question required you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. o Did you recognize that the larva and adult of an insect with complete metamorphosis look very different? o Did you remember that the homeotic genes are expressed in the same basic order in both the larva and the adult? 46) A 47) B 48) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses homeotic genes. • What type of thinking is required? o This question is asking you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. • What key words does the question contain and what do they mean? o Homeotic genes are the Hox genes, a set of highly conserved developmental regulatory genes found in all animals. Gather Content • What do you already know about homeotic genes? o The homeotic genes are a set of related genes with several unusual features. o Similar genes are found in all animals, including invertebrates like flies and vertebrates like mice and humans. o They are clustered in the genome, and the order of genes in the cluster is the same as the order of gene expression along the anterior posterior axis. o They are master regulatory genes. When their expression changes due to a mutation, a completely different body part can grow in the wrong place. Consider Possibilities • Consider the different answer options. Which can you rule out? o Since homeotic genes are in both flies and mice, does that mean they control the same traits? No. For instance, Antennapedia controls wing development in flies, but the related gene does not grow wings in mice. o Does that mean they are on the same chromosomes? No, they can be Version 1
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on different chromosomes in different species. In fact, mice have four copies of the whole Hox complex. o Does that mean they developed independently and simultaneously? No, that is not a likely explanation. o Does that mean they were transmitted into mammals by an insect bite? No, that is not likely. Insect bites do not transmit DNA. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Since homeotic genes are in both flies and mice, does that mean the Hox complex arose very early in the evolutionary history of animals? Yes! The Hox genes arose in a common ancestor of vertebrates and invertebrates which, given the long divergence between insects and mammals, was early from an evolutionary perspective. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what it means that insects and mammals share similar homeotic genes. o The question required you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. o Did you recognize that both insects and mammals inherited their homeotic genes from an ancient common ancestor? 49) D 50) A 51) A Version 1
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52) B 53) C 54) C 55) B
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Clarify Question • What is the key concept addressed by the question? o This question addresses apoptosis. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. • What key words does the question contain and what do they mean? o Neoplasia is a broad term that includes cancer and other abnormal cell growths. Gather Content • What do you already know about apoptosis? o Apoptosis occurs when a “death program” is activated. o All animal cells appear to possess such programs. Consider Possibilities • What other information is related to the question? Which information is most useful? o Cells could accumulate due to defective cell death, or apoptosis. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If there was decreased apoptosis, that would result in extra cells, or neoplasia. Reflect on Process • Did your problem-solving process lead you to the correct answer? Version 1
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If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what could cause neoplasia. o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that too little apoptosis would result in abnormally large numbers of cells? 56) B
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Clarify Question • What is the key concept addressed by the question? o This question addresses the apoptosis pathway. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o Bcl-2 is an inhibitor of the apoptosis pathway in mammals. o The worm gene ced-9 is homologous to Bcl-2, and also inhibits the apoptosis pathway. Gather Content • What do you already know about the apoptosis pathway? o In worms, 131 of the 1090 cells normally die by the apoptosis pathway. o If the inhibitor ced-9 is mutant, then all cells die. Consider Possibilities • What other information is related to the question? Which information is most useful? o In a wild-type worm, 131 cells should die. o If the inhibitor ced-9 is mutant, then all cells die. o If that mutant carried a wild-type Bcl-2 transgene, then that would act like ced-9 and the cells would live. But... Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o Since the Bcl-2 transgene is mutant in its critical BH domain, it cannot function and it may as well not be there. o So all 1090 cells will die. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what would result if a mutant Bcl-2 transgene was in a ced-9 background. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that normally the Bcl-2 transgene would rescue the ced-9 mutant, but with a mutation in the BH domain it can’t? 57) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses integrins. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. • What key words does the question contain and what do they mean? o Integrins are proteins that attach to the cytoskeleton and also reach out to bind things in the extracellular matrix. Gather Content • What do you already know about integrins? o Integrins are attached to actin filaments of the cytoskeleton and protrude out from the cell surface in pairs, like two hands. The “hands” grasp a specific component of the matrix, such as collagen or fibronectin, thus linking the cytoskeleton to the fibers of the matrix. o In addition to providing an anchor, this binding can initiate changes within the cell. o Cell migration is largely a matter of changing patterns of cell adhesion. As a migrating cell travels, it continually extends projections that probe the nature of its environment. Tugged this way and that by different tentative attachments, the cell literally feels its way toward its ultimate target site. Consider Possibilities • Consider the different answer options. Which can you rule out? o Are integrins often associated with apoptosis? No, we learned about other genes in the apoptotic pathway, like Bcl-2 or the ced genes. o With homeotic transformation? No, we learned about other genes that Version 1
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cause homeotic transformation – the Hox genes. o With defects in anterior-posterior patterning? No, we learned about other genes that control AP patterning, like bicoid and nanos. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Are integrins often associated with cell migration? Yes. We learned how blocking integrins could block cell migration. It makes sense that misexpression could lead cells to migrate to the wrong place. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked what might result from misexpression of integrins. o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that misexpression of integrins might lead cells to migrate toward signals in the wrong place?
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Chapter 20 13e CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 1) Select the examples that can be described as intersexual selection. A) A female swordtail fish chooses a male with the longest tail. B) Two male elk are battling to control a territory. C) Two females are fighting for the best nesting site. D) A peahen chooses a mate with the most eyespots in his tail feathers. E) A male stickleback fish chooses the largest female as a mate.
2) The Human Genome Project sequenced the human genome and created a single reference genome that is a useful online tool for researchers. Recent studies have shown that humans have significant genetic variability, with a typical person varying 3% from the reference genome. Based on this, what TWO things could a researcher do to improve their work in finding cures for disease? A) Look for a correlation between SNPs and occurrence of the disease. B) Test possible cures in people of different genetic backgrounds. C) Focus on just the reference genome, to keep experiments simple. D) Choose a genome that represents the population most likely to pay for a drug. E) Exclude patients with unusual genomes from research studies.
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 3) When the function of an allele is influenced by the alleles of other genes elsewhere in the genome, the interaction is called _________blank and can affect selection for the allele. A) epistasis B) incomplete dominance C) frequency-dependent selection D) pleiotropy E) double inheritance
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4)
By evaluating and selecting mates with superior qualities, an animal can increase its A) reproductive success. B) learning. C) competitive strategies. D) foraging efficiency. E) length of life.
5)
Natural selection for a certain phenotype will affect the _________blank . A) allele frequency of a population B) allele frequency of an individual C) genotype of an individual D) genotype of a population
6) When fisheries managers move fish from one lake to another, this causes gene_________blank. A) blending B) flow C) mutation D) dominance
7) Genotypes are said to be in_________blank equilibrium if there is random mating and no other forces tend to alter the proportions of alleles from one generation to the next. A) steady state B) homeostatic C) Hardy-Weinberg D) Mendelian E) frequency-dependent
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8) The presence of the disease sickle cell anemia illustrates that natural selection does not always eliminate_________blank alleles. A) dominant B) recessive C) polymorphic D) neutral E) epistatic
9) As a mechanism of evolution, natural selection acts on variants within populations and ultimately leads to different species. This was proposed by A) Mendel. B) Lyell. C) Malthus. D) Darwin. E) Founder.
10)
In the Hardy-Weinberg equation,p andq are_________blank. A) allelefrequencies B) genotypes C) phenotypes D) measures offitness E) mutation rates
11) A restriction in genetic variability caused by a drastic reduction in population size is called a
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A) founder effect. B) Hardy-Weinberg effect. C) bottleneck effect. D) polymorphic effect. E) adaptive effect.
12)
Reproductive success of an individual is known as: A) variation. B) microevolution. C) macroevolution. D) fitness. E) adaptive makeup.
13)
Darwin proposed that natural selection occurs in an environment by
A) favoring heritablefeatures that make the organism better suited to survive and reproduce. B) producing a constant number of offspring while in that environment. C) surviving for a fixed amount of time. D) resisting the environment and keeping the environment from changing. E) favoring those individuals with the most favorable acquired characteristics.
14)
The frequency of a particular allele within a population can be changed, over time, by A) genetic outflow. B) large population size. C) selection. D) inheritance of acquired characteristics. E) random mating.
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15) The preservation of genes that increase the likelihood of survival and reproduction of some individuals within a population is called the process of A) natural selection. B) creation of new species. C) genetic drift. D) outcrossing. E) increasing evolutionary resistance.
16) There are more than 30 blood group genes in humans, in addition to the ABO locus, each with multiple alleles. This increases ____ in human populations. A) geneticvariability B) homozygosity C) selectivemating D) gene flow E) foundereffects
17) Two parents who do not have sickle cell anemia have a child that has the disease. The parents are both: A) homozygous for the sickle cell allele. B) heterozygous for the sickle cell allele. C) homozygous for the normal allele. D) epistatic for the sickle cell allele. E) pleiotropic for the sickle cell allele.
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18) In the graph above, how can the change in infant mortality be explained as birth weight increases from 2 to 7 pounds? A) A 3 pound baby will have more optimal development and lowest mortality. B) A baby closer to 7 pounds will not be able to be delivered safely and thus have higher mortality. C) A baby closer to 7 pounds will need more oxygen and thus have higher mortality. D) A baby closer to 7 pounds will have more developed organs and thus have lower mortality. E) A 2 pound baby will not be able to be delivered safely and thus have lower mortality.
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19) In the graph above, which baby characteristics would explain the percent infant mortality curve and any subsequent effects on fitness?
A) The baby needs to be large enough to survive after birth, but small enoughfor a safe delivery. B) The larger the babythe better the chance of survival. C) The smaller thebaby the better the chance of survival. D) The baby needs tobe small enough to survive after birth, but large enough for a safedelivery. E) There is no correlation between birth weight and survival.
20) Hardy-Weinberg pointed out that the original proportions of the genotypes in a population would remain constant from generation to generation if certain assumptions are met. Which one of the following is NOT a Hardy-Weinberg condition?
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A) The population isvery large. B) No gene flow occurs. C) No selection occurs. D) Random mating occurs. E) No polymorphic loci exist in the population.
21) For a gene with two alternative alleles, A (with a frequency of p) and a (with a frequency of q), the term in the algebraic form of the Hardy-Weinberg equilibrium for the heterozygote genotype frequency is A) p2. B) q2. C) 2pq. D) (p+q)2. E) 2Aa.
22) The observation that many Native Americans have type O blood is best explained by_________blank A) founder effect. B) gene flow. C) frequency-dependent selection. D) assortative mating. E) frequentmutations.
23) Female cardinals select male mates in part based on their bright red color. What effect would this have on a cardinal population?
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A) The frequency ofred alleles would be greater than those predicted by HardyWeinbergequilibrium. B) The frequency ofred alleles would be less than those predicted by HardyWeinbergequilibrium. C) The red allelefrequencies would remain unchanged because of equilibrium. D) The frequency of red alleles would be equal to those predicted byHardy-Weinberg equilibrium. E) The red allelefrequencies would decrease because of equilibrium.
24) You spray your kitchen with an insecticide to kill the cockroaches. A few survive and reproduce, producing a large healthy population in a few generations that all have similar genetic backgrounds. This is an example of_________blank A) mutation. B) migration. C) assortative mating. D) bottleneck effect. E) gene flow.
25) Gene flow, defined as the movement of genes from one population to another, can take place by migration, as well as A) mating with certain trait-containing individuals. B) mating with dominant phenotypes. C) mating betweenindividuals of adjacent populations. D) physical movement of genes within an individual by transposons. E) mating with recessive phenotypes.
26) Some flowering plants cannot self-pollinate which increases their tendency to mate with phenotypically different mates, a process called disassortative mating. What effect would this have on a population, compared to expectations based on the Hardy-Weinberg principle?
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A) An increase in heterozygotes would be observed. B) A decrease inheterozygotes would be observed. C) An increase inhomozygotes would be observed. D) No changehomozygotes or heterozygotes would be observed. E) The populationwould remain in Hardy-Weinberg equilibrium.
27)
_________blank would keep a population in Hardy-Weinberg equilibrium. A) Mutation B) Gene flow C) Random mating D) Genetic drift E) Selection
28) Being born with extra fingers on a hand is called polydactyly. This is more common in some populations in North America than others due to_________blank. A) a founder effectbecause their ancestors from Europe carried the alleles B) an increase inmutation rate in these populations C) random mating withother populations in North America D) natural selectionin favor of extra fingers in these populations E) migration of people with multiple fingers out of the population
29) In order for natural selection to occur within a population, certain conditions must be met. One condition is A) phenotypic differences resulting from environmental conditions. B) frequentmutations that are inherited. C) low rates of immigration. D) phenotypic variations that are genetic. E) heterozygosity must be very low.
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30) About 80% of the alleles present in thoroughbred horses can be dated back to 31 known ancestors from the late eighteenth century. As a result, one would expect_________blank A) low rates of mutation. B) many polymorphic alleles. C) little variation to select upon. D) Hardy-Weinberg equilibrium. E) random mating.
31) In a forest, trees that grow taller get more sunlight and gain more energy than other nearby trees. This results in_________blank A) natural selection. B) stabilizingselection. C) disruptive selection. D) directional selection. E) artificial selection.
32) For a gene with two alternative alleles, B and b, the term q2 in the Hardy-Weinberg equation represents A) the frequency of the B allele. B) the frequency of the bb genotype. C) the total number of individuals in the population. D) the frequency of the Bb genotype. E) the total number of alleles for that gene in the population.
33)
Cheetahs have been through a genetic bottleneck; evidence for this is that
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A) little naturalselection occurs in this species. B) the body is long, thin, and graceful. C) there is very little genetic variability. D) these cats are members of an endangered species. E) they originally came from small areas of Africa.
34) Animals that select mates that are phenotypically similar will have_________blank when compared with Hardy-Weinberg predictions. A) fewerhomozygotes B) less naturalselection C) moreheterozygotes D) more homozygotes. E) more mutations
35) If a population was in Hardy-Weinberg equilibrium, then _________blank would occur in that population. A) directionalselection B) assortative mating C) naturalselection D) anincrease of recessive alleles E) no evolutionarychanges
36) Ear size is a variable trait in a certain mouse species. A few mice homozygous for the large-ear allele happened to arrive on an island that already contained a population of smalleared mice. This is an example of _________blank A) a bottleneckeffect. B) gene flow. C) increasedmutation. D) genetic drift. E) naturalselection.
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37) A certain island is the home of sea birds that migrate, as well as ground-dwelling birds that stay on the island. The ground-dwelling birds are more likely to be in Hardy-Weinberg equilibrium than the sea birds, because: A) of highimmigration in the sea bird population. B) the sea birds are more exposed to UV light. C) there are fewermutations in the sea birds. D) mating is random in the sea birds. E) natural selection is stronger in the ground-dwelling birds.
38) The percentage of different colored water boatmen eaten by fish were graphed relative to the frequency of that color in the population. Based on the graph, a population of water boatmen would _________blank A) lose raregenotypes. B) have no variationin genotype frequencies. C) increase in raregenotypes. D) increase insize. E) decrease in geneticvariability.
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39) In some instances environmental change causes a situation where one phenotype is favored for a period of time, and then a different phenotype is favored. This oscillating selection causes A) the maintenance of genetic variation in the population. B) elimination of rarer genotypes because of uneven selection. C) an increase in point mutations. D) high population increase to maintain phenotypic variation. E) extinction of the population.
40) People homozygous for the sickle-cell anemia allele develop a life-threatening disease, while those homozygous for the normal allele are at the highest risk of dying from malaria. Carriers have some resistance to malaria but do not develop sickle cell anemia. This is an example of_________blank A) founder effect. B) genetic bottleneck. C) point mutation. D) heterozygote advantage. E) heterozygosity.
41)
In disruptive selection, over time
A) a population goes extinct. B) the most extreme outliers of a population are eliminated (e.g., the largest beaks and smallest beaks are eliminated). C) the population is strongly selected for in one direction (e.g., larger beak size). D) the population is strongly selected for in two directions (e.g., larger beak size and smaller beak size). E) a population increases its variation (e.g., a wide selection of all beak sizes).
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42) During a drought on the Galapagos islands, finches with larger beaks were able to crack the large tough seeds produced by plants that survived the dry conditions. This is an example of_________blank. A) directionalselection B) stabilizingselection C) disruptiveselection D) genetic drift E) a foundereffect
43) If the frequency of an autosomal recessive trait in humans is 1 out of 100 births, what would be the expected frequency of heterozygote carriers for the trait if we assume that the gene is in Hardy-Weinberg equilibrium? A) 0.01 B) 0.10 C) 0.18 D) 0.81 E) 0.90
44) The recessive phenotype of a trait occurs in 16% of a population. What is the frequency of the dominant allele? A) 0.16 B) 0.36 C) 0.40 D) 0.48 E) 0.60
45) A human autosomal recessive trait appears in 1 in 100 births. What percent of people are homozygous dominant for this gene?
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A) 1% B) 10% C) 18% D) 81% E) 90%
46) A population of flowers is in Hardy-Weinberg equilibrium with an allele frequency for white flowers ( w) of 40%. What percentage of the flowers will have the colored or dominant phenotype? A) 16% B) 25% C) 40% D) 60% E) 84%
47) In a large population of randomly reproducing rabbits, a recessive allele r comprises 80% of the alleles for a gene. What percentage of the rabbits would you expect to have the recessive phenotype? A) 4% B) 32% C) 64% D) 80% E) 100%
48) A population of geese has two color phenotypes, brown and gray. Color is controlled by a single gene, with the brown allele dominant. A random sample of 250 geese finds that 210 are brown. What percentage of geese are heterozygous? (Assume that the population is in HardyWeinberg equilibrium.)
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A) 36% B) 43% C) 48% D) 57% E) 84%
49) Coloration in the peppered moth (Biston betularia) is determined by a single gene with two alleles showing complete dominance. Dark moths are homozygous dominant or heterozygous for the gene, light moths are homozygous recessive. In a sample of 100 moths, you determine that 64 of the moths are dark. According to the Hardy-Weinberg rule, the expected frequency of the dominant allele is ___. A) 0.4 B) 0.36 C) 0.6 D) 0.64 E) It cannot be determined.
50) Antigens on red blood cells are hereditary traits that allow blood to be typed in different ways. One system is based on a gene with two alleles, M and N. If the frequency of the M allele in a population is 0.4, then according to the Hardy-Weinberg rule, the expected frequency of the heterozygous MN genotype is_________blank. A) 0.16 B) 0.24 C) 0.36 D) 0.48 E) 0.6
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51) The disease sickle-cell anemia is common in malaria-infested areas because individuals that are heterozygous for the gene (AS) have enhanced resistance to malaria compared to other individuals (AA). Individuals with severe sickle-cell anemia (SS) often die before reproduction. If this population moves to an area without malaria, what will happen to the allele frequency of the A allele over time? A) It will go upbecause there is no malaria. B) It will go upbecause there is no sickle cell anemia. C) It will go downbecause there is no malaria. D) It will go downbecause there is no sickle cell anemia. E) It will go down because there are diseases of some kind everywhere.
52)
Which factor does NOT result in gene flow? A) Wind-blownpollen B) Gametes dispersedby ocean currents C) Zygotes dispersedby ocean currents D) Disassortative mating within a population E) Hybridizationbetween neighboring populations
53) The California populations of the Northern elephant seal are descendants from a very small population of seals that was overhunted in the 1890s. Heterozygosity in this population would be expected to be_________blank due to_________blank. A) low; a bottleneck effect B) low; the Hardy-Weinberg effect C) great; disruptive selection D) great; a bottleneck effect E) great; assortative mating
54) Different species of picture-winged fruit flies in the Hawaiian Islands are genetically similar to each other, yet genetically different from their ancestral population in Asia. This is probably an example of_________blank
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A) sexual selection. B) directional selection. C) disruptive selection. D) founder effect. E) gene flow.
55) An insect population that becomes resistant to a plant's toxin is an example of_________blank. A) naturalselection B) genetic drift C) disruptiveselection D) a foundereffect E) gene flow
56)
The organism with the highest fitness is: A) An animal thatlives 10 years and produces 10 offspring per year. B) An animal thatlives 100 years and produces 10 offspring total. C) An animal thatlives 2 years and produces 10 offspring per year. D) An animal thatlives 10 years and produces 2 offspring per year. E) An animal thatlives one year and produces 10 offspring total.
57) A population of lizards lives in a rocky area next to a desert. Some lizards are lightcolored and blend into the sand. Others are dark and blend into the rocks. What may happen to this population of lizards over time? A) They may evolveinto two separate species as a result of disruptive selection. B) They may evolveinto two separate species as a result of directional selection. C) They may remainone species as a result of disruptive selection. D) They may remainone species as a result of directional selection. E) They may remainone species as a result of stabilizing selection.
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58) In the experiment above, guppy color patterns (spots) were measured in populations exposed to increasing amounts of predation. From this you could conclude that _________blank . A) predators aremore likely to catch and eat brightly colored guppies B) predators areless likely to catch and eat brightly colored guppies C) brightly coloredguppies are more likely to reproduce in the presence of predators D) predators do notaffect the color patterns of guppies E) evolutionarychanges take millions of years to appear
59)
Both extremes of an array of phenotypes are favored in_________blank . A) directionalselection B) stabilizingselection C) disruptive selection D) gene flow E) genetic drift
60) In the early ancestors of the modern giraffe, longer necks allowed animals to reach higher tree branches as food. This would lead to_________blank in the ancestral giraffe population. Version 1
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A) directionalselection B) stabilizing selection C) disruptive selection D) sexualselection E) genetic drift
61)
The midrange of an array of phenotypes is favored in_________blank. A) directionalselection B) stabilizing selection C) disruptive selection D) gene flow E) genetic drift
62)
Based on the graph above, the color of male guppies can be seen as a balance between positive and negative selections. Bright colors are an advantage in _________blank, but a disadvantage in _________blank.
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A) attracting mates;avoiding predators B) avoidingpredators; attracting mates C) avoidingpredators; finding food D) attracting mates;finding food E) finding food;attracting mates
63) Many male songbirds are brightly colored. However, the color of the birds is determined by a balance of A) natural selectionagainst bright colors by predation and sexual selection in favor of brightcolors. B) mutations thatreduce bright colors and gene flow in favor of bright colors. C) natural selectionagainst bright colors by predation and mutations that introduce brightcolors. D) mutations thatreduce bright colors and sexual selection in favor of bright colors. E) gene flow that reduces bright colorsand natural selection in favor of bright colors.
64) In a research study, seed production was measured for a plant that has variation in flower petal size. The researchers hypothesized that larger petals would better attract pollinators and result in higher fitness. Does the data support this hypothesis? Small petals
Medium petals
Large petals
Average seed #
20
25
15
Relative fitness
0.8
1.0
0.6
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A) No, because plants with small and medium petals had higher relative fitness. B) No, because plants with small petals had the highest relative fitness. C) Yes, because plants with large petals had the highest relative fitness. D) Yes, because plants with large petals had fewer seeds.
65) Since females take on the larger parenting role in most species, what tendency do they have? A) They produce large numbers of gametes. B) They compete heavily for access to high fitness males. C) They are the choosy sex. D) They acquire polyandrous groups of male mates. E) They fight for territory.
66) Pea fowl (peacocks and peahens) show sexual dimorphism -- males have long blue-green tail feathers with eyespots, while females have short brown tail feathers. Which statement best summarizes the graphed data about peacocks?
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A) There are no peacocks with less than 140 eyespots. B) The fewer eyespots that a peacock has in his tail, the more mates he attracts. C) Eyespots have no correlation with the ability to attract a mate. D) The more eyespots that a peacock has in his tail, the more mates he attracts. E) There are no peacocks with more than 165 eyespots.
67) A study finds a positive correlation between the number of spots on the tails of male peacocks and their mating success. What would be the best follow-up experiment to test causation? A) Count the number ofspots on female tails and measure mating success. B) Remove spots or addartificial spots to male tails and determine female responses. C) Measure the spermcount of males and compare to spot count. D) Inject testosteroneand observe changes in spot count.
68) Platys and swordtails are related tropical freshwater fish. In studies, researchers have shown that female platys prefer males with swordtails, even though males of their own species do not have them. This was discovered by attaching artificial swordtails to platy males. What does this suggest about the origin of the swordtail feature? A) Female preferencefor swords may have predated the origin of the feature itself. B) Evolution of swords later led to evolution of female preference forswords. C) The same gene thatcauses sword development also causes development of neural circuits for femalepreference. D) Adjacent genes onthe same chromosome cause sword development and development of neural circuitsfor female preference.
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69) Male Mormon crickets choose larger females as their mates. Which of the following statements best interprets the graph?
A) Larger females live longer and thus produce more eggs. B) Larger females are capable of storing sperm. C) Larger females reproduce earlier than smaller females. D) Larger females lay more eggs. E) Larger females defend themselves better.
70) In the phalarope, or wade pipes bird, the male is unusual in playing the larger parenting role -- he performs all the egg incubation and chick care. What unusual behavior might you predict for the female of the species? A) The female providessperm to fertilize the male's eggs. B) The female is partof a large harem of females, under the domain of a single male. C) The females competeto mate with the males, who choose among them. D) The females havedull, brown coloring that keeps them well-camouflaged.
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71) A bird species is under selection pressure for a trait that helps them tolerate toxins in the environment. If there are approximately equal numbers of birds with and without the trait in a small, isolated population, genetic drift will A) act to increase the ratio of birds with the toxin-tolerance. B) act against the direction of natural selection. C) act to decrease the ratio of birds with the toxin-tolerance. D) act randomly with respect to the trait. E) reduce the overall number of birds.
72) A researcher wants to study an example of natural selection while it is happening. He finds a toxic spill that caused selection for resistance traits in species nearby. Which type of species should he focus on, to best minimize the counteracting effects of gene flow from outside the spill site? A) Wind-pollinated plant B) Bird C) Deer D) Human E) Slug
73) Often, antlers are used for fighting between males, to win territory and mates. But the antlers of the Irish Elk were so massive that they would have made fighting difficult. Instead they may be due to_________blank, from females who preferred males with the largest antlers. A) intrasexual selection B) oscillating selection C) parental investment D) stabilizing selection E) intersexual selection
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Answer Key Test name: Chap 20_13e_Raven 1) [A, D, E] 2) [A, B]
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Clarify question: ● What is the key concept addressed by the question?● This question relates to human genetic variation, from the textbook section on genetic variation and evolution. ● What type of thinking is required?● This is an evaluate question, because you are asked to consider the implications of variation on medical research, and make a judgement about the best course of action. Gather Content: ● What do you already know about genetic variation? What other information is related to the question? ● Like other animals whose genomes have been studied in large numbers, humans have a surprising amount of genetic variation. That means that there is not "one" human genome, but many. This will affect how a researcher thinks about health and disease, because each person's DNA and proteins will be a little different. Some people may be more likely to have a disease because of their unique genes, and some drugs or treatments may work differently because of people's differing genetic profiles. Choose Answers: ● Given what you now know, what information is most likely to produce the correct answer?● The answers are "Look for a correlation between SNPs and occurrence of the disease." and "Test possible cures in people of different genetic backgrounds." ● By looking for a correlation between SNPs (single nucleotide polymorphisms) and disease, a researcher may discover that a particular genetic profile contributes to a disease. And by testing possible cures in a variety of people, they may discover that a treatment works for some people, even if it doesn't work well for others.
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Reflection on Process: ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This was an evaluate question. You needed to consider how genetic variation would affect the work of a researcher, and then decide what they should do. Remember that variation in genes causes variation in proteins, and that affects how cells and the body work. That could affect a disease process -- and also affect the reaction to a drug or treatment. 3) A 4) A 5) A 6) B 7) C 8) B 9) D 10) A 11) C 12) D 13) A 14) C 15) A 16) A 17) B
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Clarify Question ● What is the key concept addressed by the question?● The question stem is asking you to determine the genotype of parents when you know the parent’s and offspring’s phenotypes. ● What type of thinking is required?● This question is asking you to take the concept of allele dominance and use, or apply, it to identify genotypes of individuals. ● What keywords does the question contain and what do they mean?● Sickle cell anemia, which refers to a hereditary disease affecting hemoglobin in humans. ● Homozygous, which means that both alleles for a gene are the same. ● Heterozygous, which means that the alleles for a gene are different. ● Epistatic, which is the phenomenon in which an allele for one gene may have different effects, depending on alleles present at other genes. ● Pleiotropic, which means alleles affect multiple aspects of a phenotype. Gather Content ● What do you already know about sickle cell anemia? How does it relate to the question?● The sickle-cell allele is recessive to the normal allele. This means that only individuals that are homozygous recessive will express sickle cell anemia. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Epistasis is the phenomenon in which an allele for one gene may have different effects, depending on alleles present at other genes. In addition, pleiotropic alleles often affect multiple aspects of a phenotype. When would a gene be either epistatic Version 1
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or pleiotropic? Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Recall that Punnett squares may be a useful tool for determining the genotype of parents and offspring. Perhaps the creation of Punnett squares will be a useful tool for determining the genotype of the parents based upon their phenotype. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to determine the genotype of the parents. ● Answering this question correctly depended on your ability to use Mendelian genetics in a new situation. ● If you got the right answer correct, great job! If you got an incorrect answer, where did the process break down? Did you remember how dominant and recessive alleles are expressed as phenotypes? Do you understand the difference between an organism’s genotype and an organism’s phenotype? Did you have trouble extending the application of Punnett squares to answer this question? 18) D
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Clarify Question ● What is the key concept addressed by the question?● This question is asking you to interpret data from a graph and draw a conclusion about a baby’s chances of survival based upon the birth weight. ● What type of thinking is required?● This is an analyze question because you have to interpret a graph to figure out how a baby’s weight is related to its mortality. ● What key words does the question contain and what do they mean?● Mortality, which means being in a state of death. ● Birth weight, which refers to the mass of a newborn. ● Correlation, which refers to a relationship between to two variables. Gather Content ● What do you already know about fitness? How does it relate to the question?● Fitness is defined by an organism’s reproductive success relative to other members of its population. Compare how the percent infant mortality is influenced by the birth weight in pounds. How could an infant’s birth weight influence its ability to survive and eventually reproduce? Consider Possibilities ● What other information is related to the question? Which information is most useful?● Analysis of the graph will allow you to identify the rate of infant mortality based upon their birth weight. During gestation, the developing fetus grows in size. How are the infant’s organs developing during this time? What happens to infant mortality if the infant grows beyond seven pounds? Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● This question requires you to interpret a graph and analyze the data being presented. In this graph there are two sets of data. One is the percent of infant mortality and the other is percent of births in a population. These two sets of data can have no correlation or they be correlated. If they are correlated, then they can have a positive correlation, where both variables can change in the same direction, or they can have a negative correlation where one variable increases while another variable decreases. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you how changes in infant mortality can be explained by
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changes in birth weight. ● Answering this question correctly depended not only on distinguishing between changes in infant mortality and changes in birth weight, but on your ability to break down, or analyze, a graph related to changes in infant mortality and changes in birth weight. ● If you got the correct answer, excellent! If you got an incorrect answer, where did the process break down? Did you remember how two sets of data are related, or that an infant’s development in the womb can influence its mortality and survivability? Did you have trouble breaking down the graph to determine the correct answer?
19) A
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Clarify Question ● What is the key concept addressed by the question?● This question is asking you to interpret data from a graph and draw a conclusion about a baby’s chances of survival based upon the birth weight. ● What type of thinking is required?● This is an analyze question because you have to interpret a graph to figure out how a baby’s weight is related to its mortality. ● What key words does the question contain and what do they mean?● Mortality, which means being in a state of death. ● Birth weight, which refers to the mass of a newborn. ● Correlation, which refers to a relationship between to two variables. ● Fitness, which means the number of surviving offspring left in the next generation. Gather Content ● What do you already know about fitness? How does it relate to the question?● Fitness is defined by an organism’s reproductive success relative to other members of its population. Compare how the percent infant mortality is influenced by the birth weight in pounds. How could an infant’s birth weight influence its ability to grow old enough to reproduce? What might happen if an infant is too large to safely be delivered during birth? Consider Possibilities ● What other information is related to the question? Which information is most useful?● Analysis of the graph will allow you to identify the rate of infant mortality based upon their birth weight. During gestation, the developing fetus grows in size. How are the infant’s organs developing during this time? What happens to infant mortality if the infant grows beyond seven pounds? Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● This question requires you to interpret a graph and analyze the data being presented. In this graph there are two sets of data. One is the percent of infant mortality and the other is percent of births in a population. These two sets of data can have no correlation or they be correlated. If they are correlated, then they can have a positive correlation, where both variables can change in the same direction, or they can have a negative correlation where one variable increases while another variable decreases. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the
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process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you how changes in infant mortality can be explained by changes in birth weight. ● Answering this question correctly depended not only on distinguishing between changes in infant mortality and changes in birth weight, but on your ability to break down, or analyze, a graph related to changes in infant mortality and changes in birth weight. ● If you got the correct answer, excellent! If you got an incorrect answer, where did the process break down? Did you remember how two sets of data are related, or that an infant’s development in the womb can influence its mortality and survivability? Did you have trouble breaking down the graph to determine the correct answer?
20) E 21) C 22) A 23) A
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Clarify Question ● What is the key concept addressed by the question?● This question is asking you to predict what will happen to allele frequencies if female cardinals select male mates based upon their red color. ● What type of thinking is required?● You are being asked to take what you already know and use, or apply, it to the concept of sexual selection to the Hardy-Weinberg principle. ● What key words does the question contain and what do they mean?● Hardy-Weinberg equilibrium, which refers to populations whose genotype frequencies do not change from generation to generation. ● Frequency, which refers to the number of times a particular event occurs in a sample. ● Allele, which refers to a version of a gene. Gather Content ● What do you already know about the Hardy-Weinberg principle? How does it relate to the question?● The Hardy-Weinberg principle states that the original proportions of the genotypes in a population will remain constant from generation to generation, as long as the following assumptions are met:1.No mutation takes place. 2.No genes are transferred to or from other sources. 3.Mating is random. 4.The population size is very large. 5.No selection occurs. ● The question stem violates one of the five assumptions. Which assumption is violated and how will this influence changes in the allele frequency? Consider Possibilities Version 1
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● What other information is related to the question? Which information is most useful?● The question states that female cardinals will select male mates based upon a characteristic they possess. If a male does not possess that characteristic, then they will not be able to find a female to mate with and thus their fitness will decrease. What would happen to the frequency of alleles that do not code for bright red color? Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● To answer this question, you may choose to identify the Hardy-Weinberg condition that is not being met and then identify how that condition may influence allele frequency in a population. In this specific example, female cardinals prefer to mate with bright red males. How will this influence the frequency of the allele that codes for the bright red color? Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to determine the effect selection would have on a population. ● Answering this question correctly depended on your ability to use the Hardy-Weinberg principle in a new situation. ● If you got the correct answer, excellent! If you got an incorrect answer, where did the process break down? Did you remember the five assumptions for Hardy-Weinberg equilibrium, or that selection for a certain phenotype can influence an allele’s frequency? Did you have trouble understanding how a phenotype is tied to a set of alleles? 24) D Version 1
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25) C 26) A 27) C 28) A 29) D 30) C 31) D 32) B 33) C 34) D 35) E 36) B 37) A
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Clarify Question ● What is the key concept addressed by the question?● This question is asking you to analyze how two different populations of birds will evolve based on where the populations live throughout the year. ● What type of thinking is required?● This is an analyze question because you have to determine the effect of migratory birds on HardyWeinberg equilibrium. ● What key words does the question contain and what do they mean?● Hardy-Weinberg equilibrium, which refers to populations whose genotype frequencies do not change from generation to generation. ● Migration, which means that individuals move from one location to another ● Population, which refers to a group of individuals living in the same area that can interbreed and produce fertile offspring. Gather Content ● What do you already know about the Hardy-Weinberg principle? How does it relate to the question?● The Hardy-Weinberg principle states that the original proportions of the genotypes in a population will remain constant from generation to generation, as long as the following assumptions are met:1.No mutation takes place. 2.No genes are transferred to or from other sources. 3.Mating is random. 4.The population size is very large. 5.No selection occurs. Consider Possibilities ● What other information is related to the question? Which information is most useful?● The question states that an island Version 1
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populated by ground-dwelling birds is on the migration route of sea birds. In regards to the assumptions for Hardy-Weinberg equilibrium, these two populations are different in one key assumption. One of the populations in the question stem violates one of the five assumptions. Which population violates which assumption? Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● To answer this question, you may choose to identify the Hardy-Weinberg condition that is not being met and then identify which population is not meeting that condition. In this specific example, an island populated by grounddwelling birds is on the migration route of sea birds. Information in the question stem provides clues to which Hardy-Weinberg condition is not being met. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to determine the impact of migratory birds vs. nonmigratory birds on Hardy-Weinberg equilibrium in both populations. ● Answering this question correctly depended not only on distinguishing between migratory sea birds and ground-dwelling birds, but on your ability to break down, or analyze, how the Hardy-Weinberg principle is applied to this particular situation. ● If you got the correct answer, excellent! If you got an incorrect answer, where did the process break down? Did you remember the five assumptions for Hardy-Weinberg equilibrium, or that statements within the question stem could provide clues for identifying the conditions for Hardy-Weinberg equilibrium? Did you have trouble breaking down how Version 1
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the Hardy-Weinberg principle could be applied to this situation to determine the correct answer? 38) C 39) A 40) D 41) D 42) A 43) C
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Clarify Question ● What is the key concept addressed by the question?● This question is asking you to calculate various frequencies for a population in HardyWeinberg equilibrium. What are the formulas involved in calculating the frequencies for a population in Hardy-Weinberg equilibrium? ● What type of thinking is required?● This is an analyze question because you have to calculate various frequencies for a population in Hardy-Weinberg equilibrium. ● What key words does the question contain and what do they mean?● Autosomal, which refers to genes located on the non-sex chromosomes. ● Frequency, which refers to the number of times a particular event occurs in a sample. ● Heterozygote, which means the individual contains different alleles for the gene. ● Carriers, which means the individual contains one deleterious allele and one normal allele for the gene. ● Dominant allele, which refers to a version of a gene expressed as a phenotype even if the allele was inherited from a single parent. ● Recessive allele, which refers to a version of a gene expressed as a phenotype only if the allele was inherited from both parents. ● Hardy-Weinberg equilibrium, which refers to populations whose genotype frequencies do not change from generation to generation. Gather Content ● What do you already know about the Hardy-Weinberg principle? How does it relate to the question?● To solve this problem you will need to apply the Hardy-Weinberg equations. Recall that there are two equations involved in the Hardy-Weinberg principle. One equation is p + q = 1; where p is the frequency of the dominant allele, q is the Version 1
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frequency of the recessive allele, and 1 is 100% of the alleles. The other equation is p2 + 2pq + q2 = 1; where p2 is the frequency of the homozygous dominant genotype, 2pq is the frequency of the heterozygous genotype, q2 is the frequency of the homozygous recessive genotype, and 1 is 100% of the individuals. How are these two equations related? How can we go from a homozygous genotype frequency to an allele frequency? Consider Possibilities ● What other information is related to the question? Which information is most useful?● The question provides you with two different numbers to calculate the frequency of an autosomal recessive trait. One of these numbers is the part of the population expressing the trait and the other number is total population. How can you calculate a frequency if you know the number expressing the trait of interest and the number for the whole population? Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● To answer this question you must determine which genotype frequency you are given. Keep in mind that you may have a dominant phenotype with either a homozygous dominant or heterozygous genotype. What genotype do you have if you express the recessive phenotype? ● How do you get from a value that is squared, like p2, to a value that is not squared but has the same variable, like p? What is the mathematical function involved in this process? Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result?● This question asked you to determine the frequency of heterozygotes. ● Answering this question correctly depended not only on distinguishing between genotypic and phenotypic frequencies, but on your ability to break down, or analyze, phenotypic frequencies. ● If you got the correct answer, excellent! If you got an incorrect answer, where did the process break down? Did you remember how to calculate the square root of a decimal? Do you understand that the recessive phenotype must have a homozygous recessive genotype? Therefore, the frequency of the recessive phenotype must equal the frequency of which genotype? Did you have trouble breaking down the Hardy-Weinberg equations to determine the correct answer? 44) E
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Clarify Question ● What is the key concept addressed by the question?● This question is asking you to calculate various frequencies for a population in HardyWeinberg equilibrium. What are the formulas involved in calculating the frequencies for a population in Hardy-Weinberg equilibrium? ● What type of thinking is required?● This is an analyze question because you have to calculate various frequencies for a population in Hardy-Weinberg equilibrium. ● What key words does the question contain and what do they mean?● Dominant phenotype, which refers to the physical trait of a version of a gene inherited from a single parent. ● Recessive allele, which refers to the physical trait of a version of a gene inherited from both parents. ● Hardy-Weinberg equilibrium, which refers to populations whose genotype frequencies do not change from generation to generation. ● Allele, which refers to a version of a gene. Gather Content ● What do you already know about the Hardy-Weinberg principle? How does it relate to the question?● To solve this problem you will need to apply the Hardy-Weinberg equations. Recall that there are two equations involved in the Hardy-Weinberg principle. One equation is p + q = 1; where p is the frequency of the dominant allele, q is the frequency of the recessive allele, and 1 is 100% of the alleles. The other equation is p2 + 2pq + q2 = 1; where p2 is the frequency of the homozygous dominant genotype, 2pq is the frequency of the heterozygous genotype, q2 is the frequency of the homozygous recessive genotype, and 1 is 100% of the individuals. How are these two equations related? How can we go from a phenotype frequency to an allele Version 1
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frequency? Which phenotype frequency is the same as one of the genotype frequencies? Consider Possibilities ● What other information is related to the question? Which information is most useful?● The question provides you with the frequency of the recessive phenotype. The recessive phenotype is equivalent to the homozygous recessive genotype. If you can calculate the frequency of the homozygous recessive genotype, then which allele frequency can you determine? Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● To answer this question you must determine which phenotype frequency matches a genotype frequency. Keep in mind that you may have a dominant phenotype with either a homozygous dominant or heterozygous genotype. What genotype do you have if you express the recessive phenotype? ● How do you get from a value that is squared, like p2, to a value that is not squared but has the same variable, like p? What is the mathematical function involved in this process? Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to determine the frequency of the dominant allele. ● Answering this question correctly depended not only on distinguishing between genotypic and phenotypic frequencies, but on your ability to break down, or analyze, phenotypic frequencies. Version 1
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● If you got the correct answer, excellent! If you got an incorrect answer, where did the process break down? Did you remember how to calculate the square root of a decimal? Do you understand that the recessive phenotype must have a homozygous recessive genotype? Therefore, the frequency of the recessive phenotype must equal the frequency of which genotype? Did you have trouble breaking down the Hardy-Weinberg equations to determine the correct answer? 45) D
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Clarify Question ● What is the key concept addressed by the question?● This question is asking you to calculate various frequencies for a population in HardyWeinberg equilibrium. What are the formulas involved in calculating the frequencies for a population in Hardy-Weinberg equilibrium? ● What type of thinking is required?● This is an analyze question because you have to calculate various frequencies for a population in Hardy-Weinberg equilibrium. ● What key words does the question contain and what do they mean?● Autosomal, which refers to genes located on the non-sex chromosomes. ● Frequency, which refers to the number of times a particular event occurs in a sample. ● Heterozygote, which means the individual contains different alleles for the gene. ● Carriers, which means the individual contains one deleterious allele and one normal allele for the gene. ● Dominant allele, which refers to a version of a gene expressed as a phenotype even if the allele was inherited from a single parent. ● Recessive allele, which refers to a version of a gene expressed as a phenotype only if the allele was inherited from both parents. ● Hardy-Weinberg equilibrium, which refers to populations whose genotype frequencies do not change from generation to generation. Gather Content ● What do you already know about the Hardy-Weinberg principle? How does it relate to the question?● To solve this problem you will need to apply the Hardy-Weinberg equations. Recall that there are two equations involved in the Hardy-Weinberg principle. One equation is p + q = 1; where p is the frequency of the dominant allele, q is the Version 1
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frequency of the recessive allele, and 1 is 100% of the alleles. The other equation is p2 + 2pq + q2 = 1; where p2 is the frequency of the homozygous dominant genotype, 2pq is the frequency of the heterozygous genotype, q2 is the frequency of the homozygous recessive genotype, and 1 is 100% of the individuals. How are these two equations related? How can we go from a homozygous genotype frequency to an allele frequency? Consider Possibilities ● What other information is related to the question? Which information is most useful?● The question provides you with two different numbers to calculate the frequency of an autosomal recessive trait. One of these numbers is the part of the population expressing the trait and the other number is total population. How can you calculate a frequency if you know the number expressing the trait of interest and the number for the whole population? Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● To answer this question you must determine which genotype frequency you are given. Keep in mind that you may have a dominant phenotype with either a homozygous dominant or heterozygous genotype. What genotype do you have if you express the recessive phenotype? ● How do you get from a value that is squared, like p2, to a value that is not squared but has the same variable, like p? What is the mathematical function involved in this process? Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result?● This question asked you to determine the frequency of the carriers, or heterozygous individuals. ● Answering this question correctly depended not only on distinguishing between genotypic and phenotypic frequencies, but on your ability to break down, or analyze, phenotypic frequencies. ● If you got the correct answer, excellent! If you got an incorrect answer, where did the process break down? Did you remember how to calculate the square root of a decimal? Do you understand that the recessive phenotype must have a homozygous recessive genotype? Therefore, the frequency of the recessive phenotype must equal the frequency of which genotype? Did you have trouble breaking down the Hardy-Weinberg equations to determine the correct answer? 46) E
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Clarify Question ● What is the key concept addressed by the question?● This question is asking you to calculate various frequencies for a population in HardyWeinberg equilibrium. What are the formulas involved in calculating the frequencies for a population in Hardy-Weinberg equilibrium? ● What type of thinking is required?● This is an analyze question because you have to calculate various frequencies for a population in Hardy-Weinberg equilibrium. ● What key words does the question contain and what do they mean?● Dominant phenotype, which refers to the physical trait of a version of a gene inherited from a single parent. ● Recessive allele, which refers to the physical trait of a version of a gene inherited from both parents. ● Hardy-Weinberg equilibrium, which refers to populations whose genotype frequencies do not change from generation to generation. ● Allele, which refers to a version of a gene. ● Frequency, which refers to the number of times a particular event occurs in a sample. Gather Content ● What do you already know about the Hardy-Weinberg principle? How does it relate to the question?● To solve this problem you will need to apply the Hardy-Weinberg equations. Recall that there are two equations involved in the Hardy-Weinberg principle. One equation is p + q = 1; where p is the frequency of the dominant allele, q is the frequency of the recessive allele, and 1 is 100% of the alleles. The other equation is p2 + 2pq + q2 = 1; where p2 is the frequency of the homozygous dominant genotype, 2pq is the frequency of the heterozygous genotype, q2 is the frequency of the homozygous recessive Version 1
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genotype, and 1 is 100% of the individuals. How are these two equations related? How can we go from a homozygous genotype frequency to an allele frequency? Consider Possibilities ● What other information is related to the question? Which information is most useful?● The question provides you with the frequency of white flowers (w). If you know the frequency of the recessive allele, then which phenotype frequency can you calculate? If you know that phenotypic frequency, then how do you calculate the other phenotypic frequency? Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● To answer this question you must determine which genotype frequency you can calculate. Keep in mind that you may have a dominant phenotype with either a homozygous dominant or heterozygous genotype. What genotype do you have if you express the recessive phenotype? Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to determine the frequency of the dominant phenotype. ● Answering this question correctly depended not only on distinguishing between genotypic and phenotypic frequencies, but on your ability to break down, or analyze, phenotypic frequencies. ● If you got the correct answer, excellent! If you got an incorrect answer, where did the process break down? Did you remember how to Version 1
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calculate the square root of a decimal? Do you understand that the recessive phenotype must have a homozygous recessive genotype? Therefore, the frequency of the recessive phenotype must equal the frequency of which genotype? Did you have trouble breaking down the Hardy-Weinberg equations to determine the correct answer? 47) C
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Clarify Question ● What is the key concept addressed by the question?● This question is asking you to calculate various frequencies for a population in HardyWeinberg equilibrium. What are the formulas involved in calculating the frequencies for a population in Hardy-Weinberg equilibrium? ● What type of thinking is required?● This is an analyze question because you have to calculate various frequencies for a population in Hardy-Weinberg equilibrium. ● What key words does the question contain and what do they mean?● Dominant phenotype, which refers to the physical trait of a version of a gene inherited from a single parent. ● Recessive allele, which refers to the physical trait of a version of a gene inherited from both parents. ● Hardy-Weinberg equilibrium, which refers to populations whose genotype frequencies do not change from generation to generation. ● Allele, which refers to a version of a gene. Gather Content ● What do you already know about the Hardy-Weinberg principle? How does it relate to the question?● To solve this problem you will need to apply the Hardy-Weinberg equations. Recall that there are two equations involved in the Hardy-Weinberg principle. One equation is p + q = 1; where p is the frequency of the dominant allele, q is the frequency of the recessive allele, and 1 is 100% of the alleles. The other equation is p2 + 2pq + q2 = 1; where p2 is the frequency of the homozygous dominant genotype, 2pq is the frequency of the heterozygous genotype, q2 is the frequency of the homozygous recessive genotype, and 1 is 100% of the individuals. How are these two equations related? How can we go from an allele frequency to a homozygous Version 1
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genotype frequency? Consider Possibilities ● What other information is related to the question? Which information is most useful?● The question provides you with the frequency of the recessive allele. If you know the frequency of the recessive allele, then how can you find the frequency of homozygous recessive genotype? What phenotype will be expressed by the homozygous recessive genotype? Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● To answer this question you must determine how to calculate the homozygous recessive genotype frequency when you are given the frequency of the recessive allele. Keep in mind that you may have a dominant phenotype with either a homozygous dominant or heterozygous genotype. What genotype do you have if you express the recessive phenotype? Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to determine the frequency of the recessive phenotype. ● Answering this question correctly depended not only on distinguishing between genotypic and phenotypic frequencies, but on your ability to break down, or analyze, phenotypic frequencies. ● If you got the correct answer, excellent! If you got an incorrect answer, where did the process break down? Did you remember how to calculate the square root of a decimal? Do you understand that the Version 1
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recessive phenotype must have a homozygous recessive genotype? Therefore, the frequency of the recessive phenotype must equal the frequency of which genotype? Did you have trouble breaking down the Hardy-Weinberg equations to determine the correct answer? 48) C
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Clarify Question ● What is the key concept addressed by the question?● This question is asking you to calculate various frequencies for a population in HardyWeinberg equilibrium. What are the formulas involved in calculating the frequencies for a population in Hardy-Weinberg equilibrium? ● What type of thinking is required?● This is an analyze question because you have to calculate various frequencies for a population in Hardy-Weinberg equilibrium. ● What key words does the question contain and what do they mean?● Autosomal, which refers to genes located on the non-sex chromosomes. ● Frequency, which refers to the number of times a particular event occurs in a sample. ● Heterozygote, which means the individual contains different alleles for the gene. ● Dominant allele, which refers to a version of a gene expressed as a phenotype even if the allele was inherited from a single parent. ● Recessive allele, which refers to a version of a gene expressed as a phenotype only if the allele was inherited from both parents. ● Hardy-Weinberg equilibrium, which refers to populations whose genotype frequencies do not change from generation to generation. Gather Content ● What do you already know about the Hardy-Weinberg principle? How does it relate to the question?● To solve this problem you will need to apply the Hardy-Weinberg equations. Recall that there are two equations involved in the Hardy-Weinberg principle. One equation is p + q = 1; where p is the frequency of the dominant allele, q is the frequency of the recessive allele, and 1 is 100% of the alleles. The other equation is p2 + 2pq + q2 = 1; where p2 is the frequency of the Version 1
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homozygous dominant genotype, 2pq is the frequency of the heterozygous genotype, q2 is the frequency of the homozygous recessive genotype, and 1 is 100% of the individuals. How are these two equations related? How can we go from a homozygous genotype frequency to an allele frequency? Consider Possibilities ● What other information is related to the question? Which information is most useful?● The question provides you with two different numbers to calculate the frequency of an autosomal recessive trait. One of these numbers is the part of the population expressing the trait and the other number is total population. How can you calculate a frequency if you know the number expressing a phenotypic trait and the number for the whole population? Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● To answer this question you must determine which phenotypic frequency you are given. Keep in mind that you may have a dominant phenotype with either a homozygous dominant or heterozygous genotype. What genotype do you have if you express the recessive phenotype? ● How do you get from a value that is squared, like p2, to a value that is not squared but has the same variable, like p? What is the mathematical function involved in this process? Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to determine the percentage of the geese that are Version 1
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heterozygous. ● Answering this question correctly depended on distinguishing between genotypic and phenotypic frequencies, and your ability to calculate the frequency of heterozygotes. ● If you got the correct answer, excellent! If you got an incorrect answer, where did the process break down? Did you remember how to calculate the square root of a decimal? Do you understand that the recessive phenotype must have a homozygous recessive genotype? Therefore, the frequency of the recessive phenotype must equal the frequency of which genotype? Did you have trouble breaking down the Hardy-Weinberg equations to determine the correct answer? 49) A
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Clarify Question ● What is the key concept addressed by the question?● This question is asking you to calculate various frequencies for a population in HardyWeinberg equilibrium. What are the formulas involved in calculating the frequencies for a population in Hardy-Weinberg equilibrium? ● What type of thinking is required?● This is an analyze question because you have to calculate various frequencies for a population in Hardy-Weinberg equilibrium. ● What key words does the question contain and what do they mean?● Dominant phenotype, which refers to the physical trait of a version of a gene inherited from a single parent. ● Recessive allele, which refers to the physical trait of a version of a gene inherited from both parents. ● Hardy-Weinberg equilibrium, which refers to populations whose genotype frequencies do not change from generation to generation. ● Allele, which refers to a version of a gene. ● Homozygous, which means that both alleles for a gene are the same. ● Heterozygous, which means that the alleles for a gene are different. Gather Content ● What do you already know about the Hardy-Weinberg principle? How does it relate to the question?● To solve this problem you will need to apply the Hardy-Weinberg equations. Recall that there are two equations involved in the Hardy-Weinberg principle. One equation is p + q = 1; where p is the frequency of the dominant allele, q is the frequency of the recessive allele, and 1 is 100% of the alleles. The other equation is p2 + 2pq + q2 = 1; where p2 is the frequency of the homozygous dominant genotype, 2pq is the frequency of the heterozygous genotype, q2 is the frequency of the homozygous recessive Version 1
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genotype, and 1 is 100% of the individuals. How are these two equations related? How can we go from a phenotype frequency to an allele frequency? Which phenotype frequency is the same as one of the genotype frequencies? Consider Possibilities ● What other information is related to the question? Which information is most useful?● The question provides you with the frequency of the dominant phenotype. The recessive phenotype is equivalent to the homozygous recessive genotype. If you can calculate the frequency of the homozygous recessive genotype, then which allele frequency can you determine? Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● To answer this question you must determine which phenotype frequency matches a genotype frequency. Keep in mind that you may have a dominant phenotype with either a homozygous dominant or heterozygous genotype. What genotype do you have if you express the recessive phenotype? ● How do you get from a value that is squared, like p2, to a value that is not squared but has the same variable, like p? What is the mathematical function involved in this process? Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to determine the frequency of the dominant allele in peppered moths. Version 1
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● Answering this question correctly depended not only on distinguishing between genotypic and phenotypic frequencies, but on your ability to break down, or analyze, various frequencies. ● If you got the correct answer, excellent! If you got an incorrect answer, where did the process break down? Did you remember how to calculate the square root of a decimal? Do you understand that the recessive phenotype must have a homozygous recessive genotype? Therefore, the frequency of the recessive phenotype must equal the frequency of which genotype? Did you have trouble breaking down the Hardy-Weinberg equations to determine the correct answer? 50) D
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Clarify Question ● What is the key concept addressed by the question?● This question is asking you to calculate various frequencies for a population in HardyWeinberg equilibrium. What are the formulas involved in calculating the frequencies for a population in Hardy-Weinberg equilibrium? ● What type of thinking is required?● This is an analyze question because you have to calculate various frequencies for a population in Hardy-Weinberg equilibrium. ● What key words does the question contain and what do they mean?● Frequency, which refers to the number of times a particular event occurs in a sample. ● Heterozygote, which means the individual contains different alleles for the gene. ● Hardy-Weinberg equilibrium, which refers to populations whose genotype frequencies do not change from generation to generation. ● Allele, which refers to a version of a gene. Gather Content ● What do you already know about the Hardy-Weinberg principle? How does it relate to the question?● To solve this problem you will need to apply the Hardy-Weinberg equations. Recall that there are two equations involved in the Hardy-Weinberg principle. One equation is p + q = 1; where p is the frequency of the dominant allele, q is the frequency of the recessive allele, and 1 is 100% of the alleles. The other equation is p2 + 2pq + q2 = 1; where p2 is the frequency of the homozygous dominant genotype, 2pq is the frequency of the heterozygous genotype, q2 is the frequency of the homozygous recessive genotype, and 1 is 100% of the individuals. How are these two equations related? How can we go from a homozygous genotype frequency to an Version 1
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allele frequency? Consider Possibilities ● What other information is related to the question? Which information is most useful?● The question provides you with an allele frequency. How can you find the other allele frequency and subsequently the heterozygous genotype frequency? Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The question provides you with two different numbers to calculate the frequency of a dominant phenotype. One of these numbers is the part of the population expressing the trait and the other number is total population. How can you calculate a frequency if you know the number expressing the trait of interest and the number for the whole population? ● How do you get from a value that is squared, like p2, to a value that is not squared but has the same variable, like p? What is the mathematical function involved in this process? Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to determine the frequency of the heterozygous MN blood type. ● Answering this question correctly depended not only on distinguishing between genotypic and phenotypic frequencies, but on your ability to break down, or analyze, various frequencies. ● If you got the correct answer, excellent! If you got an incorrect answer, where did the process break down? Did you remember how to Version 1
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calculate the square root of a decimal? Do you understand that the recessive phenotype must have a homozygous recessive genotype? Therefore, the frequency of the recessive phenotype must equal the frequency of which genotype? Did you have trouble breaking down the Hardy-Weinberg equations to determine the correct answer? 51) A 52) D 53) A 54) D 55) A 56) A 57) A 58) A 59) C 60) A 61) B 62) A 63) A 64) A
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Clarify question: ● What is the key concept addressed by the question?● This question relates to relative fitness, from the textbook section on quantifying natural selection. ● What type of thinking is required?● This is an analyze question, because you are asked to analyze a data table. Gather Content: ● What do you already know about relative fitness? What other information is related to the question?● Relative fitness is a way to compare the fitness of different phenotypes. The most fit phenotype, with the most offspring, is defined as having relative fitness of 1.0. The fitness of other phenotypes is based on their ratio of offspring compared to that one. Choose Answer: ● Given what you now know, what information is most likely to produce the correct answer?● The answer is "No, because plants with small and medium petals had higher relative fitness." Plants with medium petals had 25 seeds on average, and relative fitness of 1.0. Small petal plants had 20 seeds, and relative fitness of 0.8. Large petal plants, by contrast, had the fewest seeds, and the lowest relative fitness - 15 seeds and fitness of 0.6. Reflection on Process: ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This was an analyze question. You needed to extract the information from the data table and pick the correct choice. The information presented was Version 1
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about relative fitness. Remember that the most fit phenotype is always 1.0, and the others are based on their ratio of offspring compared to that one. 65) C 66) D Clarify question: ● What is the key concept addressed by the question?● It comes from the section of the textbook that discusses sexual selection. Does the huge ornate tail of the peacock provide some kind of advantage? The data on this graph addresses that question. Once you’ve understood the graph you need to pick between the choices ● What type of thinking is required?● This is an analyze question Gather Content: ● What do you already know about sexual selection? What other information is related to the question?● There is a positive relationship, more spots = more mates. When you look at the choices, the graph is best described by only one of the choices. There is no information about peacocks with fewer than 140 or more than 165 spots. They may or may not exist but the graph has nothing to say about that. Eye spots clearly have a relationship to mating, and it is a strong positive relationship. Choose Answer: ● Given what you now know, what information is most likely to produce the correct answer?● The answer is “The more eyespots that a peacock has in his tail, the more mates he attracts. ● That is the best choice to summarize the data presented. Reflection on Process: ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This was an analyze question. You needed to extract the information from the graph and pick the correct choice. The information presented was about sexual selection. Knowing about sexual selection makes the graph more understandable, but the key to answering this question lies in your ability to extract the information from the graph.
67) B
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Clarify question: ● What is the key concept addressed by the question?● Planning an experiment to determine if the spots are the only thing effecting sexual selection. ● What type of thinking is required?● This is an analyze question, the choices you are being given are follow-up experiments to see if the correlation between spots and mating hold true. Gather Content: ● What do you already know about sexual selection and planning an experiment? What other information is related to the question?● This question concerns sexual selection. In peafowl, more spots equals more mating but there could be a third factor involved. The goal of the next experiment is to test only the variable of spots and see if just a variation in spots alone produces a change in mating success. Is the number of spots the main factor when a peahen picks a peacock? In order to determine if the link were real, a researcher would need several peacocks that were similar in every way (same size, same age, same level of fitness) but they differed in spot number. An experiment like that would be able to provide evidence to show that the link between spots and mating success is real. Choose Answer: ● Given what you now know, what information is most likely to produce the correct answer?● The experimental design that involves adding and removing spots is the best choice. Reflection: ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result?● Did you get the correct answer? The key to this question is to understand the difference between correlation and causation. 68) A
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Clarify question: ● What is the key concept addressed by the question?● What is the origin of a feature in swordtail fish that is involved in sexual selection in a related species. ● What type of thinking is required?● This is an analyze question. You are given 4 different explanations for the observation of female preference for long tails in species of fish where the males do not normally have long tail fins. Gather Content: ● What do you already know about the evolutionary origins of a characteristic involved in sexual selection? What other information is related to the question? ● Male swordtails have long tail fins that they use to attract females. Closely related fish species (platys) also preferentially mate with males with long tail fins, but the long tail fins aren’t found in the platy males. This was discovered by attaching artificial swordtails to platy males. The question is asking you to pick be best explanation for the observation in female platys. If the genes for the production of swordtails and the neural mechanism for preference were the same genes, then in all species where females show a preference for swordtails, the male would have swordtails. Choose Answer: ● Given what you now know, what information is most likely to produce the correct answer?● The genes for preference may have evolved first in an ancestral species, followed by the development of swordtails in only one of the species that evolved. Reflection on Process: ● Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Did you choose the correct answer? The key here is to recognize that the preference for a particular male trait precedes the development of that trait. 69) D
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Clarify question: ● What is the key concept addressed by the question?● The question is about mate choice in Mormon crickets, but to answer the question you need to interpret the data in a graph. ● What type of thinking is required?● This is an analyze question. You need to use the data in the graph to pick the best choice.
Gather Content: ● What do you already know about mate choice? What other information is related to the question?● This question is from the section of the textbook that discusses mate choices and parental investment in offspring. Some animals provide lots of care to a small number of offspring; some animals provide no parental care. If an animal does not provide parental care then the most common strategy is to produce as many offspring as possible. Mormon crickets do not care for their young. Is there a relationship between female body weight and the number of eggs produced? Is the relationship positive or negative? Is an increase in body mass increase in the number of eggs? Choose Answer: ● Given what you now know, what information is most likely to produce the correct answer?● There are five choices presented, but the graph really only provides evidence for one of them. The only information that the graph provides is to show that larger females have more eggs. The other choices may or may not be true but the graph does not say anything about those choices. Reflection on Process: ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Did you get the question right? You needed to extract the information from the graph and pick the correct choice. The information presented was about the relationship between mass and number of eggs, but that wasn’t going to immediately point you to the correct answer. The key to answering this question lies in your ability to extract the information from the graph.
70) C
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Clarify question: ● What is the key concept addressed by the question?● Mate selection and parental investment involved in this species where the male and female roles are reversed. ● What type of thinking is required?● This is an analyze question, you will need to break down the choices into their components to find the correct answer. You are given choices for female breeding behaviors and are being asked to pick the best one. Gather Content: ● What do you already know about traditional roles of mate selection and parental investments? What other information is related to the question?● The key is to recognize the role of parental investment in raising offspring. Normally male animals provide less care, female choose the best quality male they can find and then do most of the parental care (if any parental care is being provided). The situation with these birds is reversed. Females still produce eggs and males still produce sperm, the behaviors are different but the sexes are the same. A single male could not possible maintain a large number of females if her is providing all of the parental care. If females are going to compete for males then the expectation is that the females will be the brightly colored sex (that is the case with these birds). Choose Answer: ● Given what you now know, what information is most likely to produce the correct answer?● The correct choice is that females compete and males choose the females. Reflection: ● Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Did you select the correct answer? Recognizing that the roles are reversed in this species is the key of finding the answer to this question. 71) D
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Clarify question: ● What is the key concept addressed by the question?● This question relates to genetic drift, from the textbook section on interactions among evolutionary forces. ● What type of thinking is required?● This is an analyze question, because you are asked to analyze the situation to describe the effect of drift. Gather Content: ● What do you already know about genetic drift? What other information is related to the question?● Genetic drift is typically weaker than natural selection, except when populations are small. Then it acts randomly, but tends to limit variation. It may drive one allele or another to fixation, without regard for which gives higher fitness. Choose Answer: ● Given what you now know, what information is most likely to produce the correct answer?● The answer is that genetic drift will "act randomly with respect to the trait." It may end up fixing the "good" allele or the "bad" one over time -- it's random. Reflection on Process: ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This was an analyze question. You needed to look at the situation and combine what you knew about selection and genetic drift to get the answer. Remember, that although genetic drift sometimes acts against selection, it's actually random with regard to fitness.
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72) E
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Clarify question: ● What is the key concept addressed by the question?● This question relates to gene flow and natural selection, from the textbook section on the interactions among evolutionary forces. ● What type of thinking is required?● This is an analyze question, because you are asked to analyze the situation and predict what species would show the least gene flow. Gather Content: ● What do you already know about gene flow? What other information is related to the question? ● Gene flow happens when individuals brings their genes into a population. Gene flow will tend to counteract the effects of natural selection because it brings in unselected DNA from outside. Choose Answer: ● Given what you now know, what information is most likely to produce the correct answer?● The researcher should choose an organism with low gene flow. The answer is "Slug." The other species are likely to have higher gene flow in to the site. Birds fly... pollen can travel on the wind. Humans drive cars. And deer are large animals that can travel widely. But slugs are small and slow, so they don't travel as widely. There is likely to be less gene flow in, and therefore the effects of selection will be more apparent. Reflection on Process: ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This was an analyze question. You needed to dissect the information to Version 1
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choose the best species. Remember that when two evolutionary forces interact, the outcome depends on which is stronger in the situation. Gene flow is stronger when a species travels more. 73) E
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Clarify question: ● What is the key concept addressed by the question?● This question relates to sexual selection, from the textbook section on reproductive strategies. ● What type of thinking is required?● This is an apply question, because you are asked to apply what you learned about sexual selection to a new example. Gather Content: ● What do you already know about sexual selection? What other information is related to the question? ● Sexual selection can be between the same sex -- like male vs. male fighting, which would be intrasexual selection. Or it can be between opposite sexes -- intersexual selection. Choose Answer: ● Given what you now know, what information is most likely to produce the correct answer?● The answer is "intersexual selection." The females are selecting the male elk, so it is between sex selection, or intersexual selection. Reflection on Process: ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This was an apply question. You needed to apply what you learned about sexual selection and relate it to the Irish Elk example. Remember that "intra" means within, and "inter" means between.
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Chapter 21 13e CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 1) Which observation(s) of the medium ground finch (Geospiza fortis) by Peter and Rosemary Grant verify Darwin's selection hypothesis? Check all that apply. A) Considerable variation existed in the beak size and shape of this finch. B) The medium ground finch showed assortative mating according to beak size and shape. C) Beak shape (depth) varied with the dryness of the year. D) Offspring were similar to parents in beak size and shape.
2) Which aspects of natural selection are illustrated by the figure below? Check all that apply.
A) Variation must exist in the population. B) Variation among individuals must be genetically transmissible to the next generation. C) Variation among individuals leads to differences in lifetime reproductive success. D) More individuals are produced each generation than the environment can support, resulting in competition for survival.
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3)
Indicate which factors support the industrial melanism hypothesis. Check all that apply. A) Pollution inhibits the growth of dark colored lichen. B) Dark moths have greater camouflage on trees in polluted woodlands. C) Pollutants darken bark surfaces. D) Light moths have greater camouflage on trees in highly polluted woodlands.
4) Choose the true statement(s) about the evolutionary divergence of horses in North America. Check all that apply. A) Most changes are seen as adaptations for life in grassland habitats. B) The general trends during horse evolution are increase in body size, reduction of digits, and tooth development for a grazing lifestyle. C) Horse evolution is unusual in that rates of change were uniform and constant throughout most lineages. D) Living lineages of horses show much less diversity than existed in the past.
5) Which of the following features of ancient horses are adaptations for living on open grasslands? Check all that apply. A) multiple toes that increased flexibility B) complex patterns of ridges on molar and premolars that increased chewing ability C) lengthening of limbs that increased running speed over long distances D) decrease in body size that increased agility in confined spaces
6) A new winged species is discovered in the Amazon rainforest. What evidence would support homology to vertebrate wings, rather than insect wings? Check all that apply.
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A) The wings have an underlying bone structure. B) The wings are poisonous. C) Blood vessels are networked through the wings. D) The wings are covered in chitinous scales.
7) Which observations illustrate shared ancestry by anatomical comparison studies? Check all that apply. A) The same structure has evolved to carry out different functions. B) Different structures evolve in similar ways when subjected to the same selective pressures. C) A structure becomes vestigial. D) Structures are found to be homologous.
8)
Choose the scientific evidence that supports evolutionary theory. Check all that apply. A) the fossil record B) homologous structures C) the molecular record D) intelligent design E) vestigial structures
9) Select all of the following that are valid counterarguments to the idea that evolution is "just a theory." A) Scientists use the word theory to describe unifying ideas. B) Evolution is just a collection of facts without a central theme and this is not a theory. C) Scientific theories are supported by many types of evidence and no empirical data refutes them. D) Evolution occurred in the past, but it is not occurring in the present, so it cannot be a theory.
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10) What evidence would support the hypothesis that snakes evolved from earlier reptiles with legs? Check all that apply. A) Snakes have skulls and jawbones. B) Some snake-like fossils have legs. C) Modern boa constrictors have vestigial hip bones. D) Snake embryos temporarily develop limb buds which are reabsorbed before birth. E) Many invertebrate species also lack legs.
11) Select the pairs of organism characteristics that are homologous structures. Check all that apply. A) oak leaves; maple leaves B) human hand bones; whale fin bones C) bat wing; butterfly wing D) octopus eye; mouse eye
12) Select the statements that provide biogeographical evidence for evolutionary theory. Check all that apply. A) Unrelated organisms in similar habitats often exhibit similar characteristics. B) Terrestrial mammals are not found naturally on any island greater than 300 miles from a mainland. C) Organisms on islands are most related to ones on the nearby mainland, even when the habitats are quite different. D) Invasive rats have colonized more than 80% of the world's islands.
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 13) Which statement describes artificial selection, but not natural selection?
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A) Most organisms are capable of producing more offspring than typically survive. B) Phenotypic variation is mostly selected by humans. C) Phenotypic variation exists within populations. D) Phenotypic variation can influence reproductive success. E) Phenotypic variation is at least partly due to inherited characteristics.
14) A certain plant species has small, thin seeds, and can grow and produce seeds in either wet years or dry years. Imagine that this plant species became invasive in the Galapagos and outcompeted most of the native plants. How would you expect this change to affect the evolution of beak size in the medium ground finch population? A) Small beaks would be favored under all rainfall conditions. B) Small beaks would be favored in wet years and large beaks would be favored in dry years. C) Large beaks would be favored in wet years and small beaks would be favored in dry years. D) Large beaks would be favored under all rainfall conditions.
15) In studying the medium ground finch on Daphne Major, the Grants noted that each generation of finches had beaks A) best suited for their parents' environment. B) best suited for their current environment. C) smaller than those of the previous generation. D) larger than those of the previous generation.
16)
Industrial melanism refers to
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A) high rates of melanoma due to pollution. B) darker-colored individuals dying off due to selection in a polluted environment. C) darker-colored individuals predominating due to selection in a polluted environment. D) increased mutation rates due to pollution. E) increased extinction rates due to habitat loss and a polluted environment.
17) The evidence for industrial melanism being caused by an increase in the dark allele was provided from field tests carried out by A) Kettlewell. B) Lamarck. C) Darwin. D) Tutt. E) Wallace.
18) The shape of the beaks of Darwin's finches and industrial melanism are often cited as examples of the process of_________blank leading to evolutionary change. A) artificial selection B) coevolution C) intelligent design D) founder effect E) natural selection
19) Natural selection has favored the dark form of the peppered moth in areas subject to severe air pollution, perhaps because on darkened trees, moth-eating birds see them less easily. As pollution abated, the light forms increased in the population because A) light moths had lower fitness than dark moths. B) light moths survived and produced more offspring than dark moths. C) light moths were more genetically variable than dark moths. D) birds ate more light moths.
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20) Industrial melanism involving the peppered moth is an example of natural selection that has been observed in the last hundred years. Peppered moth have two distinct forms, with dark or light colored wings. Which of the following statements about these moths is true? A) The dark forms are selected against in nonpolluted forests. B) The dark forms are distasteful to birds and are thus safe in polluted forests. C) The light forms are selected against in nonpolluted forests. D) Birds prey more on the dark forms in polluted forests. E) Dark forms emigrate from nonpolluted forests to polluted forests.
21) In a hypothetical study, equal numbers of dark and light moths are marked and released in polluted and unpolluted woodlands. Then some are recaptured 10 days later. According to the industrial melanism hypothesis, what result would you predict? A) More dark moths should be recaptured in unpolluted woodlands than in polluted woodlands. B) More light moths should be recaptured in polluted woodlands than in unpolluted woodlands. C) More dark moths should be recaptured in polluted woodlands than in unpolluted woodlands. D) More of both types of moths should be recaptured in unpolluted woodlands than in polluted woodlands.
22)
Which "alternate" hypothesis might also explain industrial melanism?
A) Dark moths are more resistant to the toxic effects of pollution than light moths. B) Dark moths emigrate out of polluted areas to escape the pollution. C) Pollution kills important tree species that peppered moths depend on for egg laying. D) Because dark moths absorb more heat, they are more active and better able to avoid bird predation. E) Birds used the marks that Kettlewell placed on the moths when he released them to help them find and capture the moths.
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23)
Domestication of dogs has led to A) a variety of homologous structures. B) a variety of phenotypes. C) a variety of mutations. D) a variety of reproductively isolated breeds. E) a variety of different species.
24) The figure below shows results of bristle number in Drosophila flies after 35 generations of artificial selection. This figure suggests that
A) bristle number has been selected beyond the original range of phenotypic variation for this trait. B) after 35 generations of selection, populations no longer exhibit variation in bristle number. C) natural selection cannot lead to large phenotypic changes. D) at the end of the experiment, "high population" flies were unable to interbreed with "low population" flies.
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25) Comparing the evolution of domesticated dogs to the evolution of wolves illustrates what relationship between artificial and natural selection? A) Artificial selection is slower than natural selection. B) Artificial selection is reversible; natural selection is not. C) Artificial selection is more likely to produce maladaptive structures than natural selection. D) Artificial selection cannot produce changes as large as changes produced by natural selection. E) In artificial selection, the magnitude of the selection pressure can be varied; in natural selection, it cannot.
26) Considerably more phenotypic variation exists in domesticated varieties of species like dogs and cabbages than exists in non-domesticated species like lions and oak trees. What best explains why this is true? A) There is no selection and mating is random under domestication. B) During domestication, very high rates of mutation are induced. C) Genetic drift is important because domestication involves small populations. D) Many domesticated varieties would not survive in the natural world. E) Domesticated species exhibit "hybrid vigor" (heterosis).
27) Some of the most dramatic evidence for evolution has come from human agriculture. One of the most artificially selected crop plants is_________blank, which is very different than the parent teosinte plant. A) pea B) tomato C) potato D) corn E) asparagus
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28) A technique used in dating a rock can be used to accurately predict the age of the fossils occurring in the rocks. This technique involves A) fossil dating. B) successive rock layering. C) radioactive isotope decay. D) structural geology. E) developmental geology.
29)
Today, the fossil record
A) can be dated only in terms of how layers relate to each other (i.e. older layers are below younger layers); no actual dates can be estimated. B) can be dated reasonably well only with uranium-238. C) can be dated reasonably well using a variety of radioactive isotopes with known halflives. D) can be dated precisely, to within a single year, using radioactive isotopes. E) can be dated precisely, to within a single year, using DNA hybridization.
30)
Progressive changes in the fossil record are evidence for evolution because A) they show descent with modification. B) they show inheritance of acquired characteristics. C) they show evolutionary change at the level of the individual. D) they show gaps in the fossil record.
31)
The most likely explanation for why toothed whales have a blowhole is A) they evolved from an animal with gills. B) they evolved from an animal with nostrils. C) blowholes are better for large animals. D) blowholes are better for breathing underwater than gills are.
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32) Radioactive isotopes are used in dating materials from the distant past. Which of the following statements about radioactive dating techniques is true? A) It gives only the general ages of rock strata. (±100 million years). B) It gives exact ages of rock strata. (± 1 year). C) The younger the rock, the more radioactive decay. D) The older the rock, the more radioactive decay. E) It no longer works due to contamination from radioactive waste.
33) A rock contains 18 mg of the radioactive isotope carbon-14. The half-life of carbon-14 is 5,600 years. How many half-lives and years will it take before the carbon-14 decays to less than 4 mg? A) 1 half-lives; 5,600 years B) 2 half-lives; 11,200 years C) 3 half-lives; 16,800 years D) 4 half-lives; 22,400 years E) 9 half-lives; 50,400 years
34) The half-life of carbon-14 is 5,600 years. A fossil that has one-eighth the normal proportion of carbon-14 to carbon-12 is probably A) 2,800 years old. B) 5,600 years old. C) 11,200 years old. D) 16,800 years old. E) 22,400 years old.
35)
Which feature is visible on the Archaeopteryx fossil and shared with modern birds?
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A) homeothermy B) teeth C) feathers D) bony tail E) claws on forelimbs
36) In 2006, scientists discovered a fossil that had scales and gills, a flat head with eyes on top like a crocodile, and fin and neck bones that would allow it to prop itself out of the water. The best explanation for this fossil is that it is A) a transitional fossil between fish and amphibians. B) a transitional fossil between amphibians and reptiles. C) a ray-finned fish. D) a modern amphibian.
37)
Structures that have no apparent function but had a function in ancestral species are A) the fossil record. B) the molecular record. C) homology. D) development. E) vestigial structures.
38)
Homologous structures A) evolved independently despite looking the same. B) look different, but evolved from the same body part in a common ancestor. C) have the same appearance and function but do not derive from a common ancestor. D) have different appearance and function, and originated from different ancestors.
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39) The side toes of a horse, the pelvis of the whale, and the human appendix are all examples that played more important roles in an ancestor than the descendent, known as A) analogous structures. B) homologous structures. C) vestigial structures. D) homeotic mutations. E) acquired structures.
40) All vertebrates contain a similar pattern of organs, indicating that they are related to one another. This represents which of the following lines of evolutionary evidence? A) fossil record B) homology C) convergent evolution D) biogeography E) development
41) During development, human embryos have pharyngeal pouches (or "gill slits") that later develop into various glands. Fish embryos also have pharyngeal pouches, but these develop into gills. The best explanation for why both human and fish embryos have pharyngeal pouches is A) humans and fish share a common ancestor that had gills. B) human embryos need gill slits to breathe in the uterus. C) humans and fish both develop pharyngeal pouches by random chance. D) fish evolved from humans.
42) The evolution of similar forms in different lineages when exposed to the same selective pressures is called
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A) divergence. B) convergence. C) successive homology. D) descent. E) natural selection.
43) The observation that different geographical areas sometimes exhibit plant and animal communities of similar appearance, even though the individual plants and animals are not closely related, is called A) the fossil record. B) homology. C) convergent evolution. D) divergent evolution. E) adaptation.
44)
The pair of traits that best illustrates convergent evolution is A) an elephant's tusks and a beaver's teeth. B) a lizard's arm and a bird's wing. C) a dragonfly's wing and a butterfly's wing. D) a cartilage skeleton in a shark and a bone skeleton in a dolphin.
45) The marsupials in Australia closely resemble the placental animals of the rest of the world. This is an example of A) the fossil record. B) homology. C) convergent evolution. D) biogeography. E) development.
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46)
The streamlined bodies seen in sharks, tuna, and dolphins are due to A) a recent shared common ancestor. B) dissimilar selection pressures. C) selection for fast swimming. D) predation by the same predator. E) intelligent design.
47)
Evolution does not violate the second law of thermodynamics because A) evolution is a random process; it does not require an input of energy. B) Earth is not a closed system; it constantly receives an input of energy from the sun. C) living organisms are not subject to the second law. D) the disorder generated by extinction balances the order created by evolution.
48) Plants in the desert-adapted families Cactacea (cactus) and Euphorbia (euphorbs) share many of the same physical characteristics, such as succulent stems that store water and CAM photosynthesis, but they do not share a recent common ancestor. This evidence suggests that these families are an example of A) convergent evolution. B) homologous structures. C) vestigial structures. D) divergent evolution.
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49) The figure below shows the relationship between beak depth in the medium ground finch in the Galapagos and survivorship during a particular year. Assuming that beak depth is heritable, what do you predict about beak depth in the next generation?
©McGraw-Hill Education A) Mean beak depth will decrease. B) Mean beak depth will increase. C) Mean beak depth will stay about the same. D) Mean beak depth in the next generation cannot be predicted using this data.
50) A scientist studying peppered moths in Michigan observed that the percentage of melanic moths increased by around 2% from 1960-1961. Has evolution occurred in this population? A) No, because melanism wasn't adaptive at that time. B) No, because the frequency of the melanic moths did not change enough to be considered evolution. C) Yes, because the frequency of the melanic moths in the population changed over time. D) Yes, because the frequency of melanic moths decreased.
51) Complete this sentence to make it correct: Bird wings and bat wings are homologous...
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A) toArchaeopteryx wings. B) to each other. C) to each other and to insect wings too. D) as vertebrate forelimbs, but not as wings.
SECTION BREAK. Answer all the part questions.
52) <p> ©McGraw-Hill Education
52.1) The pattern of wet years and dry years shown will probably move the population toward A) all having larger beaks. B) all having smaller beaks. C) having intermediate size beaks. D) having two, distinct populations. E) maintaining variation in beak depth.
52.2) Which statement best describes the correlation between beak depths and the dryness of the environment?
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A) Birds with large beaks are favored during wet years. B) Birds with small beaks are favored in dry years. C) Birds with large beaks are favored during dry years. D) Birds with either size beak (large or small) are favored equally.
53) In the laboratory, fruit flies ( Drosophila) were artificially selected for the number of bristles on their bodies. One population (R) was selected for low numbers of bristles, a second population (S) for high numbers of bristles.
53.1)
In order for scientists to artificially select Drosophila for their number of bristles,
A) they had to induce mutations into their populations of Drosophila. B) they had to study the population for millions of years. C) genetic variation had to be present in the population. D) dramatic mutations had to be produced by the selection. E) the number of bristles in each Drosophila had to be random.
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53.2) After 35 generations of selection (about 1 year's time), the two populations were studied. Researchers found A) no change; it was much too soon. B) a slight increase of bristle numbers was already evident. C) a large overlap in the range of bristle numbers. D) bristle number could be decreased, but not increased. E) an increase in bristle number of one group and a decrease in the other, with no overlap.
54) Marsupials are a very ancestral form of mammal, evolving before placental mammals over 70 million years ago. Today Australian marsupials can be compared to placental mammals on other continents.
54.1)
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A) the marsupials have changed very little during the last 70 million years. B) different marsupials are similar to placental mammals in their adaptations to different niches. C) the marsupials became more adapted and diverse than the placental mammals. D) the marsupials all look alike, and the placentals all look alike. E) living marsupials are little changed from the first marsupial fossils.
54.2)
The similar pairs of marsupial and placental mammals are examples of
A) divergent evolution. B) monotonic evolution. C) heterozygote advantage. D) convergent evolution. E) homology.
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Answer Key Test name: Chap 21_13e_Raven 1) [A, C, D] 2) [A, B] 3) [B, C] 4) [A, B, D] 5) [B, C] 6) [A, C]
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Clarify Question What is the key concept addressed by the question? ● The question stem is asking you to select evidence supporting that the species’ wings are homologous to vertebrate wings, not insect wings. What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to comparing homologous structures. Gather Content What do you already know about homologous structures? What other information is related to the question? ● Homologous structures may have different appearances and functions even though they are derived from the same common ancestral body part. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Of the options available, which ones describe structures you would find within vertebrate limbs, such as wings? Bones and blood vessels are found in vertebrate animals. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use homologous structures in a new situation… If you got an incorrect answer, did you remember that homologous structures are derived from a common ancestor? Did you have trouble extending this evidence for evolution to determine the correct answer? 7) [A, C, D] 8) [A, B, C, E] Version 1
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9) [A, C] 10) [B, C, D]
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Clarify Question What is the key concept addressed by the question? ● The question stem is asking you to select which pieces of evidence would support the evolution of snakes from a reptile ancestor with legs. What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to the evolution of snakes. Gather Content What do you already know about the evidence for evolution? What other information is related to the question? ● Anatomical evidence for evolution can help determine the relatedness between divergent species. Embryonic development shows similarity in developmental patterns among species whose adult phenotypes are very different. Species that have lost a feature that was present in an ancestral form often develop and then lose that feature during embryological development. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● If snakes have no hind legs, then why would a hip bones be present in snakes? Why would embryonic snakes form limb buds? Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use the anatomical evidence for evolution in a new situation… If you got an incorrect answer, did you remember that the anatomical evidence for evolution includes vestigial structures and embryonic development? 11) [A, B] Version 1
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Clarify Question What is the key concept addressed by the question? ● The question stem is asking you to select examples of structures which are homologous. What type of thinking is required? ● This is an apply question because you have to use what you have learned and apply it to new examples. Gather Content What do you already know about homology? What other information is related to the question? ● Homology describes features of two animals that derive from a common ancestor who also had that feature, or a similar feature that may have changed. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Are octopus eyes and mouse eyes homologous? No, because their most recent common ancestor did not have complex eyes -- they evolved independently. ● Are bat wings and butterfly wings homologous? No, because their most recent common ancestor did not have wings -- they evolved independently. ● Are oak leaves and maple leaves homologous? Yes, because their most recent common ancestor had leaves. Oak leaves and maple leaves evolved from that common progenitor. ● Are human hand bones and whale fin bones homologous? Yes, because their most recent common ancestor had a forelimb with bones. The specialized human and whale bones evolved from that common progenitor. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on a clear understanding of homology, and your ability to think about each pair of examples. Did you remember the figure in the text that showed five examples of vertebrate forelimbs, with homologous bones? Did you remember the section of the book that described the differences between mollusk and vertebrate eyes? 12) [A, C] 13) B Artificial selection involves selective breeding by people to enhance desirable traits. 14) A
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Clarify Question What is the key concept addressed by the question? ● The question stem is asking you to determine how rainfall and the introduction of this new plant species will influence beak size selection. What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to natural selection of beak size. Gather Content What do you already know about natural selection? What other information is related to the question? ● Natural selection is a method by which organisms can evolve. The seeds from the new plant species will be common during times of drought or rainfall. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Recall that the Grants found birds with small beaks were favored in wet years because of the plentiful small, tender seeds and that birds with large beaks were favored in dry years because of the lack of small, tender seeds and the multitude of large, hard seeds. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use natural selection in a new situation… If you got an incorrect answer, did you remember that natural selection is influenced by biotic and abiotic factors, or that rainfall affects natural selection by influencing the type of seeds present in the environment? Did you have trouble extending natural selection to determine the correct answer? Version 1
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15) A Each generation of finches inherited beak size from the previous (parental) generation; it was the parental generation on which selection had acted to produce the offspring generation's distribution of beak size. 16) C Industrial melanism is a phenomenon in which the selective pressure changes due to environmental pollution; it results in a predominance of dark individuals over light individuals. 17) A Tutt first proposed the hypothesis that those moths more similar in color to the tree trunks on which they rested would be better camouflaged and thus survive longer and reproduce more. Kettlewell, however, set up experimental field tests to test the hypothesis. 18) E Natural selection occurred in both of these examples; the pressures leading to the selection of deeper beaks following drought or darker pigmentation following pollution were environmental changes. Natural selection is the change in allele frequencies from one generation to the next in response to changes in environmental pressures. 19) B While the darker phenotype was selected for after pollution killed the lichens and deposited soot on the tree trunks, after the Clean Air Act of 1956, pollutants were removed and light-colored lichens regrew, resulting in selection for the lighter phenotype. 20) A In nonpolluted forests, light-colored lichens cover the tree trunks, making the dark forms more susceptible to predation.
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21) C
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Clarify Question What is the key concept addressed by the question? ● The question stem is asking you to predict the results of a hypothetical study involving the release of marked dark and light colored moths into polluted and unpolluted woodlands. What type of thinking is required? ● This question is asking you to weight and judge, or evaluate, how natural selection will influence the moth color phenotypic frequencies. Gather Content What do you already know about natural selection? What other information is related to the question? ● Natural selection is a method by which organisms can evolve. Regardless of whether the moths are marked or unmarked, one phenotype will be favored in the polluted woods and the other phenotype will be favored in the unpolluted woods. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Note that within the polluted woods, the tree bark was darkened by soot from nearby factories. Moths with similarly colored wings would be harder to be seen by predators than moths with light colored wings. Therefore, moths with wings colored like their environment would better survive to be recaptured than the moths with wing color that contrasts with the environment. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to weigh and judge, or evaluate, natural selection and phenotypic frequencies. If Version 1
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you got an incorrect answer, did you remember that wing color confers a selective advantage if it matches the environment? Did you have trouble weighing the merits of wing color relative to the levels of pollution to determine the correct answer? 22) A
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Clarify Question What is the key concept addressed by the question? ● The question stem is asking you to identify which alternative hypothesis also explains why moths wing color frequencies changed as woodland pollution levels changed. What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to how natural selection will influence the moth color phenotypic frequencies. Gather Content What do you already know about natural selection? What other information is related to the question? ● Natural selection is a method by which organisms can evolve. A valid alternative hypothesis will provide a logical explanation for the observed phenomenon, industrial melanism. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● If dark moths emigrated, we would expect the preponderance of this morph to decrease, not increase. If the tree species was killed by pollution, then both moth morphs would be equally affected. There is no evidence that pollution increased heat, nor is there evidence that black moths absorb more heat and are subsequently more active. In any case, moths avoid predation by cryptic, hiding behavior, not by fleeing from their predators. Finally, Kettlewell placed the marks under the moths' wings and they were thus undetectable by the birds. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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● Answering this question correctly depended on your ability to use natural selection in a new situation… If you got an incorrect answer, did you remember that natural selection favors one morph over another, or that pollution affects morph frequency by selecting for the more cryptic morph? Did you have trouble extending natural selection to determine the correct answer? 23) B In dogs, artificial selection has led to a variety of different phenotypes; the different dog breeds are not considered separate species nor are they reproductively isolated. 24) A
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Clarify Question What is the key concept addressed by the question? ● The question stem is asking you to look at how artificial selection has caused the bristle number to change from the initial population to the low bristle number population and the high bristle number population. What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to the effects of artificial selection on variation within populations. Gather Content What do you already know about artificial selection? What other information is related to the question? ● Artificial selection occurs when humans select for a desired trait within a population. Humans have artificially selected for traits in dogs, resulting in different breeds of dogs. Can different breeds of dogs interbreed and produce mixed offspring? Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Artificial selection occurs when humans select for a desired trait within a population. Ultimately, the desired trait may become exaggerated within the population far beyond the levels of variation found within the initial population. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use artificial selection in a new situation… If you got an incorrect answer, did you remember that artificial selection is process commonly used by humans to select for desired traits, or that artificial selection affects variation by selecting specific characteristics? Did you have trouble extending your understanding of artificial selection to determine the correct answer?
25) C
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Clarify Question ● What is the key concept addressed by the question?● The question stem is asking you to compare a wild and a domesticated species. ● What type of thinking is required?● You are being asked to take what you already know and use, or apply, it to the question of fitness in domesticated species. Gather Content ● What do you already know about natural and artificial selection? What other information is related to the question?● Natural selection is a method by which organisms can evolve. The individuals with the highest fitness in the environment survive and reproduce, passing on their genes to the next generation. ● Artificial selection is when humans choose individuals for certain traits. They select which individuals can reproduce and pass on their genes. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● When humans selected dogs, different breeders were selected for different characteristics. Some chose big dogs, some small, etc. But many of the characteristics they selected did not increase fitness. In many cases, the traits selected in dog breeds dramatically lowered fitness. Many dog breeds would not survive in the wild. ● Humans wanted a variety of dog forms -- but this was only possible because humans were taking care of the dogs. Most domesticated animals would not survive well in the wild, because they have been selected away from the traits that worked best in nature.
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Answering this question correctly depended on your ability to consider artificial and natural selection and their implications. If you got an incorrect answer, did you remember that natural selection selects based on fitness, and artificial selection does not? In nature, varieties outcompete each other. Two very different forms are unlikely to have the same relative fitness. The form with the highest fitness tends to predominate over time. 26) D
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Clarify Question ● What is the key concept addressed by the question?● The question stem is asking you to explain why variation is often high in domesticated species. ● What type of thinking is required?● You are being asked to take what you already know and use, or apply, it to the question of variation in domesticated species. Gather Content ● What do you already know about natural and artificial selection? What other information is related to the question?● Natural selection is a method by which organisms can evolve. The individuals with the highest fitness in the environment survive and reproduce, passing on their genes to the next generation. ● Artificial selection is when humans choose individuals for certain traits. They select which individuals can reproduce and pass on their genes. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● When humans selected dogs, different breeders were selected for different characteristics. Some chose big dogs, some small, etc. ● When humans selected cabbages (Brassica sp.), different farmers also selected for different traits. Those differently-selected cabbages became bok choy, brussels sprouts, kale, kohlrabi, broccoli, and cauliflower. ● The humans wanted variety -- but the reason this was possible was that humans were taking care of the dogs, cabbages, etc. Most domesticated varieties of plants and animals would not survive well in the wild, because they have been selected away from the traits that Version 1
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worked best in nature. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Answering this question correctly depended on your ability to consider artificial and natural selection and their implications. If you got an incorrect answer, did you remember that natural selection selects based on fitness, and artificial selection does not? In nature, varieties outcompete each other. Two very different forms are unlikely to have the same relative fitness. 27) D 28) C 29) C 30) A 31) B
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Clarify Question ● What is the key concept addressed by the question?● The question stem is asking you to explain the origin of the whale's blowhole. ● What type of thinking is required?● This is an apply question because you have to use what you have learned about homology and whale evolution and apply it to this example. Gather Content ● What do you already know about homology and whales? What other information is related to the question?● Homology describes features of two animals that derive from a common ancestor who also had that feature or a similar feature. ● Whales are mammals, not fish. They evolved from a mammalian ancestor that had legs, then gradually became aquatic. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● Since whales evolved from mammals, not fish, they could not evolve gills. Selection could only act upon the variation in the features present in the ancestor -- nostrils. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Answering this question correctly depended on an understanding of homology, and your ability to think about whale evolution. Did you remember the figure in the book that showed the intermediate fossils from the evolution of whales?
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32) D 33) C
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Clarify Question What is the key concept addressed by the question? ● The question stem is asking you to calculate how many half-lives would occur in order to have less than 4 mg left of the original 18 mg of radioactive carbon-14. What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to the half-life of the radioactive isotope, carbon-14. Gather Content What do you already know about half-lives of radioactive isotopes? What other information is related to the question? ● Isotopes decay at a known rate, called their half-life. During each halflife, one-half of the original amount of parent isotope has transformed into a daughter isotope. Therefore, if a sample of material had 10 g of radioactive isotope and a half-life of 3 hours, then after three hours, or one half-life, the sample would have 5g of radioactive isotope and 5 g of the daughter isotope. After six hours, or two half-lives, the sample would have 2.5 g of radioactive isotopes and 7.5 g of the daughter isotope. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● The half-life of carbon-14 is 5,600 years. Therefore, after 5,600 years, the 18 mg sample of carbon-14 would have 9 mg of carbon-14 left. How many mg would be left after 11,200 years? What about after three halflives? What about after four or even nine half-lives? Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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● Answering this question correctly depended on your ability to use the concept of half-life in a new situation… If you got an incorrect answer, did you remember that half-life is the time it takes for one half of a sample of radioactive isotope to decay into the daughter isotope, or that the amount of time affects how many half-lives have occurred? Did you have trouble extending half-life to determine the correct answer? 34) D
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Clarify Question What is the key concept addressed by the question? ● The question stem is asking you to calculate how many half-lives would occur in order to have one-eighth of radioactive carbon-14 sample left. What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to the half-life of the radioactive isotope, carbon-14. Gather Content What do you already know about half-lives of radioactive isotopes? What other information is related to the question? ● Isotopes decay at a known rate, called their half-life. During each halflife, one-half of the original amount of parent isotope has transformed into a daughter isotope. Therefore, if a sample of material had 10 g of radioactive isotope and a half-life of 3 hours, then after three hours, or one half-life, the sample would have 5g of radioactive isotope and 5 g of the daughter isotope. After six hours, or two half-lives, the sample would have 2.5 g of radioactive isotopes and 7.5 g of the daughter isotope. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● The half-life of carbon-14 is 5,600 years. Therefore, after 5,600 years, the one half of your sample of carbon-14 would still be of carbon-14 left. What fraction of your sample would be left after 11,200 years? In order for 1/8 of a sample to remain 3 half-lives have passed. (1 divided by 2 equals 1/2, divided by 2 equals 1/4, divided by 2 equals 1/8) Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use the concept of half-life in a new situation… If you got an incorrect answer, did you remember that half-life is the time it takes for one half of a sample of radioactive isotope to decay into the daughter isotope, or that the amount of time affects how many half-lives have occurred? Did you have trouble extending half-life to determine the correct answer? 35) C 36) A 37) E 38) B 39) C 40) B Homologous structures are those shared among different species due to common ancestry. 41) A Many developmental features reflect the common ancestry of vertebrates. Many vertebrate embryos are nearly indistinguishable in the early stages to all but developmental biologists; the different species begin to differentiate as development progresses. 42) B 43) C 44) D
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Clarify Question What is the key concept addressed by the question? ● The question stem is asking you to select which pair of traits is an example of convergent evolution. What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to convergent evolution. Gather Content What do you already know about convergent evolution? What other information is related to the question? ● Convergent evolution explains how natural selection appears to favor parallel evolutionary adaptations in similar environments. Because selection in these instances has tended to favor changes that made the two groups more alike, their phenotypes have converged. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Convergent evolution occurs when traits are similar due to the natural selection of traits best adapted to similar environments. The traits are not similar due to a common ancestor between the two organisms. The skeletons of a shark (made from cartilage) and a dolphin (made from bone) are not a result of having a common ancestor. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use convergent evolution in a new situation… If you got an incorrect answer, did you remember that convergent evolution explains why two unrelated species may share similar phenotypic traits, or that the Version 1
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environment affects adaptations by the natural selection of the most adaptive phenotype? Did you have trouble extending convergent evolution to determine the correct answer? 45) C Environmental pressures provide the forces upon which natural selection acts. When organisms with some similar characteristics (size, diet, etc.) occupy similar niches in similar geographical areas, they may each evolve similar adaptations best suited for that environment. 46) C 47) B 48) A 49) C
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Clarify Question What is the key concept addressed by the question? ● The question stem is asking you to determine how the relationship between beak depth and relative fitness will influence future beak depth. What type of thinking is required? ● This is an analyze question because you have to break beak depth and relative fitness, or survivorship, into their component pieces to understand how they function in relation to one another. Gather Content What do you already know about fitness? What other information is related to the question? ● Fitness is a relative concept; the most fit phenotype is simply the one that produces, on average, the greatest number of offspring. ● Survivorship is connected to fitness because the birds must survive to reproduce. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Based on the graph, which phenotype presents the highest survivorship? How does survivorship influence an organism’s fitness relative to other organisms of different survivorship? If the survivorship for one phenotype is low, then how would the phenotypic variation be influenced? The mean beak size has the highest survivorship so it will be maintained. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended not only on distinguishing between beak depth and survivorship, but on your ability to break down, or analyze, how variation is influenced by beak depth and survivorship. If you got an incorrect answer, did you remember that relative fitness would likely affect variation by selecting for the phenotype best adapted to the environment? Did you have trouble breaking down how relative fitness influences variation levels to determine the correct answer?
50) C 51) D
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Clarify Question What is the key concept addressed by the question? ● The question stem is asking you to finish a sentence to correct a statement about homology. What type of thinking is required? ● This is an analyze question because you have to consider the details of bird and bat wings and their evolutionary history, to come to a conclusion. Gather Content What do you already know about homology? What other information is related to the question? ● Homology describes features of two animals that derive from a common ancestor who also had that feature, or a similar feature that may have changed. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Are bat wings and bird wings homologous as wings? No, because their most recent common ancestor did not have wings. And they are definitely not homologous to insect wings. Those three types of wings evolved independently and thus are not homologous. ● However, like the human arm, porpoise flipper, and horse leg, they are examples of the vertebrate forelimb. The most recent common ancestor of birds and bats did have a forelimb, and thus some aspects will be homologous -- just not as wings. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on a clear understanding Version 1
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of homology, and your ability to think about birds and bats and the evolutionary history of vertebrates. Did you remember the figure in the text that showed five examples of vertebrate forelimbs, with homologous bones? 52) Section Break 52.1) E
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Clarify Question What is the key concept addressed by the question? ● The question stem is asking you to assess how beak depth changes during the wet years and dry years. What type of thinking is required? ● This is an analyze question because you have to break beak depth and changes in precipitation into their component pieces to understand how they function in relation to one another. Gather Content What do you already know about natural selection? What other information is related to the question? ● Changes in the amount of precipitation influence the food available for consumption by the birds. Beak depth limits the birds to only certain food types. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Natural selection can only be applied to the variation found within the population. If the environment fluctuates between wet and dry years, then what kind of beak depth would be best adapted to the environment? It may seem like an intermediate beak size would also be favored in this example, however, the lack of food choices for that size of beak would be limited and therefore not favored. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended not only on distinguishing between precipitation and beak depth, but on your ability to break down, or analyze, how natural selection is Version 1
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influenced by the environment… If you got an incorrect answer, did you remember that components of natural selection include adaptations selected from the available variations within the population, or that environment would likely affect beak depth by changing which beak depth is best adapted to the changing environment? Did you have trouble breaking down how natural selection works to determine the correct answer? 52.2) C
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Clarify Question What is the key concept addressed by the question? ● The question stem is asking you to assess how beak depth changes during the wet years and dry years. What type of thinking is required? ● This is an analyze question because you have to break beak depth and changes in precipitation into their component pieces to understand how they function in relation to one another. Gather Content What do you already know about natural selection? What other information is related to the question? ● Changes in the amount of precipitation influence the food available for consumption by the birds. Beak depth limits the birds to only certain food types. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Natural selection can only be applied to the variation found within the population. If the environment fluctuates between wet and dry years, then what kind of beak depth would be best adapted to the environment? Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended not only on distinguishing between precipitation and beak depth, but on your ability to break down, or analyze, how natural selection is influenced by the environment… If you got an incorrect answer, did you remember that components of natural selection include Version 1
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adaptations selected from the available variations within the population, or that environment would likely affect beak depth by changing which beak depth is best adapted to the changing environment? Did you have trouble breaking down how natural selection works to determine the correct answer? 53) Section Break 53.1) C 53.2) E 54) Section Break 54.1) B 54.2) D
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Chapter 22 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) After an initial rapid rise in the number of species on Earth, there was a plateau that experienced very little fluctuation in the number of species. ⊚ ⊚
true false
CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 2) Scientists observed that marine bryozoan fossils lack intermediate forms. This evidence supports which hypotheses? Check all that apply. A) Evolution occurs in spurts, alternating with long periods of little change. B) Evolution proceeds steadily, with gradual, incremental change in a given evolutionary line. C) There is variability in the rate of evolution. D) Evolution proceeds at a constant rate that is the same for all organisms.
3)
Select all of the following that are postzygotic isolating mechanisms. A) Hybrids are sterile. B) Hybrids develop abnormally. C) Hybrids fail to become established in nature. D) Hybrids cannot be formed.
4)
Check all that apply: Members of the same biological species can A) have several isolated gene pools. B) differ from other species in one or more characteristics. C) generate fertile offspring with the members of a different species. D) interbreed freely with each other.
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5) Two hundred years ago, the fly species Rhagoletis pomonella only laid its eggs on fruit of the hawthorn tree. Today, different "host races" of R. pomonella lay their eggs on hawthorns OR apples. Apples occur within the range of hawthorns, so divergence between apple flies and hawthorn flies could be the first step in sympatric speciation. Choose the evidence that would suggest that R. pomonella is currently undergoing sympatric speciation. Check all that apply. A) Apple flies typically mate with apple flies, and hawthorn flies typically mate with hawthorn flies. B) Apple flies and hawthorn flies emerge from their hosts at different times of the year. C) Apple flies and hawthorn flies are able to form fertile hybrids. D) Apple flies and hawthorn flies are physically indistinguishable from each other.
6) Which examples would be considered different species under the biological species concept? Check all that apply. A) Two bear species are able to breed in zoos, but have separate ranges in nature. B) Two skunk species look morphologically similar, but are unable to interbreed. C) Two snake species look different, but often form fertile hybrids in nature. D) Two plant species have no gene flow between them. E) Two tree species have different leaf shapes, but form hybrids in their overlapping ranges.
7) Why do the Galápagos Islands and the Hawaiian Islands have so many endemic species of flies and birds? Check all that apply. A) There are numerous islands in each archipelago. B) There is adequate distance between islands to allow divergence. C) The founder effect was common when islands were colonized. D) Each bird or fly species has many common ancestors.
8) Choose the factors contributing to adaptive radiation of Drosophila in the Hawaiian Islands. Check all that apply.
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A) New islands were constantly being formed. B) There are high rates of mutation due to radioactive materials in the lava flows. C) The islands are highly volcanic, with lava flows breaking up the habitat. D) Drosophila species have no predators on the Hawaiian Islands.
9) Choose the true statements about the diversity of Darwin's finches on the Galápagos Islands. Check all that apply. A) All of the finch species share a common ancestor that colonized the islands. B) Prior to the adaptive radiation of finches, there were no unoccupied habitats in the Galápagos Islands. C) Competition among finches for food sources led to character displacement of beak shapes. D) Beak shape is not an important key innovation.
10)
Which statements about the Lake Victoria cichlid fishes are true? Check all that apply.
A) The adaptive radiation of the estimated 300 species of cichlid fish was very rapid and took place during the last 200,000 years. B) The adaptive radiation of the Lake Victoria cichlids may have resulted from a key evolutionary innovation. C) Speciation of the Lake Victoria cichlids was mainly allopatric. D) The diversity of the Lake Victoria cichlids continues today because the lake is devoid of predators. E) Many of the Lake Victoria cichlids have very specialized adaptations that allow them to occupy diverse habitats within the lake.
11) Which statements about gradualism and punctuated equilibrium are true? Check all that apply.
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A) Darwin's publication On the Origin of Species changed the view of evolution from gradualism to that of punctuated equilibrium. B) According to the theory of punctuated equilibrium, evolutionary change occurs only during brief periods of speciation. C) Stasis is likely caused by periods of disruptive and directional selection. D) Gradualism suggests that evolutionary change is not linked to speciation.
12) Two species regularly come into contact and form hybrids that have higher fitness than either of the parental species. What are some likely consequences of regular hybridization between these species? Check all that apply. A) evolution of a third species B) reinforcement of prezygotic isolating mechanisms C) extincton of one or both of the parental species. D) increased gene flow between the parental species E) complete reproductive isolation of the two original species
13) Indicate the scenario(s) that could directly result in sympatric speciation. Check all that apply. A) Two sunflower species cross to form a healthy hybrid individual with equal copies of chromosomes from each parental species. B) A new river channel divides a population of beetles into two populations. C) A large fence blocks the intermingling of two populations of a species. D) A subset of flies within a larger population colonizes a new host plant.
14) Select the reasons why adaptive radiations are often observed on remote volcanic islands. Check all that apply.
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A) When a new volcanic island forms, there are many empty niches. B) Only a few individuals reach remote islands. C) Remote islands have more plant diversity than the mainland does. D) Evolution is intrinsically faster on islands than on the mainland.
15)
Select the phrases that apply to the current mass extinction event. A) human-influenced B) asteroid C) Cretaceous period D) slow rebound of biodiversity
16)
Select the following statements that are related to mass extinctions.
A) A mass extinction occurs when extinctions sharply outpace the formation of new species. B) Periods of mass extinctions occurred five times on Earth before the modern era. C) The most severe mass extinction occurred at the end of the Cretaceous period. D) The current level of species diversity is so high it is highly unlikely that another mass extinction could occur. E) During periods of mass extinction, dominant groups of organisms are protected and survive to repopulate.
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 17) The model that assumes that evolution proceeds with slow successive change in a given evolutionary line is referred to as
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A) successive descent model. B) punctuated equilibrium. C) gradualism. D) the allopatric model. E) the sympatric model.
18) The type of speciation that results in the formation of separate species as a result of geographic isolation is called_________blank speciation. A) gradual B) sympatric C) allopatric D) sexual E) adaptive
19) When species are kept separate by preventing the formation of hybrid zygotes, the mechanism that keeps the species separate is known as a_________blank isolating mechanism. A) hybridization B) postzygotic C) prezygotic D) adaptive E) differential
20) A type of isolating mechanism that leads to reproductive isolation after a hybrid zygote has formed is called a_________blank isolating mechanism. A) hybridization B) postzygotic C) prezygotic D) adaptive E) differential
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21)
Which isolating mechanism is postzygotic? A) hybrid sterility B) behavioral isolation C) ecological isolation D) mechanical isolation E) temporal isolation
22)
Evolution acts at the level of the A) ecosystem. B) population. C) individual. D) community.
23) Hybridization regularly occurs between three species of Darwin’s finches on Daphne Major, but the finches are still considered different species because A) they have different fitnesses. B) they are reproductively isolated. C) they are mechanically isolated. D) they occupy different niches.
24) According to the biological species concept, two groups of organisms that are unable to form fertile, viable hybrids are considered to be different A) races. B) species. C) kingdoms. D) hybrids. E) cohabitants.
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25) In 1938, scientists found a population of coelacanths in the Indian Ocean. This fish species is considered a “living fossil” and appears not to have changed morphologically for 80 million years. This discovery supports the _________blank model of evolution. A) gradualism B) punctuated equilibrium C) adaptation D) natural selection E) common descent
26)
If populations within the same area split into species, the process is known as A) sympatric speciation. B) allopatric speciation. C) racial speciation. D) ecotypical speciation. E) reproductive speciation.
27) If two species are competing for the same resource, then either one species is likely to go extinct through competitive exclusion, or natural selection will drive the evolution of A) prezygotic isolating mechanisms. B) hybrids. C) character displacement. D) polyploid individuals.
28) Scientists found that different beak shapes correlate with different mating songs in Darwin's finches. Which hypothesis is most likely to explain this?
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A) Darwin's finches are not different species according to the Biological Species Concept. B) Adaptation to different food sources led to behavioral isolation in Darwin's finches. C) Mating songs are primarily determined by the acoustics of different beaks. D) Adaptation to different food sources likely occurred after reproductive isolation in Darwin's finches.
29)
Once species have formed, they keep their identity by A) developmental differences. B) genetic blocks. C) isolating mechanisms. D) somatic mutations. E) structural modifications.
30)
Many species might coexist in a particular environment by occupying different ecological A) biomes. B) niches. C) territories. D) domains. E) ranges.
31) Males of many marsupial species have forked penises that are incompatible with the anatomy of female placental mammals. What type of isolating mechanism does this represent? A) ecological isolation B) temporal isolation C) mechanical incompatibility D) hybrid sterility E) prevention of gamete fusion
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32) In the southeastern U.S., two species of wild lettuce ( Lactuca) do not usually form hybrids, because they bloom at different seasons. The means of isolation appears to be A) postzygotic and behavioral. B) prezygotic and temporal. C) prezygotic and geographical. D) prezygotic and mechanical. E) postzygotic and ecological.
33) The hundreds of species of Drosophila in Hawaii exhibit different mating rituals. This isolating mechanism is A) prezygotic and behavioral. B) prezygotic and temporal. C) prezygotic and geographical. D) postzygotic and mechanical. E) prezygotic and ecological.
34) Scientists studying a group of related bird species on an island archipelago discover that these species are always more closely related to each other within an island than they are between any two islands. The most likely explanation for this result is that A) each bird species evolved different adaptations in allopatry and then colonized the other islands. B) one bird species colonized each island and then evolved into distinct species on that island through character displacement. C) each bird species became reproductively isolated by living on a different island, then later colonized the other islands and acquired new adaptations. D) many ancestral bird species colonized each island.
35) Very rapid speciation occurred when cichlid fishes were isolated in Lake Victoria. More recently, widespread extinction occurred after
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A) artificial selection stopped. B) introduction of the Nile perch. C) hybridization stopped. D) fishing was prohibited. E) insect larvae were depleted.
36) Studies of snapping shrimp on either side of the Isthmus of Panama have shown that each Caribbean shrimp species is more closely related to a Pacific shrimp species than it is to any other Caribbean shrimp species. The most likely explanation for this result is A) snapping shrimp in the Caribbean and the Pacific were never part of the same population. B) snapping shrimp species in each ocean diverged prior to the formation of the Isthmus of Panama. C) snapping shrimp species in each ocean diverged after the formation of the Isthmus of Panama. D) creation of the Panama Canal allowed interbreeding between populations of shrimp.
37) The sunflower species Helianthus anomalus is thought to have been formed by hybridization between the sunflower species H. petiolaris and H. annuus because it contains a set of chromsomes from both parental species. H. anomalus is most likely an example of instantaneous speciation through A) allopolyploidy. B) autopolyploidy. C) parthenogenesis. D) hybrid sterility.
38) Punctuated equilibrium proposed by Eldredge and Gould in 1972 is an evolutionary process that involves
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A) gradual change observable in the fossil record with very little, if any, stasis. B) "spurts" of change observable in the fossil record followed by periods of stasis. C) gradual change observable in the fossil record followed by periods of stasis. D) "spurts" of change observable in the fossil record with very little if any stasis. E) gradual change observable in the fossil record followed by periods of no change at all.
39) A virgin pine forest covers a valley, and one of the inhabitants is a red squirrel species. A large volcanic eruption occurs and separates the valley with a huge lava flow, thus producing two populations of squirrels. What must occur for the two populations of squirrels to be considered separate species? A) The two squirrel populations must feed on different species of plants. B) The environment must change so that the populations exist in distinct habitats. C) The fur color or other morphological characteristic of the two squirrel populations must become distinct. D) The two squirrel populations must select mates using different behaviors. E) The two squirrel populations must be reproductively isolated.
40) Two bird species have different mating calls, occupy different habitats in nature, and when they hybridize, the hybrids are infertile. Which isolating mechanisms maintain these species? A) ecological isolation, behavioral isolation, and hybrid sterility B) mechanical isolation, hybrid sterility, geographical isolation C) ecological isolation, mechanical isolation, hybrid sterility D) geographical isolation, temporal isolation, behavioral isolation
41)
The most common mechanism for sympatric speciation in plants is
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A) polyploidy. B) geographic isolation. C) spontaneous mutation. D) punctuated equilibrium. E) disruptive selection.
42) Lake Victoria is famous for its variety of cichlid fishes. In fact, they offer the most diverse assembly of vertebrates presently known to science. One trait that scientists have focused on as one possible reason for their adaptability is A) a second set of scales that lie beneath the top outermost scales. B) a second set of jaws in their throats. C) gill arches that are not covered by an operculum, which prevents hiding places for gill parasites. D) digestive tracts that are able to process most substrates, which has eliminated the need for feeding specialization. E) ability to change color in relationship to their environment.
43) Two populations that inhabit the same area but remain genetically distinct can best be called A) genera. B) subspecies (races). C) polymorphic. D) allopatric species. E) sympatric species.
44)
The biological species concept of Ernst Mayr cannot be applied to
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A) sympatric organisms. B) allopatric organisms. C) eukaryotic organisms. D) plants and fungi. E) asexually-reproducing organisms.
45)
Which statement is true about speciation on island archipelagos? A) Speciation is slow because it depends on emigration from the mainland. B) Most speciation occurs allopatrically. C) Ecological competition may cause new species to go extinct slowing speciation. D) Speciation by polyploidy is most common. E) Species clusters are less common.
46)
Which form of speciation is most rapid? A) allopatric speciation on the mainland B) allopatric speciation on island archipelagos C) sympatric speciation via polyploidy D) sympatric speciation via disruptive selection E) sympatric speciation via character displacement
47) Several species of sea urchins may inhabit the same tide pool and their reproductive periods overlap. Although they practice external fertilization, they seldom interbreed because eggs produce chemicals that are only attractive to sperm of their own species. This is an example of a _________blank barrier that _________blank. A) prezygotic; causes geographic isolation B) prezygotic; causes temporal isolation C) prezygotic; prevents gamete fusion D) postzygotic; prevents zygote fusion E) postzygotic; causes hybrid infertility
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48) Many male songbirds have very distinctive songs that are used to attract females. These songs are an example of a _________blank isolating mechanism. A) postzygotic,ecological B) prezygotic,behavioral C) prezygotic,temporal D) postzygotic,mechanical E) prezygotic, gamete fusion
49) Due to character displacement, two closely related species may differ most morphologically when they A) are allopatric. B) are sympatric. C) occupy the same niche. D) occupy different niches. E) share a common ancestor.
50) Several new tetraploid species of a plant called salsify ( Tragopogon) appeared in western North America. These new species each arose from a diploid species that went through the process of allopolyploidy. This mode of speciation is a type of _________blank and it occurs _________blank. A) allopatric speciation; almost instantaneously B) allopatric speciation; very slowly C) sympatric speciation; almost instantaneously D) sympatric speciation; very slowly E) adaptive radiation; very slowly
51) Imagine two species of birds with similar beak sizes and diets. Where the two species are allopatric, we would expect that their beak sizes
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A) should be more different than when sympatric. B) should be more similar than when sympatric. C) should be larger than when sympatric. D) should be smaller than when sympatric.
52) If two species are able to mate and produce a hybrid offspring which can mate with other hybrid offspring, but is unable to mate with either parent's species, it is an example of A) allopatric speciation. B) sympatric speciation via disruptive selection. C) sympatric speciation via polyploidy. D) a species cluster. E) character displacement.
53) If a new species is produced by the interbreeding of two members of distinct species, this would be_________blank speciation achieved via_________blank. A) allopatric; autopolyploidy B) allopatric; allopolyploidy C) sympatric; autopolyploidy D) sympatric; allopolyploidy E) sympatric; divergence
54) Choose the best cause and effect sequence for the process of speciation by natural selection. A) Variation → Selection → Reproductive Isolation → Mutation → Speciation B) Mutation → Variation → Selection → Reproductive Isolation → Speciation C) Speciation → Reproductive Isolation → Selection → Mutation → Variation D) Variation → Reproductive Isolation → Speciation → Mutation → Selection E) Selection → Speciation → Reproductive Isolation → Variation → Mutation
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55)
Which is an example of temporal isolation?
A) one plant species blooms in June-July and a second plant species blooms in AugustSeptember. B) one plant species is pollinated by bees and a second plant species is pollinated by moths. C) two plant species live on the same mountainside, but one lives on rocky outcrops and the other in open meadows. D) two plant species have incompatible gametes.
56)
Reinforcement is most likely to drive the evolution of
A) prezygotic isolating mechanisms, because selection favors alleles that prevent hybridization. B) postzygotic isolating mechanisms, because selection acts after the formation of hybrids. C) prezygotic isolating mechanisms, because selection favors alleles that promote hybridization. D) postzygotic isolating mechanisms, because hybrids have low fitness relative to the parents.
57) NASA Scientists send a small population of dogs to a new planet in order to test if it will be hospitable for human colonization. Through a random lottery, only Great Dane and St. Bernard dog breeds are sent, and the resulting population consists of tall, longhaired dogs. After 100 years these dogs return to Earth and are no longer able to mate with Earth dogs. This scenario is an example of A) allopatric speciation through genetic drift. B) allopatric speciation through natural selection. C) sympatric speciation through genetic drift. D) sympatric speciation through natural selection.
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58) Diversification of mammals after the extinction of the dinosaurs is considered an adaptive radiation because a few mammal species rapidly evolved into most of the current mammalian lineages in a relatively short amount of time. This diversification was partially driven by the evolution of endothermic homeostasis in mammals, which is an example of A) allopatric speciation. B) reproductive isolation. C) a key innovation. D) hybridization.
59) Courtship for Anolis lizards involves the male displaying a dewlap (skin under the throat area) that varies in appearance based upon the species. Lizards that are found in darker, more shaded environments will have dewlaps that are lighter in color because they are more noticeable by potential mates. Which of the following mechanisms best explains how speciation is at work in this example? A) Postzygotic isolation B) Reinforcement C) Genetic drift D) Natural selection
60)
How many mass extinctions have been identified during the history of life on Earth? A) one B) two C) three D) four E) five
FILL IN THE BLANK. Write the word or phrase that best completes each statement or answers the question. 61) The_________blank _________blank model assumes that evolution occurs in spurts, between which there are long periods of stasis with little evolutionary change.
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62) The_________blank definition of species says that a species is a group of organisms that are reproductively isolated from other such groups.
63) The phenomenon where one original species diverges into many new species by occupying different habitats within a region is called _________blank _________blank.
64) The process by which related species become more different from each other, in order to reduce competition is called_________blank_________blank.
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Answer Key Test name: Chap 22_13e_Raven 1) FALSE Although the number of species experienced a leveling off period between 250 mya to 450 mya, there were fluctuations in the number of species that resulted in periods of mass extinctions. 2) [A, C]
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Clarify Question ● What is the key concept addressed by the question?● This question addresses punctuated equilibrium. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content ● What do you already know about punctuated equilibrium?● The punctuated equilibrium hypothesis argues that species have long periods of little or no evolutionary change (termed stasis), punctuated by quick bursts of evolutionary change. ● When natural selection is strong, evolutionary change can occur rapidly, so the “punctuated” part of the theory is not controversial. A more difficult question involves the long periods of stasis (the equilibrium): Why would species exist for thousands, or even millions, of years without changing? ● Most researchers now believe that a combination of stabilizing and oscillating selection is responsible for stasis. If the environment does not change over long periods of time, or if environmental changes oscillate back and forth, then stasis may occur for long periods. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Does the lack of intermediate fossils suggest that evolution proceeds steadily? No, because then you would expect to see the gradual change reflected in the fossil record. ● Does the lack of intermediate fossils suggest that evolution proceeds at a constant rate that is the same for all organisms? No, because you Version 1
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would expect to see intermediate fossils represented. ● Does the lack of intermediate fossils suggest that there is variability in the rate of evolution? Yes. Infrequent, rapid change means that intermediate forms may not become fossilized. ● Does the lack of intermediate fossils suggest that evolution occurs in spurts, alternating with long periods of little change? Yes. This can explain why intermediate forms were not well-represented in the fossil record. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that a lack of intermediate fossils suggests that change happens quickly, in keeping with the punctuated equilibrium model? 3) [A, B, C] 4) [B, D] 5) [A, B]
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Clarify Question ● What is the key concept addressed by the question?● This question addresses sympatric speciation. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content ● What do you already know about sympatric speciation?● Sympatric speciation is speciation that occurs without geographic separation. ● Sympatric speciation can occur either instantaneously or over the course of multiple generations. ● Instantaneous speciation generally involves polyploidy, and is typically found in plant species. ● Slower sympatric speciation can occur due to disruptive selection, causing a population to contain individuals exhibiting two different phenotypes. For instance, character displacement causes individuals to favor different resources, minimizing competition. This can lead eventually to speciation. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The pieces of evidence that support the occurrence of sympatric speciation are: ● Apple flies typically mate with apple flies, and hawthorn flies typically mate with hawthorn flies. ● Apple flies and hawthorn flies emerge from their hosts at different times of the year. ● Both of these indicate that the host preference is leading to less interbreeding between the two populations. Version 1
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that a host preference can drive sympatric speciation, particularly if the adults are ready to mate at different times, and typically mate only with flies on the same host? 6) [A, B, D]
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the biological species concept. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about the biological species concept?● In 1942 Ernst Mayr set forth the biological species concept, which defines species as “groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups.” ● In other words, a species is composed of populations whose members mate with each other and produce fertile offspring. Populations whose members do not mate with each other or who cannot produce fertile offspring are members of different species. ● Some have criticized the biological species concept because in recent years, biologists have detected much greater amounts of interspecies hybridization than was previously thought to occur between populations that seem to coexist as distinct biological entities. ● Botanists have always been aware that plant species often undergo substantial amounts of hybridization, so many botanists have long felt that the biological species concept is misnamed and only applies to animals. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Two snake species look different, but often form fertile hybrids. Would they be considered separate species? No, because they are not reproductively isolated. Version 1
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● Two tree species have different leaf shapes, but form hybrids in their overlapping ranges. Would they be considered separate species? No, because they are not reproductively isolated. ● Two skunk species look morphologically similar, but are unable to interbreed. Would they be considered separate species? Yes, because they are reproductively isolated. ● Two plant species have no gene flow between them. Would they be considered separate species? Yes, because they are reproductively isolated. ● Two bear species are able to breed in zoos, but have separate ranges in nature. Would they be considered separate species? Yes, because in nature they are reproductively isolated. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the biological species concept only distinguishes populations as separate species when they are reproductively isolated in nature? 7) [A, B, C] 8) [A, C] 9) [A, C] 10) [A, B, E] 11) [B, D] 12) [A, C, D]
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Clarify Question ● What is the key concept addressed by the question?● This question addresses gene flow before speciation. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content ● What do you already know about gene flow before speciation?● Gene flow may counter speciation. ● When incompletely isolated populations come together, gene flow immediately begins to occur between them. Surviving hybrids that reproduce with members of either population serve as a conduit of genetic exchange from one population to the other, and the two populations will tend to lose their genetic distinctiveness. ● Thus, a race ensues: Can complete reproductive isolation evolve before gene flow erases the differences between the populations? The outcome depends on the initial conditions and the particular species involved. ● When hybrids are LESS fit than the parents, selection would favor any alleles in the parental populations that prevented hybridization, because individuals that did not engage in hybridization would produce more successful offspring. ● In other words, selection would improve prezygotic isolating mechanisms until the two populations were completely reproductively isolated. This is called reinforcement. ● If hybrids are MORE fit than the parents, reinforcement is not likely to occur. Choose Answer Version 1
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● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Reinforcement of prezygotic isolating mechanisms will only occur when hybrids are less fit. ● In this case, hybrids are more fit. So, reinforcement is not likely to occur, and complete reproductive isolation and speciation are not likely to occur. ● Instead, there will likely be increased gene flow between the parental species. ● There may be evolution of a third species, or even extinction of one of both of the parental species, since they may be outcompeted by the hybrid. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that reinforcement of reproductive isolation requires that the hybrids are less fit than the parents? 13) [A, D]
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Clarify Question ● What is the key concept addressed by the question?● This question addresses sympatric speciation. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about sympatric and allopatric speciation?● A population can diverge into two species because the population has been separated geographically – this is allopatric speciation. ● Or, the population can diverge into separate species even when the populations are not separated – sympatric speciation. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Sympatric speciation can only occur when two populations are reproductively isolated, but not geographically isolated. ● The two examples here of geographically overlapping populations are the hybridizing sunflower species, and the flies that prefer a new host plant. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that sympatric speciation occurs when two Version 1
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populations that overlap geographically are reproductively isolated? 14) [A, B] 15) [A, D] The sixth mass extinction is currently underway and caused by human activities. The rebound is expected to be slow due to a large proportion of resources will be taken up already by human activities. 16) [A, B] 17) C 18) C 19) C 20) B 21) A 22) B 23) D 24) B 25) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses punctuated equilibrium. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about punctuated equilibrium?● The punctuated equilibrium hypothesis argues that species have long periods of little or no evolutionary change (termed stasis), punctuated by quick bursts of evolutionary change. ● When natural selection is strong, evolutionary change can occur rapidly, so the “punctuated” part of the theory is not controversial. A more difficult question involves the long periods of stasis (the equilibrium): Why would species exist for thousands, or even millions, of years without changing? ● Most researchers now believe that a combination of stabilizing and oscillating selection is responsible for stasis. If the environment does not change over long periods of time, or if environmental changes oscillate back and forth, then stasis may occur for long periods. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The unusual thing about the coelacanth is that it appears to have not changed over a long time. This is an example of stasis. ● Of the listed options, the one that predicts that species will sometimes stay the same is punctuated equilibrium. ● Punctuated equilibrium predicts that species may stay unchanged for long periods of time, then undergo bursts of rapid change. Version 1
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the coelacanth is an example of a species in stasis, which is a prediction of punctuated equilibrium? 26) A 27) C 28) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses reproductive isolation. ● What type of thinking is required?● This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. Gather Content ● What do you already know about reproductive isolation?● Populations are considered to be different species when the members are reproductively isolated from each other. ● Reproductive isolating mechanisms prevent genetic exchange between species. Some prevent the formation of zygotes – prezygotic isolating mechanisms. Others prevent the proper functioning of zygotes after they form – postzygotic isolating mechanisms. ● Prezygotic isolating mechanisms include ecological isolation, behavioral isolation, temporal isolation, mechanical isolation, and prevention of gamete fusion. ● Ecological isolation happens when two species occur in the same area, but use different portions of the environment and thus do not hybridize. ● Behavioral isolation is when related species differ in their courtship rituals, keeping these species distinct. ● Temporal isolation is when species reproduce in different seasons. ● Mechanical isolation is when the morphology of two species prevents mating. ● Sometimes gametes cannot fuse properly even when they meet. ● Postzygotic isolation occurs when hybrids between species are either inviable (poor at surviving) or infertile (unable to reproduce themselves).
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Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Is it likely that Darwin's finches are not different species according to the biological species concept? No. The biological species concept defines species as groups which are reproductively isolated. Having different mating songs is a mechanism of reproductive isolation. ● Is it likely that mating songs are primarily determined by the acoustics of different beaks? No, this doesn’t seem likely. Mating songs vary mostly in the pattern and tempo of the notes – a feature of brain circuits, not the beak. ● Is it likely that adaptation to different food sources occurred after reproductive isolation in Darwin's finches? Not likely. Reproductive isolation wouldn’t necessarily encourage two new species to diverge in their food preferences. However, different food preferences CAN set the stage for reproductive isolation to follow. ● Is it likely that adaptation to different food sources led to behavioral isolation in Darwin's finches? Yes. Having different niches – ecological isolation – limits the hybridization of two groups, causing reproductive isolation, and further behavioral isolation due to changes in mating songs. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. ● Did you recognize that preferences for different foods can lead to ecological isolation, which allows development of behavioral isolation barriers? Version 1
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29) C 30) B 31) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses reproductive isolation. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about reproductive isolation?● Populations are considered to be different species when the members are reproductively isolated from each other. ● Reproductive isolating mechanisms prevent genetic exchange between species. Some prevent the formation of zygotes – prezygotic isolating mechanisms. Others prevent the proper functioning of zygotes after they form – postzygotic isolating mechanisms. ● Prezygotic isolating mechanisms include ecological isolation, behavioral isolation, temporal isolation, mechanical isolation, and prevention of gamete fusion. ● Ecological isolation happens when two species occur in the same area, but use different portions of the environment and thus do not hybridize. ● Behavioral isolation is when related species differ in their courtship rituals, keeping these species distinct. ● Temporal isolation is when species reproduce in different seasons. ● Mechanical isolation is when the morphology of two species prevents mating. ● Sometimes gametes cannot fuse properly even when they meet. ● Postzygotic isolation occurs when hybrids between species are either inviable (poor at surviving) or infertile (unable to reproduce themselves). Choose Answer Version 1
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● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● In this example, it is the morphology that prevents mating – this is an example of mechanical isolation. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that when two groups have incompatible genitalia, we call it mechanical isolation? 32) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses reproductive isolating mechanisms. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about reproductive isolation?● Populations are considered to be different species when the members are reproductively isolated from each other. ● Reproductive isolating mechanisms prevent genetic exchange between species. Some prevent the formation of zygotes – prezygotic isolating mechanisms. Others prevent the proper functioning of zygotes after they form – postzygotic isolating mechanisms. ● Prezygotic isolating mechanisms include ecological isolation, behavioral isolation, temporal isolation, mechanical isolation, and prevention of gamete fusion. ● Ecological isolation happens when two species occur in the same area, but use different portions of the environment and thus do not hybridize. ● Behavioral isolation is when related species differ in their courtship rituals, keeping these species distinct. ● Temporal isolation is when species reproduce in different seasons. ● Mechanical isolation is when the morphology of two species prevents mating. ● Sometimes gametes cannot fuse properly even when they meet. ● Postzygotic isolation occurs when hybrids between species are either inviable (poor at surviving) or infertile (unable to reproduce themselves). Choose Answer Version 1
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● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● In this example of the lettuce species, they cannot cross because they bloom at different times of year. This is an example of temporal isolation – isolation based on timing. ● Since the pollen and egg never meet at all, a zygote never has a chance to form. Thus this is a prezygotic isolating mechanism. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that blooming at different times is an example of temporal isolation, which is a prezygotic mechanism of reproductive isolation? 33) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses reproductive isolation mechanisms. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about reproductive isolation mechanisms?● Populations are considered to be different species when the members are reproductively isolated from each other. ● Reproductive isolating mechanisms prevent genetic exchange between species. Some prevent the formation of zygotes – prezygotic isolating mechanisms. Others prevent the proper functioning of zygotes after they form – postzygotic isolating mechanisms. ● Prezygotic isolating mechanisms include ecological isolation, behavioral isolation, temporal isolation, mechanical isolation, and prevention of gamete fusion. ● Ecological isolation happens when two species occur in the same area, but use different portions of the environment and thus do not hybridize. ● Behavioral isolation is when related species differ in their courtship rituals, keeping these species distinct. ● Temporal isolation is when species reproduce in different seasons. ● Mechanical isolation is when the morphology of two species prevents mating. ● Sometimes gametes cannot fuse properly even when they meet. ● Postzygotic isolation occurs when hybrids between species are either inviable (poor at surviving) or infertile (unable to reproduce themselves). Choose Answer Version 1
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● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● In this example of the Hawaiian Drosophila species, they do not interbreed because they have different courtship rituals. This is a behavioral isolating mechanism. ● Without interbreeding, the sperm and egg never meet at all, so a zygote never has a chance to form. Thus this is a prezygotic isolating mechanism. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that when two species do not interbreed because of incompatible courtship rituals, this is a behavioral, prezygotic isolating mechanism? 34) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses adaptive radiation. ● What type of thinking is required?● This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. Gather Content ● What do you already know about adaptive radiation?● Adaptive radiation can occur different ways. ● In the classic model of adaptive radiation, a species colonizes several islands, and speciates allopatrically while the populations are separated. Later, the species may colonize the other islands as well. ● The species may evolve different adaptations while separated (allopatric) or after sharing the same island (sympatric). ● Two species sharing an island creates pressure to minimize their competition for resources. In the process of character displacement, natural selection favors those individuals that can use resources not used by the other species. Thus the two species will diverge in their favored resources and habitat. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The question states that the bird species are always more closely related to each other within an island than they are between any two islands. ● Therefore, does it make sense that each bird species evolved different adaptations in allopatry and then colonized the other islands? No, because then the closest related species would be found on different islands. Version 1
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● Therefore, does it make sense that each bird species became reproductively isolated by living on a different island, then later colonized the other islands and acquired new adaptations? No, because then the closest related species would be found on different islands. ● Therefore, does it make sense that many ancestral bird species colonized each island? No, because then the species on the same island would not be closely related. ● Therefore, does it make sense that one bird species colonized each island and then evolved into distinct species on that island through character displacement? Yes. That would fit with the finding that species within an island are most closely related. Character displacement is a mechanism by which species acquires different adaptations when living sympatrically. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. ● Did you recognize that if species on the same island are most closely related, they likely radiated from a progenitor on that island? 35) B 36) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses sympatric and allopatric speciation. ● What type of thinking is required?● This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. Gather Content ● What do you already know about sympatric and allopatric speciation?● A population can diverge into two species because the population has been separated geographically – this is allopatric speciation. ● Or, the population can diverge into separate species even when the populations are not separated – sympatric speciation. ● In the case of the snapping shrimp, there is a clear geographic separation – the Isthmus of Panama, that separates the Caribbean and Pacific Oceans. However, the question stem states that the species are actually most closely related to a sister species across the isthmus. How should we interpret this information? Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● According to the question, each species of snapping shrimp in Panama is most closely related to a sister species on the other side of the isthmus, rather than to the other species in the same ocean. ● Does it make sense that snapping shrimp in the Caribbean and the Pacific were never part of the same population? No. Their relatedness suggests that they were part of the same populations at one time. ● Does it make sense that the formation of the Isthmus of Panama had Version 1
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no effect on speciation in snapping shrimp? No. Clearly it would have been a big factor. ● Does it make sense that snapping shrimp species in each ocean diverged after the formation of the Isthmus of Panama? No. If that was the case, the species in each ocean would be most closely related to each other. ● Does it make sense that creation of the Panama Canal allowed interbreeding between populations of shrimp? No. The Panama Canal was only opened in 1914 – too recent to have affected the evolutionary relatedness of multiple shrimp species. ● Does it make sense that snapping shrimp species in each ocean diverged prior to the formation of the Isthmus of Panama? Yes. That would explain why the closest species are across the isthmus. The species in the same ocean had diverged long ago, but the species across the isthmus only diverged 3 million years ago when it formed. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. ● Did you recognize that the relatedness of different species can allow us to interpret when and how their speciation occurred? 37) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses speciation through polyploidy. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about speciation through polyploidy?● Instantaneous sympatric speciation occurs when an individual is born that is reproductively isolated from all other members of its species. This often occurs in plants due to their tolerance of polyploidy. ● Polyploid individuals can arise in two ways. In autopolyploidy, all of the chromosomes may arise from a single species (“self” polyploidy). This might happen due to an error in cell division that causes a doubling of chromosomes. ● A more common type of polyploid speciation is allopolyploidy, which may happen when two species hybridize (“other” polyploidy). ● Such individuals can reproduce asexually. Or, if the chromosomes spontaneously double to form a tetraploid, pairing would no longer be a problem in meiosis. They would be able to interbreed, and a new species would have been created. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● In this example, two different species contributed DNA to the new species, so it is an example of allopolyploidy. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that when two species hybridize and create a polyploid offspring, this is an example of instantaneous speciation by allopolyploidy? 38) B 39) E
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the biological species concept. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about speciation?● The biological species concept says that a species is composed of populations whose members mate with each other and produce fertile offspring. Conversely, populations whose members do not mate with each other or who cannot produce fertile offspring are said to be reproductively isolated and, therefore, are members of different species. ● Thus, populations are considered to be different species when the members are reproductively isolated from each other. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Do two different species have to eat different foods? Not necessarily. ● Do two different species have to live in different habitats? Not necessarily. ● Do two different species have to look different? Not necessarily. ● Do two different species have to have different mating behavior? Not necessarily. ● Do two different species have to be reproductively isolated? Yes! According to the biological species concept, that is the essential feature that defines two populations as different species. Reflect on Process Version 1
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● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the essential criterion that defines different species is that they are reproductively isolated? 40) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses reproductive isolation mechanisms. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about reproductive isolation?● Populations are considered to be different species when the members are reproductively isolated from each other. ● Reproductive isolating mechanisms prevent genetic exchange between species. Some prevent the formation of zygotes – prezygotic isolating mechanisms. Others prevent the proper functioning of zygotes after they form – postzygotic isolating mechanisms. ● Prezygotic isolating mechanisms include ecological isolation, behavioral isolation, temporal isolation, mechanical isolation, and prevention of gamete fusion. ● Ecological isolation happens when two species occur in the same area, but use different portions of the environment and thus do not hybridize. ● Behavioral isolation is when related species differ in their courtship rituals, keeping these species distinct. ● Temporal isolation is when species reproduce in different seasons. ● Mechanical isolation is when the morphology of two species prevents mating. ● Sometimes gametes cannot fuse properly even when they meet. ● Postzygotic isolation occurs when hybrids between species are either inviable (poor at surviving) or infertile (unable to reproduce themselves). Choose Answer Version 1
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● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The two bird species have different mating calls. This is a type of behavioral isolation. ● The two species occupy different habitats in nature. This is ecological isolation. ● When the two species hybridize, the hybrids are infertile. This is hybrid sterility. ● So the three isolating mechanisms are: ecological isolation, behavioral isolation, and hybrid sterility Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that different isolating mechanisms can be acting at the same time? 41) A 42) B 43) E 44) E 45) B 46) C 47) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses reproductive isolation. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about reproductive isolation?● Populations are considered to be different species when the members are reproductively isolated from each other. ● Reproductive isolating mechanisms prevent genetic exchange between species. Some prevent the formation of zygotes – prezygotic isolating mechanisms. Others prevent the proper functioning of zygotes after they form – postzygotic isolating mechanisms. ● Prezygotic isolating mechanisms include ecological isolation, behavioral isolation, temporal isolation, mechanical isolation, and prevention of gamete fusion. ● Ecological isolation happens when two species occur in the same area, but use different portions of the environment and thus do not hybridize. ● Behavioral isolation is when related species differ in their courtship rituals, keeping these species distinct. ● Temporal isolation is when species reproduce in different seasons. ● Mechanical isolation is when the morphology of two species prevents mating. ● Sometimes gametes cannot fuse properly even when they meet. ● Postzygotic isolation occurs when hybrids between species are either inviable (poor at surviving) or infertile (unable to reproduce themselves). Choose Answer Version 1
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● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● In this example of the different sea urchin species, the eggs and sperm cannot fuse due to incompatible chemical signals. ● This prevents a zygote (embryo) from even forming, so it is a prezygotic isolating mechanism. The incompatibility prevents gamete fusion (fusion of egg and sperm). Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that even eggs and sperm have to be compatible to allow mating to take place? 48) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses reproductive isolating mechanisms. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about reproductive isolation?● Populations are considered to be different species when the members are reproductively isolated from each other. ● Reproductive isolating mechanisms prevent genetic exchange between species. Some prevent the formation of zygotes – prezygotic isolating mechanisms. Others prevent the proper functioning of zygotes after they form – postzygotic isolating mechanisms. ● Prezygotic isolating mechanisms include ecological isolation, behavioral isolation, temporal isolation, mechanical isolation, and prevention of gamete fusion. ● Ecological isolation happens when two species occur in the same area, but use different portions of the environment and thus do not hybridize. ● Behavioral isolation is when related species differ in their courtship rituals, keeping these species distinct. ● Temporal isolation is when species reproduce in different seasons. ● Mechanical isolation is when the morphology of two species prevents mating. ● Sometimes gametes cannot fuse properly even when they meet. ● Postzygotic isolation occurs when hybrids between species are either inviable (poor at surviving) or infertile (unable to reproduce themselves). Choose Answer Version 1
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● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● In this example, the bird songs cannot attract the females of a different species. ● With no mating, a zygote does not form, so it is prezygotic. ● Since it is based on mating behavior, this is a behavioral isolation mechanism. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that when mating behavior is incompatible between different species, this is a prezygotic, behavioral isolation mechanism? 49) B 50) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses speciation through polyploidy. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about speciation through polyploidy?● Instantaneous sympatric speciation occurs when an individual is born that is reproductively isolated from all other members of its species. This often occurs in plants due to their tolerance of polyploidy. ● Polyploid individuals can arise in two ways. In autopolyploidy, all of the chromosomes may arise from a single species (“self” polyploidy). This might happen due to an error in cell division that causes a doubling of chromosomes. ● A more common type of polyploid speciation is allopolyploidy, which may happen when two species hybridize (“other” polyploidy). ● Such individuals can reproduce asexually. Or, if the chromosomes spontaneously double to form a tetraploid, pairing would no longer be a problem in meiosis. They would be able to interbreed, and a new species would have been created. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Allopolyploidy is a type of sympatric speciation – speciation that doesn’t require geographical isolation. Because the new polyploid offspring is reproductively isolated from the parental species, we can say that this speciation occurs almost instantaneously.
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that allopolyploidy allows speciation to occur almost instantly? 51) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses character displacement. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content ● What do you already know about character displacement?● Two species sharing a habitat have pressure to minimize their competition for resources. In the process of character displacement, natural selection favors those individuals that can use resources not used by the other species. Thus, the two species will diverge in their favored resources and habitat. This may be reflected in morphological features that allow them to take advantage of different resources. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Since the bird species are likely to compete for resources, there will be pressure for them to adapt via character displacement. ● The beak sizes should be more similar when allopatric (not overlapping in the same area) than when they are sympatric (present in the same area). Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to analyze the information given, using logic, to Version 1
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dissect the problem and determine the answer. ● Did you recognize that when competing species overlap, there may be character displacement? 52) C 53) D 54) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses natural selection and speciation. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content ● What do you already know about natural selection and speciation?● Natural selection often plays a role in speciation. ● As populations of a species adapt to different circumstances, they likely accumulate many differences that may lead to reproductive isolation. For example, if one population of flies adapts to wet habitats and another to dry areas, then natural selection will favor a variety of corresponding differences in physiological and sensory traits. These differences may produce ecological and behavioral isolation and may cause any hybrids the two populations produce to be poorly adapted to either habitat. Selection might also act directly on mating behavior. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The first step in evolution is the random occurrence of a mutation. The mutation in DNA produces variation in phenotype, which is what selection can act upon. ● The new phenotype may lead to reproductive isolation, by a variety of mechanisms. And reproductive isolation is the necessary prerequisite for speciation. ● The full sequence is: Mutation → Variation → Selection → Reproductive Isolation → Speciation. Version 1
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that mutations are the source of variation that selection acts upon? ● Did you recognize that reproductive isolation leads to speciation? 55) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses temporal isolation. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about temporal isolation?● Populations are considered to be different species when the members are reproductively isolated from each other. ● Reproductive isolating mechanisms prevent genetic exchange between species. Some prevent the formation of zygotes – prezygotic isolating mechanisms. Others prevent the proper functioning of zygotes after they form – postzygotic isolating mechanisms. ● Prezygotic isolating mechanisms include ecological isolation, behavioral isolation, temporal isolation, mechanical isolation, and prevention of gamete fusion. ● Temporal isolation is when species reproduce in different seasons. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Temporal refers to time. Think of the words “temporary”, “tempo”, or “contemporaneous”. ● The example in which the plants are isolated by time is the pair of plant species that bloom during different months. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that plants blooming during different months is an example of temporal isolation? 56) A 57) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses genetic drift. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about genetic drift?● Random changes may cause reproductive isolation. ● Given enough time, any two isolated populations will diverge because of genetic drift. ● In some cases, this random divergence may affect traits responsible for reproductive isolation, and speciation may occur. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● In this hypothetical example of the dogs on a distant planet, the astronaut-dogs are far away from Earth dogs, thus they are allopatric populations. ● The incompatibility is likely due to the small size of the population, rather than any natural selection against hybridization – in other words, due to random genetic changes from genetic drift. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that a small distant population is likely to become Version 1
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reproductively isolated by allopatric genetic drift? 58) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses adaptive radiation. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about adaptive radiation?● Adaptive radiations are particularly common in situations in which a species occurs in an environment with few other species and many available resources. ● One example is the creation of new islands through volcanic activity, such as the Hawaiian and Galápagos Islands. Another example is a catastrophic event leading to the extinction of most other species, a phenomenon termed mass extinction. ● Adaptive radiation can also result when a new trait, called a key innovation, evolves within a species allowing it to use resources or other aspects of the environment that were previously inaccessible. Classic examples of key innovation leading to adaptive radiation are the evolution of lungs in fish and of wings in birds and insects, both of which allowed descendant species to diversify and adapt to many newly available parts of the environment. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The evolution of endothermic homeostasis by the early mammals is an example of a key innovation. Reflect on Process Version 1
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● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that sometimes adaptive radiations are promoted by the evolution of a key innovation – a major evolutionary advance? 59) D
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Clarify Question ● What is the key concept addressed by the question?● Mechanisms that lead to speciation. ● What type of thinking is required?● The question is asking you to analyze a situation that leads to speciation in lizards. Gather Content/Choose Answer ● What do you already know about speciation? What other information is related to the question?● To solve this problem, you’ll need to remember that speciation can occur for many reasons. Usually some form of isolation is involved leading to reproductive isolation. Examples are ecological, temporal, mechanical, and behavioral isolations. When members of a species become isolated they are frequently also undergoing selection which encourages the speciation. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● If you figured out the correct answer, good job! If not, where did you go wrong? Did you think that genetic drift is at work in this example? While it is true that genetic drift can lead to speciation, this example is looking at changes in the environment rather than very small populations sizes. Did you think that postzygotic isolation is a possibility here? This is an example of a prezygotic isolation rather than a postzygotic isolation. How about reinforcement? That would apply if the lizards had hybrids that were less successful which isn’t mentioned in the question (and doesn’t apply here). That leaves natural selection which would explain that there is a mating preference for being able to clearly see colors of the male dewlaps. Version 1
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60) E 61) punctuated equilibrium 62) biological 63) adaptive radiation 64) character displacement
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Chapter 23 13e CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 1) A scientist sees that two insects share very similar wing patterns, but she suspects it may be an example of homoplasy. What would help her apply the principle of parsimony to determine their relationship? Check all that apply. A) Compare additional morphological traits B) Find other species with the same wing pattern C) Find other homoplastic traits in these two species D) Compare DNA sequences
2)
Select all of the following that can result in homoplasies. A) convergent evolution B) evolutionary reversals C) divergent evolution D) shared ancestry
3) Select the true statements describing why cladistics may not always be the best method for reconstructing phylogenies based on data from the DNA genome. A) The rate of evolution of the DNA genome is rapid. B) The assumptions of the principle of parsimony are not always met. C) Homoplasy often dominates the data sets. D) The number of character states for DNA is large.
4)
Choose the true statements about molecular clocks.
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A) Molecular clocks are only useful for slow changes over very long periods of time. B) Molecular clocks can be calibrated using fossil evidence. C) The rate of a molecular clock will differ between coding and noncoding DNA. D) Since all DNA is the same kind of molecule, all molecular clocks run at the same rate.
5) Choose the true statements about the evolution of complex characters, such as powered flight. A) Phylogenetic analysis using cladistics can help reveal the sequence leading to the evolution of a complex character. B) Usually a single mutation in one gene leads to the simultaneous appearance of the complex character. C) Often the initial stage in the evolution of a complex character was an adaptation to some unrelated selection pressure. D) The intermediate stages in the evolution of a complex character had no fitness advantage.
6)
Choose the true statements about the evolution of larval dispersal in marine snails.
A) The evolution of non-dispersing snails is likely to hinder speciation. B) Clades of non-dispersing snails are less species rich than those of dispersing snails. C) Loss of structures in the transition from dispersing to non-dispersing may inhibit evolutionary reversal. D) Possession of dispersing larvae is the ancestral state in snails. E) Cladistics shows that there are more instances of the transition from dispersing to nondispersing larvae than the reverse.
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7) The figure shows a cladogram of direct development versus development of a larval stage. Choose the true statements about the evolution of development in limpets.
A) Loss of structures in the transition from a larval stage to direct development prohibits evolutionary reversal. B) Direct development has evolved multiple times. C) Evolution always proceeds parsimoniously. D) Possession of a larval stage is the ancestral state in limpets.
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8) The figure shows the evolutionary diversification of the largest clade of herbivorous beetles with the group of plants on which they specialize. Choose the true statements about the evolution of species richness in herbivorous beetles.
A) Feeding on conifers evolved earlier than feeding on angiosperms. B) Feeding on cycads evolved earlier than feeding on angiosperms. C) Diversification of the angiosperms may have led to diversification of herbivorous beetles. D) The multiple, independent evolution of herbivory in beetles is closely linked to their great species richness.
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9) The figure shows the evolution of HIV and SIV. Choose the true statements about the evolution of HIV (Select all that apply).
A) All strains of HIV are included within clades with SIV strains. B) A strain of HIV is never more closely related to another strain of HIV than it is to a SIV strain. C) Humans acquired different subtypes of HIV from different primate hosts. D) HIV-1 group O is more closely related to SIV-chimpanzee than SIV-gorilla. E) All strains of SIV are included within clades with HIV strains.
10)
Phenotypic similarity does not always reflect evolutionary relationships due to A) variation in rates of evolutionary change among species. B) homoplasy. C) convergent evolution. D) outgrouping.
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MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 11) Characteristics between the branch points of a cladogram that are shared by all organisms above the branch point and are not present in any below it are called A) homologous characters. B) homoplastic characters. C) ancestral characters. D) derived characters. E) novel characters.
12) Characteristics that are present in organisms as a result of common evolutionary descent are said to be_________blank characteristics. A) homologous B) homoplastic C) adaptive D) derived E) ancestral
13) One day after a biology class four of your friends argue about the difference between phylogeny and systematics. Which friend is right? A) Friend A states that systematics and phylogenies are really the same, one is more recent than the other, but basically they are the same. B) Friend B says that systematics is the same as cladistics and cladistics is reconstructing clades, which ultimately lead to the development of phylogenies. C) Friend C argues that systematics is the actual collecting and cataloguing of specimens into museums that can be used later by scientists to construct clades and phylogenies. D) Friend D says that the way she remembers is that systematics is the reconstruction and study of phylogenies.
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14) What information would be most useful for determining the phylogenetic relationships between five species? A) A homoplasy shared by three of them. B) Two homoplasies, each shared by two of them. C) Three single-nucleotide changes shared by all five of them. D) Two synapomorphies shared by all five of them. E) A synapomorphy is shared by three of them.
15) Choose the true statement about the morphological data in the chart shown below. The "1" in the box means the trait is present and the "0" indicates that the trait is absent. (Note: All of the characteristics across the top of the columns are considered "TRAITS" for purposes of reading the chart.). TRAITS ORGANISM
Jaws
Lungs
Amniotic Membrane
Hair
No Tail
Bipedal
Lamprey
0
0
0
0
0
0
Shark
1
0
0
0
0
0
Salamander
1
1
0
0
0
0
Lizard
1
1
1
0
0
0
Tiger
1
1
1
1
0
0
Gorilla
1
1
1
1
1
0
Human
1
1
1
1
1
1
A) All organisms in this chart share all of the derived characteristics. B) Only the gorilla and humans share all of the derived characteristics. C) The lamprey is the only outgroup since it has none of the derived characteristics. D) The salamander and the tiger together are the outgroup because they only share two of the derived characteristics (jaws and lungs). E) The shark is the outgroup since it only has one of the derived characteristics (jaws).
16)
The study and reconstruction of phylogenies is
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A) evolution. B) systematics. C) taxonomy. D) taxidermy. E) cladistics.
17)
Derived character states shared by clade members are called A) ancestral traits. B) homoplasies. C) synapomorphies. D) plesiomorphies. E) symplesiomorphies.
18) The following are steps used to construct a cladogram that best reflects the evolutionary relationships of a group of species. Which step involves deciding which tree is most likely to have occurred, based on the fewest character state changes? A) Polarize the characters. B) Establish the character states. C) Gather data on characters to be used. D) Apply the principle of parsimony. E) Select an outgroup.
19)
Character states shared by the ancestor or outgroup of a clade are called A) derived traits. B) homoplasies. C) synapomorphies. D) plesiomorphies. E) symplesiomorphies.
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20) Birds, snakes, lizards, turtles, and crocodiles are all thought to share a common ancestor and several homologous traits. Assuming that this is true, these groups of animals and their common ancestor would represent A) a polyphyletic group. B) a monophyletic group. C) homoplastic convergence. D) an outgroup. E) a species cluster.
21) Evidence suggests that the crocodiles are more closely related to the birds than the turtles and snakes. If so, then including crocodiles, but not birds, in the Class Reptilia would make the Class Reptilia A) a monophyletic group. B) a paraphyletic group. C) a polyphyletic group. D) parsimonious. E) not homologous.
22)
A group is considered monophyletic if A) all members of the group share a common ancestor that is included in the group. B) not all descendants of the common ancestor are included. C) all members share homoplastic traits. D) the group does not contain the most recent common ancestor. E) it is the most parsimonious grouping.
23)
A group is considered paraphyletic if
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A) all members of the group share a common ancestor. B) not all descendants of the common ancestor are included. C) the common ancestor of the group is not included in the group. D) the group does not contain the most recent common ancestor. E) it is the most parsimonious grouping.
24)
A group is considered polyphyletic if A) all members of the group share a common ancestor. B) not all descendants of the common ancestor are included. C) all members share homoplastic traits. D) the group does not contain the most recent common ancestor. E) it is the most parsimonious grouping.
25)
The phylogenetic species concept (PSC) declares that a group is a species if it A) is reproductively isolated from other species. B) has evolved one or more of its own derived characters. C) looks different than other species. D) is allopatric. E) has no synapomorphies.
26)
Parental care in dinosaurs, crocodiles, and birds is an example of A) homoplasy caused by convergence. B) homoplasy caused by common descent. C) homoplasy caused by evolutionary reversal. D) homology caused by convergence. E) homology caused by common descent.
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27) The evolution of saber teeth in a number of groups of extinct carnivorous mammals is an example of A) homoplasy caused by convergence. B) homoplasy caused by common descent. C) homoplasy caused by evolutionary reversal. D) homology caused by convergence. E) homology caused by common descent.
28) The evolution of conducting tubes (sieve tubes) in land plants and brown algae is an example of A) homoplasy caused by convergence. B) homoplasy caused by common descent. C) homoplasy caused by evolutionary reversal. D) homology caused by convergence. E) homology caused by common descent.
FILL IN THE BLANK. Write the word or phrase that best completes each statement or answers the question. 29) _________blank is the science of classifying living things.
30) The biological specialty that deals with the reconstruction and study of phylogenies is called_________blank.
31) The behavior of parental care exhibited by dinosaurs is thought to be_________blank to this behavior in crocodiles and birds because phylogeny shows that these three groups share a common ancestor.
32) Saber teeth found in different groups of extinct carnivorous mammals are considered_________blank structures, as the fossil record shows that saber teeth evolved independently among the groups. Version 1
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33) Systematists often use DNA sequencing in_________blank, the study of the order of evolutionary events within a group sharing derived characters.
34) A_________blank group consists of the most recent common ancestor and all of its descendants.
35) A_________blank group consists of the most recent common ancestor and some of its descendants.
36)
A_________blank group does not contain the most recent common ancestor.
37) The principle of_________blank favors the hypothesis that requires the fewest assumptions.
38) A derived character that is shared by all members of a clade is called a_________blank of that clade.
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SECTION BREAK. Answer all the part questions.
39) ©McGraw-Hill Education
39.1) Based on the phylogeny shown, we can conclude that species 2 is most closely related to species A) 1. B) 3. C) 4. D) 5. E) 1 or 3 (can't tell).
39.2)
Based on the phylogeny shown, the outgroup would be species
A) 1. B) 2. C) 3. D) 4. E) 5.
39.3) Based on the phylogeny shown, the group of species including (2-5) can best be described as a
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A) clade. B) paraphyletic group. C) polyphyletic group. D) cladogram. E) synapomorphy
40) TRAIT SPECIES
A
B
C
D
E
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1
1
0
1
1
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1
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40.1) The table shows the distribution of traits (A-E) in six extant species (1-6). A "0" indicates the ancestral condition, while "1" indicates the derived condition. Which trait is least useful for understanding phylogenetic relationships within the group? A) A B) B C) C D) D E) E
40.2) The table shows the distribution of traits (A-E) in six extant species (1-6). A "0" indicates the ancestral condition, while "1" indicates the derived condition. Based on this data, which species would be considered the outgroup?
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A) 1 B) 2 C) 3 D) 4 E) 5
41) <p> ©McGraw-Hill Education
41.1) Consider the cladogram shown. Which pair of species shares the greatest number of derived characters (synapomorphies)? A) 4 and 2 B) 5 and 4 C) 6 and 1 D) 6 and 2 E) 5 and 2
41.2) Consider the cladogram shown. Based on this cladogram, which species has the greatest number of ancestral character states?
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A) 1 B) 2 C) 3 D) 4 E) 5
42) TRAIT SPECIES
A
B
C
D
E
1
1
0
0
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2
1
1
1
1
1
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1
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6
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1
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0
42.1) The table shows the distribution of traits (A-E) in six extant species (1-6). A "0" indicates the ancestral condition, while a "1" indicates the derived condition. Which trait has the greatest number of plesiomorphies? A) A B) B C) C D) D E) E
42.2) The table shows the distribution of traits (A-E) in six extant species (1-6). A "0" indicates the ancestral condition, while a "1" indicates the derived condition. Based on this data, which pair of species diverged most recently?
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A) 1 and 4 B) 2 and 3 C) 2 and 4 D) 6 and 4 E) 6 and 5
43) <p> ©McGraw-Hill Education
43.1) Consider the cladogram shown. Which pair of species shares the greatest number of derived characters (synapomorphies)? A) 1 and 4 B) 2 and 3 C) 2 and 4 D) 6 and 4 E) 6 and 5
43.2) Consider the cladogram shown. If we designate species 1 as the outgroup, which species has the greatest number of ancestral character states (plesiomorphies)?
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A) 2 B) 3 C) 4 D) 5 E) 6
44) TRAIT SPECIES
A
B
C
D
E
1
0
1
1
1
1
2
0
0
1
1
1
3
1
0
1
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1
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0
1
1
1
1
5
0
0
0
0
1
6
1
0
1
0
1
44.1) The table shows the distribution of traits (A-E) in six extant species (1-6). A "0" indicates the ancestral condition, and a "1" indicates the derived condition. Which trait is least useful for understanding phylogenetic relationships within the group? A) A B) B C) C D) D E) E
44.2) The table shows the distribution of traits (A-E) in six extant species (1-6). A "0" indicates the ancestral condition, and a "1" indicates the derived condition. Which species would you designate as the outgroup?
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A) 1 B) 4 C) 2 D) 3 E) 5
44.3) The table shows the distribution of traits (A-E) in six extant species (1-6). A "0" indicates the ancestral condition, and a "1" indicates the derived condition. Which pair of species shares the greatest number of derived characters (synapomorphies)? A) 1 and 4 B) 6 and 3 C) 6 and 1 D) 5 and 6 E) 5 and 1
44.4) The table shows the distribution of traits (A-E) in six extant species (1-6). A "0" indicates the ancestral condition, and a "1" indicates the derived condition. Which species has the greatest number of ancestral character states (plesiomorphies)? A) 1 B) 2 C) 3 D) 4 E) 5
45) TRAIT SPECIES
A
B
C
D
E
1
1
1
0
1
1
2
1
0
0
1
0
3
1
0
0
1
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1
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5
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1
1
6
0
0
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1
0
45.1) The table shows the distribution of traits (A-E) in six extant species (1-6). A "0" indicates the ancestral condition, and a "1" indicates the derived condition. Which trait is least useful for understanding phylogenetic relationships within the group? A) A B) B C) C D) D E) E
45.2) The table shows the distribution of traits (A-E) in six extant species (1-6). A "0" indicates the ancestral condition, and a "1" indicates the derived condition. Which species would you designate as the outgroup? A) 1 B) 2 C) 3 D) 4 E) 5 F) 6
45.3) The table shows the distribution of traits (A-E) in six extant species (1-6). A "0" indicates the ancestral condition, and a "1" indicates the derived condition. Which pair of species shares the greatest number of derived characters (synapomorphies)? A) 4 and 5 B) 2 and 4 C) 1 and 4 D) 3 and 4 E) 2 and 5
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45.4) The table shows the distribution of traits (A-E) in six extant species (1-6). A "0" indicates the ancestral condition, and a "1" indicates the derived condition. Which species has the greatest number of ancestral character states (plesiomorphies)? A) 1 B) 2 C) 3 D) 4 E) 5 F) 6
46) TRAIT SPECIES
A
B
C
D
E
1
0
0
1
0
0
2
1
0
1
0
1
3
1
0
1
0
1
4
1
1
1
0
0
5
1
1
1
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46.1) The table shows the distribution of traits (A-E) in six extant species (1-6). A "0" indicates the ancestral condition, and a "1" indicates the derived condition. Which trait is least informative of phylogenetic relationships within the group? A) A B) B C) C D) D E) E
46.2) The table shows the distribution of traits (A-E) in six extant species (1-6). A "0" indicates the ancestral condition, and a "1" indicates the derived condition. Which species has the fewest number of derived characters? Version 1
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A) 1 B) 2 C) 3 D) 4 E) 5 F) 6
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47.1) Consider the cladogram shown. Which pair of species shares the greatest number of derived characters (synapomorphies)? A) 1 and 3 B) 6 and 4 C) 6 and 5 D) 2 and 3 E) 6 and 3
47.2) Consider the cladogram shown. Based on this cladogram, which species has the greatest number of ancestral character states (plesiomorphies)?
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A) 1 B) 2 C) 3 D) 4 E) 5 F) 6
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48.1)
Based on the phylogeny shown, which species is not a tree but has seeds?
A) Psaronius B) Ginkgo C) Fern D) Rose E) Oak F) Pine
48.2)
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A) Tree B) Needles C) Flowers D) Seeds
48.3) Assume that the ancestor of this phylogeny had vascular tissue and chlorophyll. If this is true, which answer lists all key traits of a ginkgo? A) Vascular tissue, needles, tree, and chlorophyll B) Tree, needles, seeds, flowers C) Seeds, tree, vascular tissue, and chlorophyll D) Needles, tree, and seeds
48.4) Based on the phylogeny shown, indicate the groups that are monophyletic (Select all that apply). A) Rose and oak B) Pine, ginkgo, oak, and rose C) Fern, pine, and ginkgo D) Psaronius, fern, pine, ginkgo, oak, and rose
48.5) Based on the phylogeny shown, choose the true statement about evolutionary relationships. A) Ginkgo is more closely related to oak than rose. B) Oak is equally related to rose and pine. C) Fern is more closely related to pine than to rose. D) Fern is equally related to ginkgo and oak.
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49) ©McGraw-Hill Education
49.1) Based on the phylogeny shown, choose the true statements about evolutionary relationships (Select all that apply). A) A snake is more closely related to a newt than to a mouse. B) A newt is equally related to a snake and a chimp. C) A mouse is more closely related to a chimp than to a snake. D) A salamander is more closely related to a mouse than to a chimp.
49.2) Indicate the phylogenies that show the same relationship as the phylogeny above (Select all that apply).
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A)
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50) ©McGraw-Hill Education
50.1)
A frog would be added to the phylogeny above with a branch at point
A) A. B) B. C) C. D) D. E) E.
50.2) The common ancestor shared by mouse and gorilla is at point_________blank on the phylogeny shown. A) A B) B C) C D) D E) E
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Answer Key Test name: Chap 23_13e_Raven 1) [A, D] To apply the principle of parsimony, you need to have enough traits to compare that you can see which tree requires the fewest number of changes. Comparing the DNA sequences will also help determine the relationship between the two insects. 2) [A, B] 3) [A, B, C] 4) [B, C] 5) [A, C] 6) [C, D, E] 7) [B, D] 8) [A, C] 9) [A, B, C]
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. ● What key words does the question contain and what do they mean?● HIV is the Human Immunodeficiency Virus, the virus that causes AIDS in humans. ● SIV is the Simian Immunodeficiency Virus, which infects other primates. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. ● Each nested clade is defined by a new shared derived character. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Is HIV-1 group O more closely related to SIV-chimpanzee than SIV-gorilla? No. Look carefully at the cladogram, and you can see that HIV-1 group O forms a clade with HIV-1 group P and SIV-gorilla. Although the words SIV-chimpanzee are close, the actual branching on the diagram shows that that is more distantly related. ● Are all strains of SIV included within clades with HIV strains? No. Look to the clade of four strains on the far right – they form a clade without any closely related HIV strains. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Are all strains of HIV included within clades with SIV strains? Yes. Each of the six purple HIV strains lie in clades that also have at least one SIV strain. ● Is a strain of HIV never more closely related to another strain of HIV than it is to a SIV strain? Yes, this is correct. ● Did humans acquire different subtypes of HIV from different primate hosts? Yes, that is the most likely interpretation from these relationships – that HIV strains came from different primate SIV strains. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more
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desirable result?● This question asked you to choose true statements after interpreting a cladogram of HIV and SIV strains. ● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that a cladogram of viruses is like a cladogram of species? The strains that branch off the same nodes are most closely related.
10) [A, B, C] 11) D 12) E 13) D 14) E 15) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses outgroups and derived characters. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● Morphological data refers to features of the anatomy. Gather Content ● What do you already know about outgroups and derived characters?● The method of outgroup comparison is used to assign character polarity. To use this method, a species related to, but not a member of, the group under study is designated as the outgroup. ● When a group has multiple character states, and one of those states is seen in the outgroup, that state is considered to be ancestral and other states are derived. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Is it true that all organisms in this chart share all of the derived characteristics? No. There are six derived characters, and each species does not posses each derived character. ● Is it true that only the gorilla and humans share all of the derived characteristics? No, because in the chart humans have a derived character that gorillas lack – bipedalism. ● Is it true that the salamander and the tiger together are the outgroup because they only share two of the derived characteristics (jaws and lungs)? No. The only outgroup here to all the other organisms is the lamprey, which lacks the derived characters. ● Is it true that the shark is the outgroup since it only has one of the derived characteristics (jaws)? No. The only outgroup here to all the other organisms is the lamprey, which lacks the derived characters. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Is it true that the lamprey is the only outgroup since it shares none of the derived characteristics? Yes. The lamprey is the outgroup to the other organisms. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to choose the correct statement describing the species in the table. Version 1
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● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the lamprey is the outgroup, because it lacked the derived characteristics?
16) B 17) C 18) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladograms. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. ● What key words does the question contain and what do they mean?● A cladogram is a diagram that depicts a hypothesis of evolutionary relationships. ● Character states are the features of an organism, such as presence or absence of hair. Gather Content ● What do you already know about cladograms?● A cladogram is a diagram that depicts an evolutionary tree. ● A simple cladogram is a nested set of clades, each clade characterized by its own synapomorphies. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Does polarizing the characters decide which tree is most likely? No. Polarizing the characters refers to deciding which is the ancestral and the derived state. ● Does establishing the character states decide which tree is most likely? No. That means to decide what features to focus on, and what form they take in each species. ● Does gathering data on characters decide which tree is most likely? No. Again, this is about gathering information about the features of each species. Version 1
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● Does selecting an outgroup decide which tree is most likely? No. Selecting an outgroup means to pick the most distantly related species for establishing ancestral character states. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Does applying the principle of parsimony decide which tree is most likely? Yes. ● The principle of parsimony states that the best hypothesis is the one that requires the fewest assumptions (divergences). ● So the phylogeny that requires the fewest evolutionary events is considered the best hypothesis of phylogenetic relationships when using the principle of parsimony. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which step of creating a phylogenetic tree helps the researcher decide what is most likely. ● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that when using the principle of parsimony the most likely tree is the one with the fewest character state changes? 19) E 20) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses monophyly. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● The common ancestor of a group is the last organism that gave rise to all the members of the group – i.e., the organism at the bottom node on the tree of the group. ● Homologous traits are traits in different species that are the same, or very similar, because they arose from a common evolutionary origin. Gather Content ● What do you already know about monophyly?● A monophyletic group is a group that includes the most recent common ancestor of the group and all of its descendants. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Could you call this group of organisms and their ancestor a polyphyletic group? No, because that is a grouping that lacks the ancestor. ● Could you call this group of organisms and their ancestor a homoplastic convergence? No, that would imply that all the shared characters were due to coincidence, not due to common evolutionary origin. ● Could you call this group of organisms and their ancestor an outgroup? No, because that would be a distantly related species or group, relative to some other group of organisms being discussed. ● Could you call this group of organisms and their ancestor a species Version 1
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cluster? No, that is not the proper term. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Could you call this group of organisms a monophyletic group? Yes. A monophyletic group includes the most recent common ancestor of the group and all of its descendants. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked how you could describe the group including birds, snakes, lizards, turtles, and crocodiles, plus their ancestor. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the group of organisms sharing traits, and including the common ancestor, constitutes a monophyletic group. 21) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses monophyly. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● Class Reptilia is a traditional grouping of reptiles, but recent understanding has revealed that the grouping is not monophyletic, since birds should be included. Gather Content ● What do you already know about monophyly?● A monophyletic group is a group that includes the most recent common ancestor of the group and all of its descendants. Consider Possibilities ● Consider the different answer options. Which can you rule out?● In this case, would Class Reptilia be a monophyletic group? No, because a monophyletic group includes all the related members within the group. ● In this case, would Class Reptilia be a polyphyletic group? No, that would be a grouping of distant relatives, missing the common ancestor (such as bats and birds). ● In this case, would Class Reptilia be parsimonious? No. Something is only parsimonious if it describes the simplest, most likely evolutionary scenario. ● In this case, would Class Reptilia not be homologous? No, this is not the correct way to describe it. Only features can be homologous, if they are derived from a common evolutionary origin. Choose Answer Version 1
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● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● In this case, would Class Reptilia be a paraphyletic group? Yes, that is the correct term for a group that is missing one of its members. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to describe “Class Reptilia” defined without the inclusion of birds. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that when a member is missing from a grouping, that grouping is called paraphyletic? 22) A 23) B 24) D 25) B 26) E 27) A 28) A 29) Taxonomy 30) systematics 31) homologous 32) homoplastic 33) cladistics 34) monophyletic 35) paraphyletic 36) polyphyletic Version 1
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37) parsimony 38) synapomorphy 39) Section Break 39.1) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses phylogenetic trees. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● A phylogeny is an evolutionary tree which represents a hypothesis about patterns of relationship among species. Gather Content ● What do you already know about phylogenetic trees?● A phylogenetic tree is a way of diagramming a hypothesis about evolution. ● The tips of the twigs represent existing species. As one works down the tree, the joining of twigs and branches reflects the pattern of common ancestry back in time to the single common ancestor of all life. Consider Possibilities ● What other information is related to the question? Which information is most useful?● When a V-style tree is drawn with the Vs upwards, the highest nodes are the most recently-diverged species, and the lower nodes are older divergences between groups. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Since the groups with the highest node are most closely related, the closest relative of species 2 is species 3. Version 1
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which species is most closely related to species 2, based on a phylogenetic tree. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the most closely related species are drawn with nodes highest in the chart? 39.2) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses phylogenetic trees. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● A phylogeny is an evolutionary tree which represents a hypothesis about patterns of relationship among species. ● An outgroup is a distantly related species or group of species, relative to the group of species being focused on. The outgroup has ancestral characters, not the derived characters of the group of species in question. Gather Content ● What do you already know about phylogenetic trees?● A phylogenetic tree is a way of diagramming a hypothesis about evolution. ● The tips of the twigs represent existing species. As one works down the tree, the joining of twigs and branches reflects the pattern of common ancestry back in time to the single common ancestor of all life. Possibilities ● What other information is related to the question? Which information is most useful?● When a V-style tree is drawn with the Vs upwards, the highest nodes are the most recently-diverged species, and the lower nodes are older divergences between groups. Choose Answer Version 1
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● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The outgroup is most distantly related, compared to the other species. ● So the outgroup here would be the oldest, lowest node – group 1. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to identify the outgroup from a phylogenetic tree. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the outgroup would be the most distantly related to the other species, with the lowest node? 39.3) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses phylogeny. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● A phylogeny is an evolutionary tree which represents a hypothesis about patterns of relationship among species. Gather Content ● What do you already know about phylogenetic trees?● A phylogenetic tree is a way of diagramming a hypothesis about evolution. ● The tips of the twigs represent existing species. As one works down the tree, the joining of twigs and branches reflects the pattern of common ancestry back in time to the single common ancestor of all life. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Can you describe species 2-5 as a paraphyletic group? No. A paraphyletic group is a group that includes the most recent common ancestor of the group, but not all its descendants. ● Can you describe species 2-5 as a polyphyletic group? No. A polyphyletic group is a group that does not include the most recent common ancestor of all members of the group. ● Can you describe species 2-5 as a cladogram? No. The diagram itself can be described as a cladogram, but not species 2-5. Version 1
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● Can you describe species 2-5 as a synapomorphy? No. A synapomorphy is a derived character shared by members of a clade – but a synapomorphy is not what we call the clade itself. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Can you describe species 2-5 as a clade? Yes. ● A monophyletic group includes the most recent common ancestor of the group and all of its descendants. By definition, a clade is a monophyletic group. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked what term could best describe the species 2-5 in this phylogenetic tree? ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that a clade is a group containing all descendants of a common ancestor? 40) Section Break 40.1) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. ● What key words does the question contain and what do they mean?● Traits are features of an organism, used as data to build a tree. ● Extant species are still alive – i.e., not extinct. ● The ancestral condition of a trait is the original condition; the derived condition is the more newly evolved version. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters (synapomorphies) are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. Consider Possibilities ● What other information is related to the question? Which information is most useful?● To help construct a phylogeny, a trait must have derived characters shared between members of a group, and the ancestral character in the outgroup. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Version 1
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Since trait A is the same (derived) in all the species listed here, that trait cannot help us to understand their relationships. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which of the traits is least useful for understanding the phylogenetic relationships. ● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that a trait is only useful for building a cladogram if the trait varies (from ancestral to derived) in different species? ● Did you try drawing the cladogram for this data? 40.2) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. ● What key words does the question contain and what do they mean?● Traits are features of an organism, used as data to build a tree. ● Extant species are still alive – i.e., not extinct. ● The ancestral condition of a trait is the original condition; the derived condition is the more newly evolved version. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters (synapomorphies) are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. Consider Possibilities ● What other information is related to the question? Which information is most useful?● To help construct a phylogeny, a trait must have derived characters shared between members of a group, and the ancestral character in the outgroup. ● An outgroup carries ancestral characters. Choose Answer ● Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer?● Since an outgroup has ancestral characters, the best outgroup here is species 4, which has ancestral characters for all the useful traits (Trait A is shared by everybody and thus not useful). Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which species is the outgroup. ● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that the outgroup is the species with the most ancestral characters? ● Did you try drawing the cladogram for this data? 41) Section Break 41.1) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● A cladogram is a diagrammatic representation of a hypothesis about evolutionary relationships. ● A synapomorphy is a shared derived character. In other words, a newly-evolved trait is shared by a group of species. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters (synapomorphies) are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. Consider Possibilities ● What other information is related to the question? Which information is most useful? ● A cladogram is a set of nested clades, characterized by their synapomorphies (shared, derived characters). Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Since the nested clades are defined by synapomorphies, the species Version 1
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in the innermost nested clade must share more synapomorphies than more distantly related pairs of species. ● So species 6 and 1 share the most characters. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which two species share the most derived characters. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that a large number of shared characters indicates that two species are closely related? ● Did you remember that nodes are established by the appearance of a new derived character on one branch? 41.2) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● A cladogram is a diagrammatic representation of a hypothesis about evolutionary relationships. ● Ancestral character traits are those original versions of a trait, before they evolved into something new. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters (synapomorphies) are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. Consider Possibilities ● What other information is related to the question? Which information is most useful?● A cladogram is a set of nested clades, characterized by their synapomorphies (shared, derived characters). ● Since the nested clades are defined by synapomorphies, the species in the innermost nested clade must share more synapomorphies than more distantly related pairs of species. Choose Answer ● Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer?● The outermost species – the outgroup – must have the fewest synapomorphies and the most ancestral states (at least relative to the other species shown in this tree). Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which species has the most ancestral characters. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the outermost species in the cladogram is most distantly related to the others, and this “outgroup” has the most ancestral characters? 42) Section Break 42.1) E
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. ● What key words does the question contain and what do they mean?● Traits are features of an organism, used as data to build a tree. ● Extant species are still alive – i.e., not extinct. ● The ancestral condition of a trait is the original condition; the derived condition is the more newly evolved version. ● Plesiomorphies are ancestral characters. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters (synapomorphies) are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. Consider Possibilities ● What other information is related to the question? Which information is most useful?● A plesiomorphy is an ancestral character, so the question is asking which trait is most often in the ancestral condition in this data chart. Choose Answer ● Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer?● The ancestral state is marked as “0” in this chart, so the trait represented by the most plesiomorphies is E (with 4/6). Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which of the traits is represented by the most plesiomorphies. ● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that the trait with the most “0”s was the one with the most plesiomorphies? 42.2) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. ● What key words does the question contain and what do they mean?● Traits are features of an organism, used as data to build a tree. ● Extant species are still alive – i.e., not extinct. ● The ancestral condition of a trait is the original condition; the derived condition is the more newly evolved version. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters (synapomorphies) are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Evolutionary distance in a cladogram is indicated by a node defined by a new synapomorphy on one branch. ● If two species are not differentiated by a character, they must be closely related. Choose Answer Version 1
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● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Species 2 and 3 have five shared derived characters. They share more characters than the other species, so they must be most closely related. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which pair of species diverged the most recently. ● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that the species with the most shared derived traits are most closely related? 43) Section Break 43.1) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● A cladogram is a diagrammatic representation of a hypothesis about evolutionary relationships. ● A synapomorphy is a shared derived character. In other words, a newly-evolved trait shared by a group of species. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. Consider Possibilities ● What other information is related to the question? Which information is most useful?● A cladogram is a set of nested clades, characterized by their synapomorphies (shared, derived characters). Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Since the nested clades are defined by synapomorphies, the species in the innermost nested clade – the most closely related species in Version 1
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this cladogram – must share more synapomorphies than more distantly related pairs of species. ● So species 2 and 3 share the most characters. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which two species share the most derived characters. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that a large number of shared characters indicates that two species are closely related? So the two species closest on the tree have the most shared derived characters. ● Did you remember that nodes are established by the appearance of a new derived character on one branch? 43.2) E
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● A cladogram is a diagrammatic representation of a hypothesis about evolutionary relationships. ● Ancestral character traits are those original versions of a trait, before they evolved into something new. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram – a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. Consider Possibilities ● What other information is related to the question? Which information is most useful?● A cladogram is a set of nested clades, characterized by their synapomorphies (shared, derived characters). ● Since the nested clades are defined by synapomorphies, the species in the innermost nested clade – the most closely related species in this cladogram – must share more synapomorphies than more distantly related pairs of species. Choose Answer Version 1
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● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The outermost species – the outgroup – must have the fewest synapomorphies and the most ancestral states (at least relative to the other species shown in this tree). ● So species 6 is the one (besides the outgroup, 1) with the most ancestral states. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which species has the most ancestral characters. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the outermost species in the cladogram is most distantly related to the others, and this group has the most ancestral characters? 44) Section Break 44.1) E
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. ● What key words does the question contain and what do they mean?● Traits are features of an organism, used as data to build a tree. ● Extant species are still alive – i.e., not extinct. ● The ancestral condition of a trait is the original condition; the derived condition is the more newly evolved version. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters (synapomorphies) are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. Consider Possibilities ● What other information is related to the question? Which information is most useful?● To help construct a phylogeny, a trait must have derived characters shared between members of a group, and the ancestral character in the outgroup. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Version 1
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Since trait E is the same (derived) in all the species listed here, that trait cannot help us to understand their relationships. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which of the traits is least useful for understanding the phylogenetic relationships. ● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that a trait is only useful for building a cladogram if the trait varies (from ancestral to derived) in different species? ● Did you try drawing the cladogram for this data? 44.2) E
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● Traits are features of an organism, used as data to build a tree. ● Extant species are still alive – i.e., not extinct. ● The ancestral condition of a trait is the original condition; the derived condition is the more newly evolved version. ● The outgroup is the species (or group) with the most ancestral characters. Consider Possibilities ● What other information is related to the question? Which information is most useful?● The “1”s are derived characters; the ‘”0”s are ancestral characters. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The outgroup must be the species with the fewest synapomorphies and the most ancestral states (at least relative to the other species). ● That would be species 5 since it has the most “0” traits. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you Version 1
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astray? How can you revise your approach to produce a more desirable result?● This question asked which species is the outgroup. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the outgroup has the most ancestral characters? ● Did you try drawing the cladogram for this data? 44.3) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● Traits are features of an organism, used as data to build a tree. ● Extant species are still alive – i.e., not extinct. ● The ancestral condition of a trait is the original condition; the derived condition is the more newly evolved version. ● A synapomorphy is a shared derived character. In other words, a newly-evolved trait shared by a group of species. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. Consider Possibilities ● What other information is related to the question? Which information is most useful?● The “1”s are derived characters; the ‘”0”s are ancestral characters. Choose Answer ● Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer?● Species 1 and 4 both share the four derived characters B, C, D, and E. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which two species share the most derived characters. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the derived characters are marked with “1”s in the chart? 44.4) E
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● Traits are features of an organism, used as data to build a tree. ● Extant species are still alive – i.e., not extinct. ● The ancestral condition of a trait is the original condition; the derived condition is the more newly evolved version. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. Consider Possibilities ● What other information is related to the question? Which information is most useful?● The “1”s are derived characters; the ‘”0”s are ancestral characters. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Species 5 has four “0”s for traits B, C, D, and E, so it has the most Version 1
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ancestral states. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which species has the most ancestral characters. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the ancestral characters are marked with “0”s in the chart? 45) Section Break 45.1) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. ● What key words does the question contain and what do they mean?● Traits are features of an organism, used as data to build a tree. ● Extant species are still alive – i.e., not extinct. ● The ancestral condition of a trait is the original condition; the derived condition is the more newly evolved version. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters (synapomorphies) are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. Consider Possibilities ● What other information is related to the question? Which information is most useful?● To help construct a phylogeny, a trait must have derived characters shared between members of a group, and the ancestral character in the outgroup. Choose Answer ● Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer?● Since trait D is the same (derived) in all the species listed here, that trait cannot help us to understand their relationships. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which of the traits is least useful for understanding the phylogenetic relationships. ● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that a trait is only useful for building a cladogram if the trait varies (from ancestral to derived) in different species? ● Did you try drawing the cladogram for this data? 45.2) F
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● Traits are features of an organism, used as data to build a tree. ● Extant species are still alive – i.e., not extinct. ● The ancestral condition of a trait is the original condition; the derived condition is the more newly evolved version. ● The outgroup is the species (or group) with the most ancestral characters. Consider Possibilities ● What other information is related to the question? Which information is most useful?● The “1”s are derived characters; the ‘”0”s are ancestral characters. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The outgroup must be the species with the fewest synapomorphies and the most ancestral states (at least relative to the other species). ● That would be species 6 since it has the most “0” traits. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you Version 1
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astray? How can you revise your approach to produce a more desirable result?● This question asked which species is the outgroup. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the outgroup has the most ancestral characters? ● Did you try drawing the cladogram for this data? 45.3) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● Traits are features of an organism, used as data to build a tree. ● Extant species are still alive – i.e., not extinct. ● The ancestral condition of a trait is the original condition; the derived condition is the more newly evolved version. ● A synapomorphy is a shared derived character. In other words, a newly-evolved trait shared by a group of species. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. Consider Possibilities ● What other information is related to the question? Which information is most useful?● The “1”s are derived characters; the ‘”0”s are ancestral characters. Choose Answer ● Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer?● Species 4 and 5 both share all five derived characters. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which two species share the most derived characters. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the derived characters are marked with “1”s in the chart? 45.4) F
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● Traits are features of an organism, used as data to build a tree. ● Extant species are still alive – i.e., not extinct. ● The ancestral condition of a trait is the original condition; the derived condition is the more newly evolved version. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters (synapomorphies) are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. Consider Possibilities ● What other information is related to the question? Which information is most useful?● The “1”s are derived characters; the ‘”0”s are ancestral characters. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Species 6 has four “0”s for traits A, B, C, and E, so it has the most Version 1
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ancestral states. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which species has the most ancestral characters. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the ancestral characters are marked with “0”s in the chart? 46) Section Break 46.1) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. ● What key words does the question contain and what do they mean?● Traits are features of an organism, used as data to build a tree. ● Extant species are still alive – i.e., not extinct. ● The ancestral condition of a trait is the original condition; the derived condition is the more newly evolved version. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters (synapomorphies) are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. Consider Possibilities ● What other information is related to the question? Which information is most useful?● To help construct a phylogeny, a trait must have derived characters shared between members of a group, and the ancestral character in the outgroup. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Version 1
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Since trait C is the same (derived) in all the species listed here, that trait cannot help us to understand their relationships. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which of the traits is least useful for understanding the phylogenetic relationships. ● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that a trait is only useful for building a cladogram if the trait varies (from ancestral to derived) in different species? ● Did you try drawing the cladogram for this data? 46.2) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● Traits are features of an organism, used as data to build a tree. ● Extant species are still alive – i.e., not extinct. ● The ancestral condition of a trait is the original condition; the derived condition is the more newly evolved version. ● A synapomorphy is a shared derived character. In other words, a newly-evolved trait shared by a group of species. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. Consider Possibilities ● What other information is related to the question? Which information is most useful?● The “1”s are derived characters; the ‘”0”s are ancestral characters. Choose Answer ● Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer?● Species 1 has the least number of derived characters – “1”s. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which species has the fewest derived characters. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the derived characters are marked with “1”s in the chart? 47) Section Break 47.1) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● A cladogram is a diagrammatic representation of a hypothesis about evolutionary relationships. ● A synapomorphy is a shared derived character. In other words, a newly-evolved trait shared by a group of species. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. Consider Possibilities ● What other information is related to the question? Which information is most useful?● A cladogram is a set of nested clades, characterized by their synapomorphies (shared, derived characters). Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Since the nested clades are defined by synapomorphies, the species in the innermost nested clade must share more synapomorphies than Version 1
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more distantly related pairs of species. ● So species 6 and 5 share the most characters. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which two species share the most derived characters. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that a large number of shared characters indicates that two species are closely related? So the two most closely related species that are highest on the tree have the most shared derived characters. ● Did you remember that nodes are established by the appearance of a new derived character on one branch? 47.2) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● A cladogram is a diagrammatic representation of a hypothesis about evolutionary relationships. ● Ancestral character traits are those original versions of a trait, before they evolved into something new. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters (synapomorphies) are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. Consider Possibilities ● What other information is related to the question? Which information is most useful?● A cladogram is a set of nested clades, characterized by their synapomorphies (shared, derived characters). ● Since the nested clades are defined by synapomorphies, the species in the innermost nested clade must share more synapomorphies than more distantly related pairs of species. Choose Answer ● Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer?● The outermost species – the outgroup – must have the fewest synapomorphies and the most ancestral states (at least relative to the other species shown in this tree). ● In this case, that is species 1, that branches at the very base of the tree. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which species has the most ancestral characters. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the outermost species in the cladogram is most distantly related to the others, and this “outgroup” has the most ancestral characters? 48) Section Break 48.1) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● A phylogeny is a diagram that represents a hypothesis about evolutionary relationships. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters (synapomorphies) are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. ● Each nested clade is defined by a new shared derived character. These new characters are typically labeled on the branch. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Normally, a new shared derived character would define a clade. ● Here in this example, the feature ”tree” is shown as a character on three distantly related branches. There must have been many other characters that led researchers to believe that the plants became “trees” by convergent evolution. Choose Answer Version 1
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● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The rose is shown above two character labels: “Seeds” and “Flowers”, but not above “Tree”. ● So the rose is the member of this phylogeny that is not a tree but does have seeds. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which species shown in the phylogeny has seeds but is not a tree. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the gray labels marked characters? 48.2) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● Homoplastic means that a character arose by convergent evolution. It is not a synapomorphy because it arose in separate unrelated lineages. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters (synapomorphies) are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. ● Each nested clade is defined by a new shared derived character. These new characters are typically labeled on the branch. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Are needles, flowers, or seeds homoplastic? No, because they each only appear once on the tree. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The character “tree” is homoplastic, because it appears in different Version 1
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clades on the tree. ● There must have been a preponderance of other characters that made it obvious that trees are the result of convergent evolution in multiple lineages. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which character is homoplastic. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the feature “tree” in the phylogeny is homoplastic, since it appears in multiple clades? 48.3) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. ● What key words does the question contain and what do they mean?● The ancestor of the phylogeny would be the extinct plant species at the base of the diagram. ● Vascular tissue and chlorophyll are features that all vascular plants have. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters (synapomorphies) are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. ● Each nested clade is defined by a new shared derived character. These new characters are typically labeled on the branch. Consider Possibilities ● What other information is related to the question? Which information is most useful?● By tracing the branches from the bottom to the ginkgo branch, you can find which features the ginkgo must have. Choose Answer ● Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer?● Since the question posits that all the species have vascular tissue and chlorophyll, ginkgo has those. ● In addition, ginkgo has seeds and is a tree – the labels shown on the branches below. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked what features ginkgo has. ● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that you could trace the evolution of features by moving from the bottom to the top of the tree? 48.4) [A, B, D]
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Clarify Question ● What is the key concept addressed by the question?● This question addresses monophyly. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● A monophyletic group consists of the most recent common ancestor and all of its descendants. Gather Content ● What do you already know about monophyly?● True clades are monophyletic – they are groups including the most recent common ancestor and all of its descendants. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Do “fern, pine, and ginkgo” form a monophyletic group? No, because it excludes the equally related Psaronius, oak, and rose. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Do “rose and oak” form a monophyletic group? Yes, because they share the synapomorphy “flowers” and form a clade together. ● Do “pine, ginkgo, oak, and rose” form a monophyletic group? Yes, because they share the synapomorphy “seeds” and form a clade together. ● Do “Psaronius, fern, pine, ginkgo, oak, and rose” form a monophyletic group? Yes, because they form a clade together as Version 1
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indicated on the cladogram (although their synapomorphy is not indicated here). Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which groupings are monophyletic. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the question was asking which are true clades? 48.5) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● A phylogeny is a diagram describing a hypothesis about evolutionary relationships. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters (synapomorphies) are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. ● Each nested clade is defined by a new shared derived character. These new characters are typically labeled on the branch. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Is ginkgo more closely related to oak than rose? No, it is equally related to them both, since they are members of the same clade. ● Is oak equally related to rose and pine? No, oak is a member of the same clade with rose, so it is more closely related to rose. ● Is fern more closely related to pine than to rose? No, it is equally related to them both, since they are members of the same clade. Version 1
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Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Is it true that fern is equally related to ginkgo and oak? Yes, because they are members of the same distant clade. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to choose the true statement about the cladogram. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that a species is equally related to all the species of a distant clade? 49) Section Break 49.1) [B, C]
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● A phylogeny is a diagram describing a hypothesis about evolutionary relationships. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters (synapomorphies) are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. ● Each nested clade is defined by a new shared derived character. These new characters are typically labeled on the branch. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Is a snake more closely related to a newt than to a mouse? No. Snakes are within the same clade as mice. ● Is a salamander more closely related to a mouse than to a chimp? No, because mice and chimps are both members of the same distantly related clade. Choose Answer ● Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer?● Is a newt equally related to a snake and a chimp? Yes, because snakes and chimps are both members of the same clade. ● Is a mouse more closely related to a chimp than to a snake? Yes, because mice and chimps are members of the same clade. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to choose the true statements based on interpreting the phylogeny. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that looking at the nested clades of a phylogeny can help you to understand how closely related species are? 49.2) [A, D]
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladograms. ● What type of thinking is required?● This question is asking you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. ● What key words does the question contain and what do they mean?● A phylogeny is a diagram describing a hypothesis about evolutionary relationships. Gather Content ● What do you already know about cladograms?● Cladograms are diagrams that represent hypotheses about evolutionary relationships. ● Cladograms are constructed according to the rules of cladistics. Consider Possibilities ● What other information is related to the question? Which information is most useful?● The important thing about a cladogram is the branching pattern and location of nodes. So if the species branch off with a different pattern, they do not represent the same evolutionary tree. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Two of the cladograms are the same except that a clade is rotated above a node. The order of listed species doesn’t matter as long as the branching pattern is the same, so these represent the same tree. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which cladograms showed the same hypothesis as the original cladogram. ● The question required you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. ● Did you recognize that you can “spin” the branches above a node on the cladogram, and it is the same cladogram?
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● A phylogeny is a diagram describing a hypothesis about evolutionary relationships. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters (synapomorphies) are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. ● Each nested clade is defined by a new shared derived character. These new characters are typically labeled on the branch. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Do frogs belong with the reptiles? No, frogs have many more features in common with the other amphibians, salamanders and newts. ● Do frogs belong with the mammals? No, frogs have many more features in common with the other amphibians, salamanders and newts. ● Do frogs belong with the clade of reptiles plus mammals? No, Version 1
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frogs have many more features in common with the other amphibians, salamanders and newts. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Do frogs belong with the clade of amphibians, with salamanders and newts? Yes, they share many characteristics with these other amphibians. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked where a frog should be added to the tree. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that frogs are amphibians, and they share many features with salamanders and newts? 50.2) E
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cladistics. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● The common ancestor is the ancestor that existed just before the split of the branches. ● A phylogeny is a diagram describing a hypothesis about evolutionary relationships. Gather Content ● What do you already know about cladistics?● Cladistics is the method used to construct a cladogram — a graphically represented hypothesis of evolutionary relationships. ● Only shared derived characters (synapomorphies) are useful for inferring phylogenies, and they must be contrasted to an outgroup that has the ancestral characters. ● Each nested clade is defined by a new shared derived character. These new characters are typically labeled on the branch. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Would the common ancestor of mice and gorillas be below salamanders and newts? No way, those are too distantly related. ● Would the common ancestor of mice and gorillas be below snakes and lizards? No way, those are too distantly related. ● Would the common ancestor of mice and gorillas be at C, below Version 1
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the clade of reptiles and mammals? That is an ancestor of mice and gorillas, but not the most recent common ancestor because it was the ancestor of many other species. ● Would the common ancestor of mice and gorillas be at D, along the branch to mice? No, because that branch did not give rise to gorillas. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Would the common ancestor of mice and gorillas be at E? Yes, because that is the node below the mammal groups. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you where the common ancestor of a mouse and gorilla would be on the tree. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that gorillas, mice and chimps are all mammals?
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Chapter 24 13e CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 1) When a segment of DNA duplicates, causing two copies of a gene to be present in the chromosome, the duplicate copy could possibly (Check all that apply) A) lose function due to mutation. B) become an ortholog. C) gain a new function due to mutation. D) become a pseudogene. E) become a centromere.
2) The types of human genes most likely to be duplicated, resulting in multiple copies, are... (Choose two.) A) cellular housekeeping genes. B) immune system genes. C) genes for cell surface receptors. D) genes for controlling basic metabolism.
3)
Choose all the true statements about orthologs and paralogs. A) Orthologs in different species will often have the same function. B) Both orthologs and paralogs result from single nucleotide changes. C) Paralogs are found in more than one copy in the same species. D) Paralogs can take on new functions after duplication. E) Paralogs are nonfunctional, and orthologs are functional.
4)
Choose the true statements about the human and pufferfish genomes.
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A) The human genome has much more DNA than the pufferfish genome, but a similar number of genes. B) About 25% of the human genes have no counterpart in the pufferfish genome. C) Being ancestral to humans, the pufferfish genome has more repetitive DNA than the human genome does. D) The pufferfish genome has twice the amount of DNA as the human genome does.
5)
Choose the true statements about the human and mouse genomes.
A) The human genome shares almost all of its genes with the mouse genome. B) A comparison of genomes confirms that mice and humans shared a common ancestry more recently than humans and pufferfish. C) Very few genes are conserved in the two genomes. D) Little rearrangement of genes has occurred in the two genomes.
6)
Choose the true statements about the human and chimpanzee genomes.
A) A comparison of genomes confirms that humans and chimpanzees are closely related species. B) About 14% of genes are similar between the genomes. C) There is about 1.4% divergence in single-site substitutions between the genomes. D) More similarity exists between human and mouse genomes than between human and chimpanzee. E) The genome size is about twice as big in humans as in chimpanzees.
7) Choose the true statements about the genomes of plants (especially Arabidopsis and rice), animals, and fungi.
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A) Plants, animals, and fungi share most of the same genes for intermediary metabolism, genome replication, and protein synthesis. B) "Plant" genes include those coding for photosynthetic pathways and morphology. C) Plants generally have smaller genomes than those of animals and fungi. D) Rice has fewer genes than humans.
8)
What are likely outcomes for a pair of duplicated genes? (Choose all that apply.) A) One copy becomes a nonfunctional pseudogene. B) One copy acquires a novel function. C) Gene conflict causes both copies to be lost from the genome. D) Each copy specializes for just one of the original gene's functions.
9)
Choose the true statements about pseudogenes. A) Premature stop codons can produce pseudogenes. B) Missense mutations can produce pseudogenes. C) Pseudogenes have DNA sequences very similar to a functional gene. D) Pseudogenes result from horizontal gene transfer.
10) Genome sequencing of our human ancestor, Neanderthals ( Homo neanderthalensis), revealed that Neanderthals have a FOXP2 gene with the same two amino acid changes observed in H. sapiens FOXP2. What can be concluded based on this finding? (Check all that apply) A) Neanderthals evolved from H. sapiens. B) H. sapiens evolved from Neanderthals. C) Neanderthals may have had the ability to use language. D) These two amino acid changes arose prior to the common ancestor of Neanderthals and H. sapiens. E) Verbal speech was impossible for Neanderthals.
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11) How can analysis of mammalian genomes be used to detect and treat human disease? Check all that apply. A) The genomes of the mammalian relatives of humans are the best targets for discovering new treatments for human diseases. B) Comparing the genomes of parasite and host is likely to reveal good drug targets to eliminate the parasite without harming the host. C) A comparison of mouse and human genomes would help reveal functions for previously unidentified human genes. D) A comparison of human and mouse genomes would help observe DNA sequences that evolved prior to the evolution of mammals.
12) Hox genes are a family of transcription factors that regulate development throughout the animal kingdom. Studies of Hox genes in mice and Drosophila showed that many Hox genes are conserved between both species, and several Hox genes duplicated into new genes with novel functions within mice. Some Hox genes have even lost all function. Hox genes provide an example of which of the following? Check all that apply. A) orthologs B) paralogs C) heterologs D) pseudogenes
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 13) The breast cancer gene BRCA1 has a very similar sequence in humans, mice, and gorillas, due to its origination in a common ancestor. The BRCA1 genes in these species are examples of _________blank. A) orthologs B) paralogs C) polyploidy D) synteny
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14) Except in rare cases, genes are usually passed from generation to generation within a species. This process is called: A) horizontal gene transfer B) vertical gene transfer C) transgenesis D) synteny
15)
If a gene is found in different groups, it is said to be A) active. B) variable. C) conserved. D) associational. E) endogenous.
16) Using the sequencing results for genomes from each of the kingdoms, it is currently possible A) to explore genetic differences between organisms in detail, by examining the DNA sequence. B) to build, from scratch, complex organisms with trans-kingdom genomes. C) to understand the relationship between each gene and each organism's unique set of traits. D) to design humans with a variety of inter-kingdom abilities built into their DNA.
17)
Choose the true statement about the human genome and the tiger pufferfish genomes. A) Essentially all the human genes have nearly identical counterparts in pufferfish. B) The order of genes along the chromosomes in both species is essentially identical. C) Both species have about the same amount of introns and "nonsense" sequences of
DNA. D) About 25% of human genes are unique when compared to the tiger pufferfish genome.
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18) One of the ways that two species can be compared, and information about the genetic basis of human diseases extracted, is by using their sequenced genomes and A) looking at the allelic differences. B) investigating the introns. C) looking at the conserved sequences. D) exchanging genomic information between them.
19)
One of the reasons that pufferfish are a good species to compare to humans is because
A) it is so easy to hybridize the two and investigate the consequences. B) they are so distantly related that it's easy to distinguish mutually conserved sequences. C) the introns are often identical. D) of the rapid response time in pufferfish to artificial selection. E) they have been separated for so many millions of years and yet the gene sequence is almost identical.
20)
Comparisons of human and mouse genomes reveals
A) they have widely different numbers of genes, and share only a few more genes than humans and pufferfish. B) the differences between humans and mice are mainly the introns. C) they have very little in common. D) there are more differences in protein coding DNA than in noncoding DNA. E) the genomes are very similar, but mice have many more active olfactory receptor genes.
21) Genes are found in the same order for large stretches of the X chromosome in the rat and mouse genomes, indicating
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A) occurence of aneuploidy. B) formation of pseudogenes. C) conservation of synteny. D) conservation of neoteny.
22) The best explanation for the differences between humans and chimps despite the similarities in their gene-coding sequences is A) the differences in exons between their genomes. B) the differences in the introns between their genomes. C) the telomeres of humans contain important sequences not present in chimps. D) differences in gene expression between species.
23) Genome sequencing of the parasitic protist Plasmodium falciparum has been completed. One of the results is A) Plasmodium is highly genetically similar to its host, Anopheles. B) Plasmodium is highly genetically similar to its host, Drosophila. C) Plasmodium has a chloroplast-like apicoplast that could be targeted by drugs. D) Plasmodium produces fatty acids that are similar to ones found in humans and could be targeted by drugs.
24) The genomes of Arabidopsis thaliana, and rice, Oryza sativa, have been sequenced. The findings include
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A) the genome for each is almost identical, indicating that they diverged in the fairly recent past. B) they each have high copy numbers for several gene families, probably indicating episodes of polyploidy and/or segmental duplication. C) repetitive DNA, including retrotransposons, was a very small proportion of both genomes. D) more than 90% of the genes in each were particular to plants and not found in animal or fungal genomes.
25)
Some of the olfactory receptor (OR) genes in humans
A) have been inactivated, reducing our olfactory capabilities compared to other primates. B) have been activated, enhancing our olfactory sense compared to other primates. C) have duplicated more frequently, resulting in increased paralogs compared to other primates. D) have been conserved more rigidly, resulting in increased orthologs compared to other primates.
26) Many genes in the human genome are no longer expressed because mutations have introduced stop codons within the coding sequence or transposons have disrupted gene function. These genes are now considered A) pseudogenes. B) orthologs. C) paralogs. D) homologues.
27)
Today, gene swapping between two species is
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A) impossible, but it happened frequently in the distant past. B) infrequent butpossible; it happened more often in the distant past. C) much more frequent compared to in the distant past. D) only possible if they are in the same family of organisms, such as lions and tigers.
28)
The human genome
A) has no foreign DNA because it is excised by DNase. B) has a very small amount of foreign DNA, mostly in the end caps (telomeres) of chromosomes. C) has a lot of foreign DNA, mostly in the end caps (telomeres) of chromosomes. D) has a lot of foreign DNA scattered throughout the genome, including transposons.
29) Choose the correct sequence of events involving allopolyploidy that gave rise to modern tobacco. A) hybridization, chromosome doubling, duplicate gene loss B) hybridization, duplicate gene loss, chromosome doubling C) chromosomedoubling, hybridization, duplicate gene loss D) duplicate gene loss, hybridization, chromosome doubling
30) Choose the true statement about the role of polyploidization in the evolution of plant genomes. A) Jumping of transposons is most common many generations after a polyploidization event. B) Genome downsizing following allopolyploidy usually affects the participating hybrids equally. C) Genome downsizing following allopolyploidy results mainly from duplicate gene loss. D) Crop plants rarely show evidence of polyploidization events.
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31) Choose the most important reason that humans have a reduced sense of smell compared with other mammals. A) Many olfactory receptors became pseudogenes in the human lineage. B) Humans have more conservation of synteny. C) Humans have more aneuploidy. D) Humans are susceptible to coronaviruses and other mammals aren't. E) Humans lost all olfactory receptor (OR) genes.
32)
Horizontal gene transfer A) is also called vertical gene transfer. B) involves sharing genes between plants and animals. C) was common early in the history of life, and continues at a low level today. D) is another term for GMOs. E) makes molecular phylogenies impossible to construct.
33)
Choose the true statement about foreign DNA in the human genome. A) Most of the foreign DNA in the human genome is ancient. B) Most of the foreign DNA in the human genome is coding DNA. C) Like the Drosophila genome, the human genome is constantly eliminating its foreign
DNA. D) New foreign DNA is regularly entering the human genome.
34)
The best explanation for why a mouse develops into a mouse and not a human is A) most of the coding genes are different. B) most of the non-coding genes are different. C) gene expression differs. D) the genes are mostly the same but have been rearranged. E) synteny has not been conserved.
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35) What type of genes would be most likely to exhibit different expression patterns between humans and non-human primates, such as gorillas? A) Genes controlling brain development B) Genes controlling mammary gland development C) Genes controlling lung development D) Genes controlling heart development
36) Recent research has suggested that some pseudogenes and non-protein-coding DNA code for RNAs that affect transcription of coding regions. This suggests that A) pseudogenes code for proteins. B) non-protein-coding DNA has no function. C) non-protein-coding DNA may regulate gene expression. D) pseudogenes have no function.
37)
Choose the true statement about genome size and gene number in animals.
A) There is a strong correlation between the number of genes and genome size. B) Much of the extra DNA in humans is in the form of exons. C) The pufferfish has a larger genome than humans and more genes. D) Genome size differences depend to a large extent on the amount of noncoding DNA present.
38) Plant species regularly hybridize in nature, but only some crosses result in new polyploid species. Of the crosses below, if each one occurred, which would be most likely to result in a new stable polyploid species?
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A) A cross between a 2n gamete and a 1n gamete, forming a 3n hybrid. B) A cross between a 4n gamete and a 1n gamete, forming a 5n hybrid. C) A cross between a species with a CC genome and a species with a DD genome, forming a hybrid with a CD genome. D) A cross between a species with a BB genome and a species with a DD genome, followed by a doubling of chromosomes, forming a hybrid with a BBDD genome.
39) Three human diseases in the tropics are caused by protozoan parasites -- Chagas disease, African sleeping sickness, and Leishmania. Looking at the table of homologous genes found in different species, which gene would be best to target for the development of a drug to cure disease without harming the patient? (+ indicates that a homologous gene is present; - indicates that no homologous gene is present). Chagas' parasite
Sleeping sickness parasite
Leishmaniasis parasite
Humans
gene A
+
-
+
-
gene B
+
+
+
+
gene C
-
+
+
-
gene D
+
+
+
-
gene E
-
-
-
+
A) Gene A B) Gene B C) Gene C D) Gene D E) Gene E
40) What is a common finding from the genome analysis of endangered species such as Tasmanian devils?
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A) Numerous gene duplications because of evolution "speeding up". B) Large numbers of deleterious transposons. C) Low genetic diversity due to small population size. D) Aneuploidy and polyploidy.
41) During meiosis, a hexaploid hybrid plant spontaneously eliminates one set of chromosomes (eliminates 1 n). What is the most likely result of this deletion? A) The hybrid will no longer be able to reproduce. B) The hybrid will be able to reproduce with one of the parental species. C) The hybrid will no longer be polyploid. D) The hybrid will be able to reproduce only by self-fertilization.
42) Petrels (a flying and diving seabird) are thought to be one of the closest living relatives to penguins. What type of genes would be most likely to exhibit different expression patterns between these species? A) Genes controlling skeletal development. B) Genes regulating the digestive tract. C) Genes regulating salt water tolerance. D) Genes controlling organ development.
43) Crop sunflowers are attacked by many fungal pathogens, such as downy mildew and Sclerotinia, resulting in economic losses of millions of dollars per year. What genes would be best to target for the development of new fungus-killing crop treatments (fungicides)?
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A) Genes encoding chitin proteins that are shared by downy mildew and Sclerotinia, but absent in sunflower and humans. B) Genes encoding growth proteins that are shared by downy mildew, Sclerotinia, and sunflower, but absent in humans. C) Genes encoding metabolite proteins that are shared by downy mildew, Sclerotinia, and humans, but absent in sunflower. D) Genes encoding basic development proteins that are shared by downy mildew, Sclerotinia, sunflower, and humans.
44) What would be the best strategy to pinpoint the genetic differences that are responsible for the unique features ofHomo sapiens? A) Compare the human genome with other vertebrate genomes. B) Compare the human genome with other mammalian genomes. C) Compare the human genome with other primate genomes. D) Compare the human genome with other ape genomes.
45) If you were researching genetic differences between humans and other mammals, which set of genes would be LEAST likely to have important differences? A) MHC and immune system genes B) Olfactory receptor genes C) Genes for basic cellular metabolism functions D) Genes for brain development
46)
What best describes the basis of differences in genome size in different organisms?
A) There is a rigid relationship between organism complexity and genome size. B) Genome size is affected both by polyploidization and also how much noncoding DNA is maintained over time. C) Genome size is mainly determined by polyploidization. D) Genome size is mainly affected by the number of transposons in the genome.
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47)
What is the range of Neanderthal DNA found in individual humans? A) 0 to 0.1% B) 0 to 3% C) 5 to 10% D) 25 to 50%
48)
After a plant becomes polyploid, what often occurs? A) Some of the duplicated genes are lost or mutated. B) The plant maintains both complete genomes. C) The plant gives rise to two types of progeny, that match each of the parent genomes. D) The plant can dominate both original plants' habitats, driving them extinct.
FILL IN THE BLANK. Write the word or phrase that best completes each statement or answers the question. 49) Over long segments of chromosomes, the linear order of mouse and human genes is preserved. This is called conserved_________blank.
50) Two genes within an organism that arose from the duplication of a single gene in an ancestor are_________blank.
51) Genes that have DNA sequences similar to functional genes but that do not appear to produce any functional product are_________blank.
52) Many transposons found in the human genome may have been transferred from viruses to mammals via_________blank gene transfer.
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53)
The entire DNA sequence of a species is called its_________blank.
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Answer Key Test name: Chap 24_13e_Raven 1) [A, C, D]
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Clarify Question ● What is the key concept addressed by the question?● This question addresses gene duplication. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● Duplication of a single gene or a segment of a chromosome means to create a second copy. Gather Content ● What do you already know about gene duplication?● Duplication of a genomic region, either within a chromosome, or to another chromosome, allows genes with the same function to diverge because a “backup pair” of genes exist. ● A duplicated gene can lose function; it is not selected against because there is another functioning gene, not just an allele. ● The duplicated gene can also diverge and acquire new functions because the original persists. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Could a duplicated gene become an ortholog? No, because an ortholog is a copy of the same gene in another species, not within the same species. It could become a paralog though – a permanent copy of the gene. ● Could a duplicated gene become a centromere? No, because centromeres have special DNA sequences that allow them to be recognized as such. Choose Answer ● Given what you now know, what information and/or problem solving Version 1
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approach is most likely to produce the correct answer?● Could a duplicated gene lose function due to mutation? Yes. This is possible because the other copy of the gene is still carrying out the original function. In fact it is the most common outcome. ● Could a duplicated gene gain a new function due to mutation? Yes, this is also possible, again because the other copy of the gene is still carrying out the original function. ● Could a duplicated gene become a pseudogene? Yes. It could acquire a mutation that makes it nonfunctional, but still linger in the genome. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked what can occur to a duplicated gene. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that a duplicated gene can more freely mutate, and either lose or gain function, because the other copy of the gene can carry out the original function. ● Which two correct answers are really the same thing? 2) [B, C] 3) [A, C, D] 4) [A, B] 5) [A, B] 6) [A, C] 7) [A, B] 8) [A, B, D] 9) [A, B, C] 10) [C, D] Version 1
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Clarify Question ● What is the key concept addressed by the question?● This question addresses FOXP2. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. ● What key words does the question contain and what do they mean?● Neanderthals (Homo neanderthalensis) are an extinct close relative of humans. ● H. sapiens is the abbreviation for Homo sapiens – the modern human species. ● FOXP2 is a transcription factor gene that functions to develop centers for spoken language in the brain. Gather Content ● What do you already know about FOXP2?● FOXP2 is a transcription factor that controls the expression of other genes. ● It is expressed in the brain. ● The gene is found in other primates and mammals, but humans have a special version of the sequence that is thought to be essential for spoken language. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Can you conclude that Neanderthals evolved from H. sapiens? No, sharing a gene does not indicate that one species evolved from another. ● Can you conclude that H. sapiens evolved from Neanderthals? No, sharing a gene does not indicate that one species evolved from another. ● Can you conclude that verbal speech was impossible for Version 1
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Neanderthals? No, if anything the presence of the shared gene suggests the opposite. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Can you conclude that Neanderthals may have had the ability to use language? Yes, but emphasis on “may”. We know that FOXP2 seems to be essential for human spoken language, but we don’t know what other genes are necessary. ● Can you conclude that these two amino acid changes arose prior to the common ancestor of Neanderthals and H. sapiens? Yes, that is the most parismonious explanation for the shared sequence. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked what you can conclude from the fact that Neanderthals had the same “human” version of the gene FOXP2. ● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that the shared FOXP2 suggests that it arose before the common ancestor of humans and Neanderthals? ● Did you recognize that this gene suggests – but does not prove – that Neanderthals may have had language? 11) [A, B, C] 12) [A, B, D]
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Clarify Question ● What is the key concept addressed by the question?● This question addresses homology. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● Transcription factors are genes that regulate the transcription of other genes. ● Drosophila is the genus name for the fruit fly used in genetics research. Gather Content ● What do you already know about homology?● Homologous genes arose from one original gene. ● There are two kinds of homology: paralogy and orthology. ● Two genes within an organism that have arisen from the duplication of a single gene in an ancestor are called paralogs. ● In contrast, orthologs reflect the inheritance of a single gene from a common ancestor — a conserved gene. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Are the Hox genes an example of heterologues? No, that is not a term. They are examples of homologues – related genes. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The similar genes in different species are examples of orthologs. ● The similar genes in the same species are examples or paralogs. Version 1
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● The nonfunctional genes are examples of pseudogenes. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked what concepts are exemplified by Hox genes. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that Hox genes include orthologs – the same gene in different species? ● Did you recognize that Hox genes include paralogs – related genes in the same species? ● Did you recognize that Hox genes include pseudogenes – genes that have become nonfunctional? 13) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses homology. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● A common ancestor is an extinct species that gave rise to a set of modern species being compared. Gather Content ● What do you already know about homology?● Homologous genes arose from one original gene. ● There are two kinds of homology: paralogy and orthology. ● Two genes within an organism that have arisen from the duplication of a single gene in an ancestor are called paralogs. ● In contrast, orthologs reflect the inheritance of a single gene from a common ancestor — a conserved gene. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Would we call the BRCA1 genes paralogs? No, because each species only has one copy of the gene. ● Would we call the BRCA1 genes an example of polyploidy? No, because that refers to multiple copies of the genome in one species. ● Would we call the BRCA1 genes an example of synteny? No, because that refers to a set of multiple genes that retained their order on the chromosome during recombination. Choose Answer ● Given what you now know, what information and/or problem solving Version 1
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approach is most likely to produce the correct answer?● Would we call the BRCA1 genes orthologs? Yes, this is the correct term for genes in different species that are homologous – that is, that arose in a common ancestor. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked for the term to describe the same gene found in different species. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recall that two genes in different species that arose from common ancestry are called “orthologs”? 14) B 15) C 16) A 17) D 18) C 19) B 20) E 21) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses synteny. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about synteny?● Generally during evolution, chromosome rearrangements are common. ● Sometimes, however, the linear order of genes is the same in two species over long segments of chromosomes. ● This is called the conservation of synteny. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Do genes in the same order indicate aneuploidy? No, aneuploidy would mean an extra or missing chromosome. ● Do genes in the same order indicate the formation of pseudogenes? No, pseudogenes are genes with mutations that are no longer functional. ● Do genes in the same order indicate conservation of neoteny? No, neoteny is a term meaning that juvenile characteristics are maintained in an adult animal. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Do genes in the same order indicate conservation of synteny? Yes. The term synteny refers to a set of genes along a chromosome that are in the same order in two species. Reflect on Process Version 1
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● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked what is indicated by genes in the same order on the chromosomes of two species. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you remember that the conservation of gene order on a chromosome is called conservation of synteny? 22) D 23) C 24) B 25) A 26) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses pseudogenes. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● If a gene is no longer expressed, that means it is not transcribed and translated into protein. ● Transposons are small pieces of DNA that can hop into new locations. Gather Content ● What do you already know about pseudogenes?● Pseudogenes are inactive. ● They do not produce a functional product due to premature stop codons, missense mutations, or deletions. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Do we call inactive genes homologues, orthologs, or paralogs? No. These are all terms that describe the evolutionary relationship between a pair of genes. They do not indicate whether a gene is functional or not. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Is an inactive gene a pseudogene? Yes, that is the correct term for an inactive gene that remains in the genome. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked what term describes genes that have become nonfunctional due to mutations. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you remember that nonfunctional or nonexpressed genes in the genome are called pseudogenes? 27) B 28) D 29) A 30) C 31) A 32) C 33) A 34) C 35) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses gene expression patterns. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What keywords does the question contain and what do they mean?● Gene expression patterns are the patterns of where and when genes are expressed in the developing embryo or adult. ● Primates are the group of mammals that includes humans, other apes, monkeys, and lemurs. Gather Content ● What do you already know about gene expression patterns?● Gene expression refers to the amount of gene product produced at different times and places in the developing animal. ● Gene expression is the key to understanding why different organisms end up looking different. ● The best explanation for why a mouse develops into a mouse and not a human is that the same or similar genes are expressed at different times, in different tissues, and in different amounts and combinations. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Are the genes for the development of mammary glands, the lungs, or the heart likely to have different expression patterns in humans versus other primates? No, because these are not particularly different in humans than in other primates – certainly not as different as our brains are. Choose Answer ● Given what you now know, what information and/or problemVersion 1
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solving approach is most likely to produce the correct answer?● Are the genes for the development of the brain likely to have different expression patterns in humans versus other primates? Yes! Human brains are much larger for our size than the brains of other primates and have more complex capabilities. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which type of genes were most likely to be expressed differently in humans compared to other primates. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that genes for brain development were the most likely to have changed in humans? 36) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses non-protein-coding DNA. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● Pseudogenes are old genes that have become inactive, often due to a STOP codon. ● Non-protein-coding DNA is any DNA that does not lead to a protein product. Gather Content ● What do you already know about non-protein-coding DNA?● Nonprotein-coding DNA is responsible for much of the variation in genome size between different species. ● Non-protein-coding DNA was once called “junk DNA”, but scientists have begun to appreciate ways it may be functionally important. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Do the RNAs from non-protein-coding DNA suggest that pseudogenes code for proteins? No, this does not necessarily mean they produce proteins. ● Do the RNAs from non-protein-coding DNA suggest that non-proteincoding DNA has no function? No. In fact this suggests that it may have a regulatory function. ● Do the RNAs from non-protein-coding DNA suggest that pseudogenes have no function? No. Some pseudogenes may also have a previouslyunrecognized regulatory function. Choose Answer Version 1
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● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Do the RNAs from non-protein-coding DNA suggest that non-protein-coding DNA may regulate gene expression? Yes. If the RNAs regulate transcription of other genes, this may be an important regulatory function, maintaining the presence of the DNA. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked what is suggested by the fact that non-protein-coding DNA may produce RNAs that affect transcription. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that these regions may function to regulate the expression of other genes? 37) D 38) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses polyploidy. ● What type of thinking is required?● This question is asking you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. ● What key words does the question contain and what do they mean?● Plant species hybridize in nature – that is, two different species can mate to produce hybrid progeny. ● A polyploid species is a species that is stable and can reproduce, despite having a greater-than-diploid (2n) number of chromosomes. Gather Content ● What do you already know about polyploidy?● Polyploidy has occurred numerous times in the evolution of the flowering plants. ● Allopolyploids arise by hybridization of two lineages followed by genome duplication. ● Unless the hybrid genome is doubled, a hybrid plant will be sterile because it will lack homologous chromosomes that need to pair during metaphase I of meiosis. ● Because meiosis requires an even number of chromosome sets, only species with ploidy levels that are multiples of two can reproduce sexually. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Could a 3n hybrid form a new polyploid species? Unlikely, because at meiosis the 3 sets of chromosomes will not assort evenly, and gametes will be aneuploid. Version 1
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● Could a 5n hybrid form a new polyploid species? Unlikely, because at meiosis the 3 sets of chromosomes will not assort evenly, and gametes will be aneuploid. ● Could a CD hybrid form a new polyploid species? Unlikely, because at meiosis the two different sets of chromosomes (denoted by “C” and “D”) will not assort evenly, and gametes will be aneuploid. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Could a BBDD hybrid form a new polyploid species? Yes, because at meiosis the B chromosomes can pair together, and the D chromosomes can pair together, forming euploid BD gametes. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which hybrid would be most likely to become a new stable polyploid species. ● The question required you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. ● Did you recognize that a polyploid has to have a ploidy that is an even number, to have matched chromosomes for meiosis? 39) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses drug development. ● What type of thinking is required?● This question is asking you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. ● What key words does the question contain and what do they mean?● A target for drug development is a cellular component that the drug will interact with to prevent disease. ● Chagas disease, African sleeping sickness, and Leishmania are all human diseases caused by protozoans transmitted by insects. Gather Content ● What do you already know about drug development?● Genome sequences allow pharmaceutical researchers to find suitable drug targets to eliminate pathogens without harming the host. ● This can be especially important for protozoan diseases, since protozoans are more closely related to humans than bacteria. Consider Possibilities ● What other information is related to the question? Which information is most useful?● It is crucial that the drug target not be present in humans, or the drug would have bad side effects on the patient. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The ideal drug would be effective on all three pathogens, yet not interact with human genes. Version 1
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● So the drug should target genes that are shared by the organisms causing Chagas disease, African sleeping sickness, and Leishmania but not shared by humans. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked what would be the best targets for a new drug. ● The question required you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. ● Did you recognize that the drug should target the three pathogen genes, but not the human gene? 40) C 41) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses polyploidy. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. ● What key words does the question contain and what do they mean?● Meiosis is the process of sorting and dividing chromosomes for gamete formation. ● A hexaploid is an organism that has 6 sets of chromosomes; it is 6n. Gather Content ● What do you already know about polyploidy?● Polyploidy has occurred numerous times in the evolution of the flowering plants. ● Allopolyploids arise by hybridization of two lineages followed by genome duplication. ● Unless the hybrid genome is doubled, a hybrid plant will be sterile because it will lack homologous chromosomes that need to pair during metaphase I of meiosis. ● Because meiosis requires an even number of chromosome sets, only species with ploidy levels that are multiples of two can reproduce sexually. Consider Possibilities ● Consider the different answer options. Which can you rule out?● If a 6n species loses 1n, it becomes 5n. ● Would a 5n hybrid no longer be polyploid? No, it would still be polyploid as 5n > 2n. ● Would a 5n hybrid be able to reproduce with one of the parental species? No. With 5 sets of chromosomes, during meiosis they will be Version 1
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unable to assort properly and the gametes will be aneuploid. ● Would a 5n hybrid be able to reproduce only by self-fertilization? No. Even with itself, the aneuploid gametes would likely still be missing chromosomes, even in combination. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Will the 5n hybrid no longer be able to reproduce at all? Yes, most likely. With 5 sets of chromosomes, during meiosis they will be unable to assort properly and the gametes will be aneuploid. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked what would occur if a hexaploid species became 5n instead. ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that a 5n species cannot make viable gametes, because there is an odd number of chromosomes? 42) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses gene expression. ● What type of thinking is required?● This question is asking you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. ● What key words does the question contain and what do they mean?● Gene expression patterns refer to how a gene is transcribed: where (in the body), when (during development) and at what level. Gather Content ● What do you already know about gene expression patterns?● Gene expression refers to the amount of gene product produced in different times and places in the developing animal. ● Gene expression is the key to understanding why different organisms end up looking different. ● The best explanation for why a mouse develops into a mouse and not a human is that the same or similar genes are expressed at different times, in different tissues, and in different amounts and combinations. Consider Possibilities ● Consider the different answer options. Which can you rule out?● Is there likely to be a big difference in expression for genes regulating the digestive tract? Probably not since they have a similar diet– both petrels and penguins eat fish and other sea life. ● Is there likely to be a big difference in expression for genes regulating salt water tolerance? Not likely, since both live in the marine environment. ● Is there likely to be a big difference in expression for genes controlling Version 1
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organ development? No, there is no reason to think the organs are particularly specialized between the birds. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Is there likely to be a big difference in expression for genes controlling skeletal development? Yes. The wings, legs, and other bones of a penguin have become very different from the flying ancestor similar to a petrel. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked which type of genes were most likely to have different expression patterns in a penguin versus a petrel. ● The question required you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. ● Did you recognize that the skeleton is one of the most different features between a petrel and a penguin? 43) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses drug development. ● What type of thinking is required?● This question is asking you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. ● What key words does the question contain and what do they mean?● Crop sunflowers are sunflowers grown for their edible seeds. ● Fungal pathogens, such as downy mildew and Sclerotinia, are types of fungi that can cause disease. Gather Content ● What do you already know about drug development?● Genome sequences allow pharmaceutical researchers to find suitable drug targets to eliminate pathogens without harming the host. ● In the case of a new fungicide, the safety of the drug needs to be considered for both the plant (sunflowers) and the humans who will eat them. Consider Possibilities ● What other information is related to the question? Which information is most useful?● It is crucial that the target gene not be present in humans, or it could make people sick. ● It is also essential that the target gene not be present in sunflowers, or it could sicken the crop. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The ideal fungicide would be effective on downy mildew and Sclerotinia , yet not Version 1
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interact with human genes or sunflower genes. ● So the drug should target genes such as those encoding chitin proteins that are shared by downy mildew and Sclerotinia, but absent in sunflower and humans. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked what would be the best targets for a new fungicide. ● The question required you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. ● Did you recognize that the fungicide should target genes unique to fungi, and not those present in sunflowers or humans? 44) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses genome comparisons. ● What type of thinking is required?● This question is asking you to apply what you've learned to this specific example. ● What key words does the question contain and what do they mean?● Human genome -- the complete DNA of a human. ● Primates and apes -- Primates includes humans, other apes and monkeys. Apes are just humans and the other great apes. Gather Content ● What do you already know about genome comparisons?● The further apart the relationship you compare, the more changes you will see, from a longer stretch of evolutionary time. Consider Possibilities ● What other information is related to the question? Which information is most useful?● We need to compare close species to find genetic differences that would reveal changes unique to just humans. Otherwise we might find changes that happened earlier in the primate lineage. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Comparing humans and other apes is best to reveal only the changes that were recent and important for just human evolution. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked what genomes to compare to find human-specific differences. ● The question required you to apply what you've learned to this specific example. ● Did you recognize that you needed to compare the genomes of the closest relatives, not the distant ones? 45) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses genome comparisons. ● What type of thinking is required?● This question is asking you to apply what you've learned to this specific example. ● What key words does the question contain and what do they mean?● Human genome -- the complete DNA of a human. Gather Content ● What do you already know about genome comparisons?● The further apart the relationship you compare, the more changes you will see, from a longer stretch of evolutionary time. ● Even distantly related animals will share the genes that underlie basic metabolic functions in the cell. Those "housekeeping" genes have not changed very much. Consider Possibilities ● What other information is related to the question? Which information is most useful?● We know that compared to other mammals, humans have fewer functional olfactory receptors, They have reduced number of MHC genes. And they must have genes that promote larger brains. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Although MHC genes, olfactory receptors, and brain genes will all be different, it is less likely that cellular metabolism genes will have changed much. Reflect on Process Version 1
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● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked what genes were most likely to show human-specific differences. ● The question required you to apply what you've learned to this specific example. ● Did you recognize that genes would have changed for things that made humans special, but not for basic cellular functions? 46) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses genome size. ● What type of thinking is required?● This question is asking you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. ● What key words does the question contain and what do they mean?● Genome size -- the number of base pairs in the genome. ● Polyploidization -- when the whole genome is duplicated (often in plants). Gather Content ● What do you already know about genome size?● Genome size is affected by polyploidization. The process doubles the genome size, but then is typically followed by shrinking as duplicated genes are lost. ● Genome size is also affected by how much noncoding DNA, like transposons, are maintained in the genome. Some species seem to eliminate noncoding DNA, like the pufferfish. While other species seem to tolerate large amounts, like humans. ● Complex organisms often have bigger genomes -- but not always! Consider Possibilities ● What other information is related to the question? Which information is most useful?● Genome size is affected by BOTH ploidy and noncoding DNA. One or the other is more important in different organisms. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The most Version 1
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complete answer is: Genome size is affected both by polyploidization and also how much noncoding DNA is maintained over time. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked about what determines genome size in different organisms. ● The question required you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. ● Did you recognize that there are multiple factors, and that different factors are important for different organisms? Did you remember the different examples from the textbook? 47) B 48) A 49) synteny 50) paralogs 51) pseudogenes 52) horizontal 53) genome
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Chapter 25 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) Homo sapiens have existed on earth for about 10% of the earth's history. ⊚ true ⊚ false
2) Prokaryotes were the only living organisms present on earth for about 2 billion years. Multicellular eukaryotes have only been around for about 25% of earth's history ⊚ true ⊚ false
3) RNA was probably the first molecule used to encode genetic information; the use of DNA came later. This is due to RNA's inherent stability and its ability to store information more accurately than DNA. ⊚ ⊚
true false
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 4) The age of the Earth according to modern estimates is about A) 8 billion years. B) 4.6 billion years. C) 3.5 billion years. D) 1.5 billion years. E) a few thousand years.
5)
The oldest microfossils are of
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A) prokaryotes. B) eukaryotes. C) insects. D) pollen grains. E) small animals.
6)
Life apparently originated on Earth about A) 1 million years ago. B) 6000 years ago. C) 4.5 billion years ago. D) 8 billion years ago. E) 3.5 billion years ago.
7)
The early Earth's reducing atmosphere probably contained all of the following except A) carbon dioxide. B) water. C) oxygen. D) hydrogen sulfide. E) methane.
8) An experimental test of the hypothesis to explain the origin of the first organic compounds on Earth might include all of the following sequential steps, except for A) assembling an atmosphere with H2, CH4, NH3, and H2S. B) placing this atmosphere over liquid water. C) inoculating with a few bacteria to get the process started. D) increasing the temperature of the gases. E) providing energy with electrical spark discharges.
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9) Which of the following was produced in experiments on primitive Earth conditions conducted by Miller-Urey and others? A) ammonia and water B) amino acids C) CO2 and H2O D) ammonia and hydrogen sulfide E) methane and oxygen
10) All of the following were produced in experiments on primitive Earth conditions conducted by Miller-Urey and others, except for A) amino acids. B) organicmolecules. C) prokaryotes. D) hydrogen cyanide. E) urea.
11) It has been discovered that enzyme-like catalysis can be carried out not only by proteins but also by A) sugars. B) DNA. C) phospholipids. D) RNA. E) steroids.
12)
The oldest fossils of eukaryotes have been estimated to be
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A) 6000 years old. B) 8 billion years old. C) 4.5 billion years old. D) 1.5 billion years old. E) 1995 years old.
13) Imagine that NASA discovered a new planet with an atmosphere rich in hydrogen gas, hydrogen sulfide, ammonia and methane. We would call this a(n) A) reducing atmosphere, because of the availability of hydrogen atoms that can donate electrons. B) reducing atmosphere, because it would reduce the energy necessary to build molecules. C) oxidizing atmosphere, because of the availability of oxygen compounds. D) oxidizing atmosphere, because of the lack of oxygen gas.
14)
Which of the following was demonstrated by the Miller-Urey experiment? A) Life began in the oceans. B) Life can be started experimentally in the laboratory. C) Organic molecules could be formed from a set of simple chemicals. D) Life began on the prebiotic Earth 3.5 billion years ago.
15)
Eukaryotic cells acquired mitochondria and chloroplasts by A) endosymbiosis. B) exocytosis. C) pinocytosis. D) mutation. E) natural selection.
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16) Two principal organelles in eukaryotes that were apparently derived from different types of bacteria are the A) microfilaments and microtubules. B) mitochondria and chloroplasts. C) rough ER and smooth ER. D) plasma membrane and nuclear membrane.
17)
The group that probably gave rise to chloroplasts is the A) cyanobacteria. B) green photosynthetic bacteria. C) purple sulfur bacteria. D) nonsulfur purple bacteria. E) methane bacteria.
18)
True multicellularity is a major characteristic of A) all eukaryotes and a few prokaryotes. B) animals and plants only. C) eukaryotes only. D) protists, plants, and animals. E) prokaryotes and protists.
19)
A scientist is studying endosymbiosis in cells. This means she is investigating A) how mitochondria and chloroplasts were derived from eukaryotic cells. B) how mitochondria and chloroplasts were derived from prokaryotic cells. C) how mitochondria and chloroplasts evolved into eukaryotic cells. D) how mitochondria and chloroplasts evolved into prokaryotic cells.
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20) In the original experiments by Stanley Miller and Harold Urey to synthesize organic molecules in an abiotic environment, which one of the following would you NOT expect to find in the collection flask? A) urea B) amino acids C) ATP D) adenine E) formaldehyde
21) The apparatus in the figure was used by Stanley Miller and Harold Urey to study the origin of life on Earth. What compound was excluded from the apparatus so that it would form a reducing atmosphere?
A) CO2 B) O2 C) NH3 D) H2 E) H2O
22) Which one of the following statements about endosymbiosis and the origin of the eukaryotic cell is FALSE?
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A) Mitochondria are the descendants of a type of parasitic bacteria. B) The chloroplasts of red and green algae are the descendants of cyanobacteria. C) Algae incorporated prokaryotic cells that became chloroplasts, but never acquired mitochondria. D) Many compartments of the eukaryotic cell are derived from the endomembrane system. E) Both the chloroplast and the mitochondria of eukaryotes are descendants of prokaryotic cells.
23) Vascular plants appeared about 450 million year ago. Vascular plants have existed on earth for_________blank. A) 10% of itshistory B) 20% of itshistory C) 50% of itshistory D) 75% of itshistory E) 90% of itshistory
24)
Why is there free oxygen in the air? A) Organisms needoxygen to manufacture ATP. B) Free oxygen hasbeen present since the formation of the earth's atmosphere. C) Evaporation ofthe oceans liberated oxygen. D) It is aby-product of photosynthesis. E) Free oxygen hasseeped from cracks in the earth's crust.
25)
Why is a reducing atmosphere conducive to the origin of life? A) It is morefavorable for the development of organic molecules. B) It is rich infree oxygen. C) It is devoid oforganic molecules. D) It is verysimilar to today's atmosphere.
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26)
Which eon would contain rocks with no fossils? A) Archean B) Hadean C) Proterozoic D) Phanerozoic
27) A scientist is analyzing air bubbles trapped in ancient rocks that can be used to understand the ancient atmosphere. What do you expect the scientist will observe when comparing rocks younger than 3.8 billion years old to rocks older than 3.8 billion years? A) The ratio of the carbon-12 isotope will be lower in the younger rocks, because living organisms preferentially use carbon-12 over other isotopes. B) The younger rocks will have higher levels of carbon dioxide, because there was no carbon dioxide in the atmosphere before animals evolved and expelled it as waste. C) The ratio of carbon-12 will be lower in the older rocks, because carbon-12 had to build up on earth before life could evolve. D) The amount of carbon will vary unpredictably in the younger rocks, because rock weathering added carbon dioxide to the atmosphere, and volcanic activity sequestered it.
28)
Why is there uncertainty about the date when the earliest forms of cellular life originated?
A) There are fossils of cells, but the nuclei and mitochondria are hard to distinguish. B) The only evidence for organisms before 2.5 billion years is based on isotope analysis in rock. C) There is weaker evidence for fossils from the oldest dates, and stronger evidence for fossils from the younger dates. D) Many scientists argue that stromatolites are simply a mineral formation, and was never alive.
29) During the Snowball Earth events temperatures at the equator rarely exceeded -20 degrees Celsius. Why didn't heat from the sun melt the ice?
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A) The high levelsof atmospheric moisture created extensive cloud cover. B) Ice reflected most of radiant energy. C) The ozone layerabsorbed all the heat. D) The earth's corewas cooled and kept the ice frozen.
30) What would result for global climate from a massive drop in atmospheric carbon dioxide? A) A decrease in surface temperature B) An increase in ocean temperature C) Increased rock weathering D) Increased nitrogen availability E) A decrease in free oxygen content
31) Why have plants been implicated in the Ordovician and Devonian glaciations, but not the Proterozoic glaciations? A) Proterozoicplants used anoxygenic photosynthesis. B) Proterozoicplants had simple root structures that did not increase rock weathering. C) Land plants had not yet evolved during the Proterozoic. D) The nonvascular plants present during the Proterozoic did not contribute to global nutrient cycles.
32)
How did humans colonize the New World?
A) Early humans walked across a land bridge during periods of lowered sea level. B) Christopher Columbus and a host of other explorers were the first to colonize the Americas. C) Humans drifted across the Atlantic on primitive canoes. D) Humans were present during the break-up of Gondwana.
33)
What is the advantage of having cyanobacteria living inside a cell?
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A) Enhancedprotection of DNA B) Intracellularproduction of glucose C) Much moreefficient protein synthesis D) Allows the cell to manufacture ATP
34)
Infolding of the cellular membrane has led to the development of the A) chloroplast B) mitochondria C) nucleolus D) ribosome E) nuclear envelope
35)
How would the hydrolysis of phosphodiester bonds impede the origin of life? A) It would slow therate of protein synthesis. B) It would preventthe assembly of nucleic acids. C) It would stop the formation of cell membranes. D) It would digestamino acids.
36) Brown algae are thought to have acquired chloroplasts by engulfing red algae. If that is the case, how many engulfing and endosymbiosis events occurred to produce brown algae? A) Two -- one for chloroplasts in red algae, and one when brown algae engulfed red algae. B) Three -- one for mitochondria, one for chloroplasts in red algae, and one when brown algae engulfed red algae. C) Four -- one for the endoplasmic reticulum, one for mitochondria, one for chloroplasts in red algae, and one when brown algae engulfed red algae. D) About a dozen -- one for each type of membrane-bounded organelle, plus one for brown algae engulfing red algae.
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37) In the early millennia after the formation of the Earth, what was the most important way that geological events like weathering and volcanoes affected the ability of life to form? A) Smoke and dust blocked the sun, preventing light from reaching the surface. B) Lava and weathering prevented soil formation, and thus no plants could grow. C) Lava and rockfall would bury early organisms before they could evolve. D) They affected levels in the atmosphere, which led to extreme temperatures.
38)
How strong is the evidence of early Earth for living cells before 3.4 billion years ago?
A) The evidence is strong that there were NO living cells before 3.4 BYA because isotope analysis cannot find fixed carbon-12. B) The evidence is weak because there are only biomarker molecules found in rocks older than 3.4 BYA and no fossils of any kind. C) The evidence is still controversial, but there are both microfossils and isotope data suggesting the existence of cells from rocks older than 3.4 BYA. D) The evidence is indisputable because there are clearly detailed microfossils older than 3.4 billion years as well as isotope and biomarker data.
39) Would you expect the membranes of organelles, like the Golgi and the endoplasmic reticulum, to be more similar to the plasma membrane or to the mitochondrial membrane? A) More similar to mitochondria because, like mitochondria, they arose from an endosymbiotic event. B) The Golgi would be more similar to mitochondria because it arose from an endosymbiotic event, but the endoplasmic reticulum derived from the nuclear envelope. C) More similar to the plasma membrane, because they were derived from infoldings of the cell's membrane. D) They would actually be most similar to chloroplasts, because they derived from a similar ancestor.
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Answer Key Test name: Chap 25_13e_Raven 1) FALSE Humans have only existed for 0.2% of the Earth's history. 2) TRUE 3) FALSE 4) B 5) A 6) E 7) C 8) C 9) B 10) C 11) D 12) D 13) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the reducing atmosphere of the early earth. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about the reducing atmosphere of the early earth?● One view of the early atmosphere of the earth is that in addition to carbon dioxide, nitrogen gas, and water vapor, it also contained hydrogen gas, hydrogen sulfide, ammonia, and methane. ● We refer to such an atmosphere as a reducing atmosphere because of the ample availability of hydrogen atoms and their electrons. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● An atmosphere full of hydrogen is a reducing atmosphere, because hydrogen can donate electrons to other molecules – in chemical terms, it can reduce them. ● This reducing atmosphere also serves to lower the energy needed to create larger molecules. But this is not why it is called a reducing atmosphere. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. Version 1
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● Did you recognize that an atmosphere rich in hydrogen gas is a reducing atmosphere, because hydrogen can donate electrons, or “reduce”, other compounds? 14) C 15) A 16) B 17) A 18) C 19) B 20) C 21) B 22) C 23) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the age of the earth. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about the age of the earth?● The planet first formed and began to cool 4500 million years ago, or 4.5 billion years ago. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Since vascular plants are 450 million years old, they have only been around for 10% of the earth’s history. Surprising, isn’t it? ● Of course, multicellular life has been around for less than 1 billion years, so vascular plants have been present during much of the time that multicellular organisms have been. Reflect on Process● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you remember that the earth first formed 4500 MYA? ● Did you realize that that means vascular plants have only been around for 10% of the history of the planet? 24) D Version 1
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25) A 26) B 27) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses carbon in the atmosphere. ● What type of thinking is required?● This question is asking you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. Gather Content ● What do you already know about carbon in the atmosphere?● Will the younger rocks have higher levels of carbon dioxide, because there was no carbon dioxide in the atmosphere before animals evolved and expelled it as waste? No. The early atmosphere of the earth had high levels of carbon dioxide (but low levels of oxygen) ● Will the ratio of carbon-12 will be lower in the older rocks because carbon-12 had to build upon earth before life could evolve? No, carbon12 did not have to build up. ● Will the amount of carbon vary dramatically in the younger rocks, because rock weathering added carbon dioxide to the atmosphere, and volcanic activity sequestered it? No. This is backward – rock weathering sequesters carbon dioxide when it is subsequently combined with calcium, and volcanoes add carbon dioxide to the atmosphere. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Will the ratio of the carbon-12 isotope be lower in the younger rocks, because living organisms preferentially use carbon-12 over other isotopes? Yes. When life began, carbon-12 started becoming sequestered in living tissues and deposits from living things, so the ratio of carbon-12 in the atmosphere went down. This change is used by scientists as evidence for Version 1
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the time of the emergence of living things. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to weigh and judge, or evaluate, evidence to choose the best of the possible answers. ● Did you remember that living organisms preferentially use the carbon12 isotope? ● Did you realize that this “signature” of life can actually be seen in the carbon isotopes of different rock layers? 28) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the fossil evidence for the earliest forms of life. ● What type of thinking is required?● This question is asking you to apply what you have learned, to choose the best explanation for why the date of the earliest cells is controversial. Gather Content ● What do you already know about the origin of life?● The earliest cells were prokaryotes. ● They originated sometime between 3.8 BYA and 2.7 BYA, but the evidence for cells is strongest for the later dates. ● The main pieces of evidence are: ● 3.8 BYA: Isotope analysis (but no fossil cells), suggests that some living organism was fixing carbon. ● BYA: Tiny fossil cells look like prokaryotes, and isotope analysis supports carbon fixation, but little structural detail can be seen. ● BYA: Larger fossil cells have detailed structures, and are found in microbial mats from shallow seas. ● 2.7 BYA: Stromatolite fossils resemble more recent living organisms. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● The best summary is that there is weaker evidence for fossils from the oldest dates and stronger evidence for fossils from the younger dates. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result?● The question required you to remember what you learned about the different early fossil evidence, and consider the strength of each one. ● Did you remember the different pieces of evidence for these early fossils? ● Did you recognize that the evidence for the more recent fossils was the strongest? 29) B 30) A 31) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses glaciation. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about glaciation?● There is growing evidence that plants contributed to two glaciations. ● The initial colonization of land by plants was followed by gradual cooling and abrupt glaciation 488 to 444 mya in the Ordovician period. The early land plants lacked roots, but studies using extant relatives show they released organic acids that can increase rock weathering. ● The most convincing proposal is that phosphorous, an essential nutrient for plant growth, was released from the rocks through weathering and entered the ocean where it supported extensive algal growth. The rapid growth of the photosynthetic algae led to increased uptake of CO2 for photosyn-thesis, decreasing atmospheric CO2 levels and triggering glaciation. ● A second glaciation was concurrent with the diversification of vascular plants 400 to 360 mya during the Devonian period. Vascular plants’ extensive root systems increased weathering of rocks, which decreased atmospheric CO2 levels. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The Proterozoic Eon lasted from 2500 to about 500 mya. ● Multicellular plants originated shortly before the Cambrian period Version 1
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(~500 mya), and did not colonize land until the Ordovician period (~450 mya). ● Therefore, before the Ordovician there could not have been increased rock weathering due to plants, leading to glaciation. ● In short, the Proterozoic predates the evolution of land plants. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the Proterozoic is the older time period that predates the Cambrian? ● Did you recognize that the role of plants in glaciation involves rock weathering? 32) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses human migration. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about human migration?● During the last 2 million years, cold periods led to glaciation and a drop in sea level. As a result, a land bridge formed between Asia and North America. ● Humans and other animals migrated over the land bridge between the once disconnected continents. ● A connection between Australia and southeast Asia also allowed for migration. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Gondwana broke up about 150 mya, but modern humans evolved only about 200,000 years ago (0.2 mya). So humans arrived much later after Gondwana had already separated. ● Christopher Columbus sailed in 1492, but humans first arrived in the Americas much earlier, roughly around 15,000 years ago. ● Early humans did not have to use canoes or boats to reach the Americas – they were connected to Asia by a land bridge. Humans walked across this land bridge, which was much wider due to lower sea levels in the past. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the breakup of Gondwana was much earlier than the evolution of humans? ● Did you recognize that Christopher Columbus came much later than the earliest humans? 33) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses endosymbiosis. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about endosymbiosis?● Photosynthetic eukaryotic cells possess chloroplasts, the energy-harvesting organelles. ● Mitochondria and chloroplasts are both believed to have entered early eukaryotic cells by a process called endosymbiosis. ● Chloroplasts are derived from cyanobacteria. The red and green algae acquired their chloroplasts by directly incorporating a cyanobacterium. The brown algae most likely incorporated red algae to obtain chloroplasts Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Cyanobacteria are photosynthetic bacteria. In the process of endosymbiosis, a cell hosts cyanobacteria. The cyanobacteria benefit the cell by producing glucose via photosynthesis. ● Those intracellular cyanobacteria eventually become chloroplasts. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. Version 1
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● Did you recognize that intracellular cyanobacteria, the progenitors of chloroplasts, benefited cells by providing glucose from photosynthesis? 34) E 35) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the molecular basis of early life forms. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about the molecular basis of early lifeforms?● Early life-forms needed both information molecules and enzymes. RNA may have served both functions at once. ● Although most enzymes are proteins, RNA can catalyze reactions as well as store genetic information. ● According to the RNA world hypothesis, RNA, rather than DNA, was the first nucleic acid that permitted self-replication, an important step toward life. ● Later DNA, which is more stable than RNA, took over the information storage function. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Both RNA and DNA have a backbone made of a series of phosphodiester bonds. ● So hydrolysis – breaking – of the phosphodiester bonds would have interfered with the formation of strands of these nucleic acids. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The Version 1
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question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that phosophodiester bonds comprise the backbone of both DNA and RNA? 36) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the endosymbiotic origin of mitochondria and chloroplasts. ● What type of thinking is required?● This question is asking you to connect what you know about several symbiotic events and analyze how many would have occurred in this lineage. Gather Content ● What do you already know about endosymbiosis theory?● Both mitochondria and chloroplasts were derived from endosymbiotic events when prokarotic cells were engulfed by a larger cell. ● Brown algae arose when a cell engulfed a red alga that had already engulfed the proto-chloroplast. Since red algae are eukaryotes, they already had mitochondria from an earlier endosymbiotic event as well. ● The other organelles like the ER were not derived from an endosymbiotic event. The ER got its membrane from the cell's plasma membrane. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● The sequence of events leading to brown algae would have had three engulfments -- for the mitochondria, the chloroplast, and the red algae. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to remember the origins of the different organelles. Version 1
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● Did you remember mitochondria and chloroplasts were derived from endosymbiosis? ● Did you recognize that algae have both mitochondria and chloroplasts? 37) D Clarify Question ● What is the key concept addressed by the question?● This question addresses the impact of geological events at the beginning of Earth's history. ● What type of thinking is required?● This question is asking you to draw connections, and analyze the main impact of geological events on the possibility of life. Gather Content ● What do you already know about geological events at the beginning of Earth's history?● The Hadean was named after Hades because the early Earth climate was mostly incredibly hot. But there may have been occasional frozen Earth events too. ● Both the intense heat and cold were incompatible with the formation of early life. ● High levels contributed to the intense heat, and changing the extreme temperature changes. ● Both weathering and volcano eruptions affected levels.
levels were the main driver of
Choose Answer ● Given what you now know, what information and/or problem-solving approach is most likely to produce the correct answer?● Since weathering and volcanism affected , which drove temperature changes, then the main way that they affected life was in the contributions to levels and temperature extremes. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to understand the connections between geology and levels, between and temperature, and also understand that early Earth temperatures were incompatible with life. ● Did you remember how geology affected ? How does affect temperature? ● Did you recognize how extreme temperatures were during the Hadean?
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38) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the evidence for the earliest cells on Earth. ● What type of thinking is required?● This question is asking you to evaluate the strength of the evidence for life arising before 3.4 BYA. Gather Content ● What do you already know about the evidence for the first cells?● The earliest cells were prokaryotes. ● They originated sometime between 3.8 BYA and 2.7 BYA, but the evidence for cells is strongest for the later dates. ● The main pieces of evidence are:● 3.8 BYA: Isotope analysis (but no fossil cells), suggests that some living organism was fixing carbon. ● 3.5 BYA: Tiny fossil cells look like prokaryotes, and isotope analysis supports carbon fixation, but little structural detail can be seen. ● 3.2 BYA: Larger fossil cells have detailed structures, and are found in microbial mats from shallow seas. ● 2.7 BYA: Stromatolite fossils resemble more recent living organisms. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Since there are both microfossils and isotope data from 3.5 and 3.8 BYA, the best answer is "The evidence is still controversial but there are both microfossils and isotope data suggesting the existence of cells from rocks older than 3.4 BYA." ● The evidence cannot be said to be "indisputable" because the microfossils at this age are not structurally detailed and obvious and the biomarker data is from younger rocks. Version 1
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to remember what you learned about evidence for early life, and weigh and judge the strength of this evidence. ● Did you remember the different types of evidence and their ages? ● Did you recognize that some of this evidence is still considered controversial? 39) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the endomembrane system and endosymbiosis. ● What type of thinking is required?● This question is asking you to analyze the question using what you learned to dissect the different answer options and choose the best one. Gather Content ● What do you already know about the endomembrane system and endosymbiosis?● The Golgi and the endoplasmic reticulum are part of the eukaryotic endomembrane system. ● Endosymbiotic events are thought to be responsible for the origin of mitochondria and chloroplasts. ● However, the endomembrane organelles are thought to have derived their membranes from the infolding of the main cell's plasma membrane. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Since the Golgi and ER were not derived from endosymbiotic events, the best answer is: "More similar to the plasma membrane because they were derived from infoldings of the cell's membrane." Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to remember what you learned about both the endomembrane system and endosymbiosis, and combine it with an analysis of the specific question and answer options. Version 1
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● Did you remember that the Golgi and ER are thought to have been derived from infoldings of the plasma membrane? ● Did you understand the difference between the endomembrane system and endosymbiosis?
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Chapter 26 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) Viruses are self-replicating but the replication is much faster in a host cell. ⊚ ⊚
2)
true false
Retroviruses are unique because they are a combination of RNA and DNA. ⊚ ⊚
true false
3) Nucleotide analogs are a class of drugs that are highly effective against many types of viruses. They work by halting the replication of viral genes. They are equally effective at stopping the spread of prion diseases. ⊚ ⊚
true false
4) Tetracycline is effective against viruses because it disrupts the action of the viral ribosomes. ⊚ ⊚
true false
5) The pneumonia caused by the influenza virus results from the accumulation of fluid and cell debris in the lungs. This occurs during the lysogenic life cycle of the virus. ⊚ ⊚
true false
CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 6) Which are correct statements about Human Papilloma Virus (HPV) and cancer? (Choose all that apply.)
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A) A vaccine against HPV can reduce the risk of cancer. B) About 70% of cervical cancers are caused by HPV. C) The HPV protein E7 binds the cell's Rb protein, allowing unregulated cell division. D) Viral infections cause cancer because they boost the energy stores of the cell. E) Cell proliferation is an adaptive response of the host to any viral infection, to outgrow the virus. F) HPV causes cancer by increasing apoptosis.
7) Check all of the correct statements regarding the use of metagenomics to describe viral diversity. A) Most samples are obtained from animals and plants. B) During sample collection, the actual virus needs to be isolated for analysis. C) Metagenomics has identified thousands of new viral species. D) Sample DNA is amplified using PCR.
8) The Baltimore system classifies viruses differently than traditional nomenclature. What correctly describes this system? (Check all that apply.) A) It only works for disease-causing viruses. B) It works for any virus, whether it infects humans or not. C) It breaks viruses down into 24 separate categories. D) It groups viruses with similar genomes. E) It distinguishes between viruses with + or - strand RNA.
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 9) A mutation in the gene encoding the integrase enzyme renders the protein non-functional. How would this affect-the HIV infection cycle?
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A) The gp120 glycoprotein would not be able to bind the CCR5 receptor. B) Reverse transcription would not be possible. C) The viral DNA would not be able to integrate the viral genome into a chromosome. D) Cutting and assembling the capsid would be halted.
10) Vibrio cholerae lives in water and gets toxin genes from a virus by phage conversion. The toxin kills the intestinal epithelial cells in the human host, resulting in massive diarrhea. Untreated cholera has about a 50% mortality rate. How do the bacteria benefit? A) Diarrhea helps the bacteria to spread from person to person. B) Killing humans provides nutrients for the bacteria. C) They don’t -- humans are not the main host and their symptoms are maladaptive for the bacteria. D) The bacteria reproduce faster in a dead human.
11) Once a prophage is present in a bacterial genome, viral genes are reproduced every time the bacterium multiplies. Expression of viral genes, however, is inhibited by a repressor protein. Cell stress can induce the formation of proteases that degrade the repressor. What will result? A) The virus will enter the lysogenic cycle. B) The bacterium will reject the viral genes. C) The virus will enter the lytic cycle. D) The bacterial genome will be denatured.
12)
What best describes whether a virus is likely to infect a particular cell? A) Viruses infect the first cells they encounter. B) If a host cell is weakened, viruses are likely to infect it. C) A virus will only infect host cells with the correct surface receptors. D) Viruses only attack epithelial cells, such as the cells lining the lungs. E) The initial choice is random but once a cell type is chosen it becomes the preferred
host.
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13) An experimental chemical has been shown to selectively cleave phosphodiester bonds. How would this affect a virus? A) Fragment thegenome B) Digest thecapsid C) Dissociate theenvelope D) Alter the hostbinding site E) Hydrolyze the protein coating
14)
Can a virus be killed? A) Yes, destroying its genome kills it. B) No, viruses are capable of self-assembly and cannot be permanently killed. C) Yes, separating the genes from the capsid kills it. D) No, viruses are nonliving and cannot die.
15) What kind of pathogen would retain its ability to cause infections after being treated with powerful proteolytic chemicals that would destroy all proteinaceous material? A) A virus B) A prion C) A fungus D) A bacterium E) A viroid
16) A doctor’s office has run out of the latest flu vaccine, but many patients are asking for it. One of the nurses finds some vials from last year’s batch in a refrigerator. Should they be used? A) Yes, because the preservatives and refrigeration ensure that the vaccine is still fresh. B) No, because each year the technology to make a good vaccine improves. C) No, because each year the vaccine is made against different subtypes of the flu virus. D) Maybe – the vaccine should be mixed in a test tube with the virus to see if it still inactivates it.
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17) Which class of drugs would be effective against HIV but not against most other pathogenic viruses? A) Nucleotide analogs that halt replication. B) Receptor antagonists that block viral entry. C) Non-nucleoside reverse transcriptase inhibitors that block reverse transcription. D) Translation inhibitors that stop assembly of viral proteins.
18) Gardasil is marketed as a cervical cancer vaccine, but it is actually a human papilloma virus (HPV) vaccine. Why is this done? A) The virusmultiplies more rapidly in cancerous cells. B) Cancer cells are particularly susceptible to viral infection. C) Genital warts is a sign of cancer. D) HPV in the cervical epithelial cells may cause the cells to become cancerous.
19) If the gp120 glycoprotein were damaged as a result of a mutation, HIV would have difficulty: A) binding to a host cell. B) leaving a macrophage. C) inserting its genes into the host cell's genome. D) assembling the capsid. E) attaching its RNA to a host cell's ribosome.
20)
Integrase inhibitors work by: A) Agglutinating thereverse transcriptase inhibitors B) Degrading the viralenvelope C) Preventing theincorporation of the viral DNA into the genome D) Blocking the finalviral assembly
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21) Plasma from a sick mouse is filtered across a membrane that has a 200 nm pore size. If the filtrate is still infectious when injected into a healthy mouse, then the pathogen is most likely a(n): A) bacterium B) archaean C) fungus D) virus E) parasitic worm
22)
Most viruses form a capsid around their nucleic acid core. This capsid is composed of A) proteins. B) monosaccharides. C) glycoproteins. D) lipoproteins.
23) In the late 20th century, a class of infectious proteins with no associated nucleic acids were identified. They are referred to as A) bacteriophages. B) latent viruses. C) viroids. D) prions. E) virions.
24) The HIV virus is considered a(n) ________ virus, because after getting integrated into the host cell chromosomes, it does not begin replicating immediately.
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A) phage B) latent C) transforming D) benign E) inducible
25) Each HIV particle possesses a_________blank on its surface, called gp120, that precisely binds to a protein, called CD4, that is found on the surfaces of the immune system cells called macrophages and T cells. A) nucleic acid B) phospholipid C) polysaccharide D) glycolipid E) glycoprotein
26)
Viruses are characterized by all of the following, EXCEPT A) being found in every organism investigated so far. B) being specific to the hosts they infect. C) being capable of independent reproduction. D) being acellular.
27)
All of the following are diseases caused by viruses EXCEPT A) strep throat. B) AIDS. C) polio. D) smallpox. E) measles.
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28)
Phages are viruses that can infect A) humans. B) plants. C) insects. D) farm animals. E) bacteria.
29) A layer of lipids, proteins and glycoproteins that covers the outer surface of some viruses is the A) capsid. B) casing. C) envelope. D) membrane. E) viroid.
30)
Viruses that become established as stable parts of the host cell genome are called A) lethal. B) potent. C) temperate. D) virulent.
31)
Prions are A) strands of nucleic acids encased in a protein coat. B) viral nucleic acids integrated into the host chromosomes. C) viral-infected cells. D) infectious proteins with no associated nucleic acid. E) proteins coded by pseudogenes.
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32) Which of the following is a virus with an icosahedral head, a collar and "whiskers", a long tail, tail fibers, and a base plate? A) influenza B) SARS-CoV-2 C) T4bacteriophage D) HIV E) poliovirus
33)
Benign Vibrio cholerae becomes pathogenic by all of the following steps except A) a bacteriophage introduces a gene coding for the cholera toxin. B) the cholera toxin gene is incorporated into the benign Vibrio cholerae chromosome. C) the benign host is transformed into a disease-causing agent by the toxin. D) the cholera toxin gene is translated. E) a bacteriophage binds only to benign Vibrio cholerae without pili.
34)
The infection cycle of HIV includes all of the following steps except A) attachment. B) entry. C) replication. D) immediately killing the host cell. E) viral DNA integrates into the host chromosome.
35)
The onset of AIDS is often accompanied by
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A) a steep drop in T cell numbers. B) macrophage infection. C) a positive HIV test. D) lung infections and other opportunistic infections. E) Kaposi's sarcoma.
36) An example of an "emerging virus" (a virus in a new host) with a lethality rate in excess of 50% is A) influenza virus. B) Ebola virus. C) hepatitis B. D) variola virus. E) yellow fever.
37)
HIV infects cells by recognizing the cell-surface markers with its own A) DNA. B) glycoproteins. C) reverse transcriptase. D) capsid protein. E) enzymes.
38)
Mad cow disease is caused by a A) bacterium. B) virus. C) viroid. D) virion. E) prion.
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39)
Nearly all viruses are constructed of A) DNA with a protein wrapping, called a capsid. B) RNA with a protein wrapping, called a capsid. C) either DNA or RNA with a protein wrapping, called a capsid. D) either DNA or RNA, however many do not have the capsid.
40) A scientist is studying the lysogenic cycle of the lambda phage of Escherichia coli. This means that she is investigating A) the integration of the phage DNA into a host cell's genome. B) the way that new phage particles are replicated and packaged into their capsids. C) the lysis of the bacterial cell. D) the mutation and evolution of virus genomes that compete for binding sites.
41)
If a virus enters the lytic phase in a host's cell, it will cause the host cell to A) reject thevirus. B) shrink because ofthe loss of cytoplasm that has been used in the synthesis of viral
DNA. C) lyse due to the action of enzymes. D) replicate itselfat a higher than normal frequency. E) initiate an attackon the virus.
42) Scientists have demonstrated that the cholera bacteria, Vibrio cholerae, can exist as a rather harmless form or as a disease-causing form? What causes the switch? A) A phage deletes and replaces the cholera bacterium genome. B) A phage introduces a toxin gene into the bacterium's chromosome. C) A prion causes the cholera protein to misfold. D) A viroid causes the bacterium to expand its host range to humans.
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43)
The specific white blood cells that HIV attaches to are the_________blank cells. A) CD4+ B) gp120-T C) CCR5-T D) CXCR4-T E) CD8-T
44) Diseases such as scrapie in sheep, "mad cow" disease in cattle, and Creutzfeldt-Jakob disease in humans are known as A) viroids. B) viruses. C) retroviruses. D) TSEs (transmissible spongiform encephalopathies). E) emerging viruses, for example Ebola.
45) Viruses infect every organism that has been investigated for their presence. However, viruses can only replicate in A) one host species each. B) vertebrates. C) the respiratory system. D) the extracellular space. E) certain cell types of their specific hosts.
46)
The switch from a lysogenic prophage to a lytic cycle is called
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A) transformation. B) induction. C) latency. D) phageconversion. E) injection.
47)
All of the following are part of phage conversion except A) injection of phage gene into host. B) transcription and translation of phage gene. C) induction of phage. D) expression of phage gene by host. E) integration of phage gene to form a prophage.
48) What is the name for parasitic viral DNA that has been integrated into the chromosome of its bacterial host? A) prophage B) prophase C) viroid D) virion E) arbovirus
49)
One way in which retroviruses differ from all other types of viruses is that retroviruses A) possess an RNA genome. B) possess only single-stranded nucleic acids. C) can create a prophage. D) have single-strained RNA that serves as viral mRNA. E) have the enzyme reverse transcriptase.
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50) The enormous genetic diversity of HIV has made it especially difficult to create a vaccine against the virus. We can attribute this genetic diversity to A) mutation hotspots in the hemagglutinin (HA) gene. B) mutation hotspots in the CD4+ molecule. C) the high error rate of reverse transcriptase. D) the high sensitivity of the virus to UV radiation.
51)
The direction of genetic information transfer in a retrovirus (such as HIV) is A) DNA to mRNA to protein. B) RNA to DNA to mRNA to protein. C) DNA to protein. D) RNA to mRNA to protein. E) RNA to protein.
52)
Which of the following statements about bacteriophage is NOT correct?
A) Bacteriophages do not have a viral envelope. B) A temperate phage can have its DNA integrated into the host chromosome as a prophage. C) Ultraviolet radiation can cause induction. D) A prophage is replicated with the bacterial chromosome and passed to the two new daughter cells. E) Late genes areonly expressed during the lysogenic cycle.
53)
Which of the following is a unique feature of viruses that separates them from bacteria? A) They are generally much smaller. B) They are often highly toxic. C) They lack proteins. D) They have different nucleotides in their hereditary material. E) They cannot exist outside of a host cell.
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54) While they are simple relative to cells, viruses often have a very diverse collection of components. Which one of the following choices is LEAST likely to be found as part of a virus? A) proteins with functional binding sites B) membrane components C) single-stranded DNA D) ribosomes E) glycoproteins
55) Which of the following would NOT be a component of a newly produced HIV virus particle? A) protein capsid B) RNA C) reverse transcriptase D) viral envelope E) complementary DNA
56) If a researcher developed a drug that prevented insertion of the SARS-CoV-2 spike protein into the endoplasmic reticulum, what effect would you predict from this drug? A) No effect, because the virus does not have organelles like the endoplasmic reticulum. B) It would make it easier for the virus to invade human cells. C) It would not affect the reproduction of the virus, because all the key information is carried in the RNA genome. D) The viral particles produced could not infect new cells. E) It would allow viruses to infect new cells, but they would do less damage.
57) Which of the following statements about the types and subtypes of the influenza (flu) virus is NOT true?
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A) The seasonal flu is caused by a Type A influenza virus. B) The strain is determined by the specific HA and NA proteins in the envelope of the virus. C) Antigenic shift occurs when coinfection of strains allows them to recombine into a new form. D) High mutation rates create antigenic drift, and require fresh vaccines each year. E) Genetic recombination between influenza and other families of viruses is common.
58)
Which of the following statements about emerging viruses is NOT true?
A) Emerging viruses are able to "jump" from one species to another. B) Ebola is an emerging virus that can have a mortality rate over 50%. C) The emerging virus SARS-CoV-2 is a coronavirus. D) Once they are officially recognized, emerging viruses are easy to treat and eradicate with existing drugs.
59) Which of the following statements about TSEs (transmissible spongiform encephalopathies) is NOT true? A) TSEs include scrapie in sheep, mad cow disease, chronic wasting disease in deer and elk, and kuru and variant Creutzfeldt-Jakob disease in humans. B) The incidence ofCreutzfeldt-Jakob disease in humans increased after an outbreak of mad cowdisease in England, suggesting that mad cow disease may be transmitted tohumans. C) Viroids are the likely cause of TSEs. D) TSEs do not seem to be affected by treatments that would eliminate nucleic acidbased diseases. E) Infectious TSE preparations do not seem to contain DNA or RNA.
FILL IN THE BLANK. Write the word or phrase that best completes each statement or answers the question. 60) Viruses are_________blank -coated fragments of DNA or RNA.
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61)
A_________blank can contain DNA or RNA as its genetic material, but not both.
62) Outside the protein sheath, many viruses have a(n)_________blank made of protein, lipid, and carbohydrate.
63) Viruses can_________blank only after they have entered a host cell, and only by using the host's cellular machinery.
64)
_________blank infects the CD4+ T cells, which are required for normal immunity.
65) MERS-CoV, SARS-CoV, and SARS-CoV-2 are members of the family of viruses called_________blank .
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Answer Key Test name: Chap 26_13e_Raven 1) FALSE 2) FALSE 3) FALSE
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Clarify Question ● What is the key concept addressed by the question?● This question addresses prions. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about prions?● A prion is a “proteinaceous infectious particle. ● Prions occur because certain proteins can sometimes misfold, and then catalyze other proteins to do the same, with misfolding spreading like a chain reaction. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● A nucleotide analog drug would inhibit viral genome replication because it can substitute into the spot of a nucleotide, and break the nucleic acid chain. ● However, prions do not have a nucleic acid genome. They are just made of protein. Therefore, such a drug would not affect them. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. Version 1
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● Did you recognize that prions lack a nucleic acid genome, and they are simply made of protein? 4) FALSE 5) FALSE 6) [A, B, C]
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the link between viruses and cancer. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about the link between viruses and cancer?● Some viruses can cause cancer. Hepatitis B can cause liver cancer, and some strains of human papilloma viruses can infect the cervix and cause cervical carcinoma. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Do viral infections cause cancer because they boost the energy stores of the cell? No, they are harmful to cells and tend to waste their energy. ● Is cell proliferation an adaptive response of the host to any viral infection, to outgrow the virus? No, only certain viruses tend to cause cancer. ● Does HPV causes cancer by increasing apoptosis? No, the opposite. It prevents apoptosis, and prevents cell death. ● Does the HPV protein E7 bind the cell's Rb protein, allowing unregulated cell division? Yes, this is the beginning of tumorigenesis from HPV. ● Are about 70% of cervical cancers caused by HPV? Yes, this is correct. ● Is there a vaccine against HPV that can reduce the risk of cancer? Yes, Version 1
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this is correct. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that a viral protein can directly interfere with cell cycle regulators like Rb? ● Did you realize that HPV causes cancer? ● Did you know that there is a vaccine against HPV? 7) [C, D] 8) [B, D, E] 9) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the HIV infection cycle. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about the HIV infection cycle?● The HIV infection cycle has multiple steps, using several viral-encoded enzymes. ● The gp120 protein binds to the CD4 receptor and then the CCR5 receptor, to dock and fuse into the cell. ● Reverse transcriptase creates a double-stranded DNA copy of the viral RNA genome. ● Integrase allows the viral DNA to merge into a host cell chromosome. ● The genome is transcribed, translated, processed by proteases and then new viruses are assembled and released. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● If integrase was mutated, would the gp120 glycoprotein be unable to bind the CCR5 receptor? No, gp120 can interact with CCR5 directly after undergoing a conformational change. ● If integrase was mutated, would reverse transcription be impossible? No, that is the job of reverse transcriptase. ● If integrase was mutated, would cutting and assembling the capsid be halted? No, that is the job of protease. ● If integrase was mutated, would the viral DNA be unable to incorporate into the host cell chromosome? Yes. Integrase is necessary to integrate the viral DNA into the host cell chromosome. Version 1
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the integrase enzyme is necessary to integrate the viral DNA into the host cell genome? 10) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cholera. ● What type of thinking is required?● This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. Gather Content ● What do you already know about cholera?● Cholera is a devastating disease caused by the bacterium Vibrio cholerae. ● The bacterium usually exists in a harmless form, but a second, disease-causing form also occurs. ● A lysogenic phage introduces into the host bacterial cell a gene that codes for the cholera toxin. ● The toxin gene is expressed along with the other host genes, thereby converting the benign bacterium to a disease-causing agent. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● Does killing humans provide nutrients for the bacteria, or do they reproduce faster in a dead human? No, they require a living host. ● Are the symptoms of cholera maladaptive for the bacteria? No. As a waterborne disease, the diarrhea is essential for the bacteria and virus to spread from host to host. ● Does diarrhea help the bacteria to spread from person to person? Yes. The symptom is adaptive for the bacteria to help them spread.
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. ● Did you recognize that diarrhea is adaptive for the bacteria and virus, because it spreads them to a new host 11) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses phage induction. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content ● What do you already know about phage induction?● In a lysogen, expression of the prophage genome is repressed by a viral regulatory protein. ● If the cell is stressed, the prophage can be derepressed, expressing the enzymes necessary for excision of the genome, and the lytic cycle can commence. ● The switch from a lysogenic prophage to a lytic cycle is called induction because it requires turning on the gene expression necessary for the lytic cycle. ● It can be stimulated in the laboratory by stressors such as starvation or ultraviolet radiation. ● The molecular basis of induction is a stress-induced protease that can destroy the repressor protein that keeps the prophage silent. The normal function of this protease is to degrade a host repressor that controls DNA repair genes. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● When cell stress degrades the repressor, will the bacterial genome be denatured? Version 1
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No, it shouldn’t affect the bacterial genome. (If anything, the protease will induce DNA repair.) ● When cell stress degrades the repressor, will the bacterium reject the viral genes? No, this isn’t a mechanism to do that. ● When cell stress degrades the repressor, will the virus enter the lysogenic cycle? No, it was already in the lysogenic cycle. Instead, it will express viral genes and enter the lytic cycle Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that when the repressor is degraded, then viral genes are expressed and the prophage can excise and enter the lytic cycle? 12) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses viral host range. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about viral host range?● Viruses occur as obligate intracellular parasites in every kind of organism that has been investigated for their presence. ● Viruses infect fungal cells, bacterial cells, and protists as well as cells of plants and animals; however, each type of virus can replicate in only a very limited number of cell types. A virus that infects bacteria would be ill-equipped to infect a human or plant cell. ● The suitable cells for a particular virus are collectively referred to as its host range. ● The first step of infection is called attachment, in which the virus contacts and becomes specifically bound to the cell. This step limits the host range of the virus as they bind to specific proteins on the surface of the cell. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Because of the need to bind receptors on the cell to enter, a virus will only infect host cells with the correct surface receptors. Reflect on Process Version 1
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● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that a virus has to match the receptors on its specific host cell? 13) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses viral structure. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about viral structure?● A virus will contain a genome made of DNA or RNA. ● The genome will lie within a capsid made of protein. ● It may have an envelope made of lipid membrane with proteins. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Would cleaving phosphodiester bonds digest the capsid? No, because that is formed of protein, and phosphodiester bonds are not found in proteins. ● Would cleaving phosphodiester bonds dissociate the envelope? No, because that is formed of protein and lipids, and phosphodiester bonds are not found in proteins or most lipids. ● Would cleaving phosphodiester bonds alter the host binding site? No, because that is likely a protein, and phosphodiester bonds are not found in proteins. ● Would cleaving phosphodiester bonds hydrolyze the protein coating? No, because phosphodiester bonds are not found in proteins. ● Would cleaving phosphodiester bonds fragment the genome? Yes, because viral genomes are made of either DNA or RNA, which contain phosphodiester bonds. Version 1
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that phosphodiester bonds are found only in DNA and RNA – thus they are found in the viral genome? 14) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses whether viruses are alive. ● What type of thinking is required?● This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. Gather Content ● What do you already know about viruses as organisms?● Viruses are genetic elements enclosed in protein; they are not considered organisms because they lack many of the features associated with life, including cellular structure, and independent metabolism or replication. ● For this reason viral particles are not called viral cells, but virions, and they are generally not described as living or dead but as active or inactive. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● You cannot kill a virus, because they are nonliving entities. If they are never really alive, they can never die. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to weigh and judge evidence, or evaluate, to Version 1
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choose the best of the possible answers. ● Did you recognize that viruses cannot be killed, since they are not truly alive? 15) E Clarify Question ● What is the key concept addressed by the question?● This question addresses viroids. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about viroids?● Viroids are tiny, naked molecules of circular RNA, only a few hundred nucleotides long, that are important infectious disease agents in plants. ● In other words, viroids are infectious RNAs with no protein. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Since viroids are just RNA without protein, they are the only infectious agents that would persist after the destruction of proteins. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you realize that viroids are made of just RNA?
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16) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the flu virus. ● What type of thinking is required?● This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. Gather Content ● What do you already know about the flu virus?● Unlike most other viruses, the influenza virus is known for high rates of mutation and recombination. ● Different strains of flu virus, called subtypes, differ in their protein spikes. One of these proteins, hemagglutinin (H), aids the virus in gaining access to the cell interior. The other, neuraminidase (N), helps the daughter viruses break free of the host cell after replication. ● Parts of the H molecule contain “hotspots” with a high rate of mutation. ● Also, viral RNA segments are readily reassorted by genetic recombination when two different subtypes simultaneously infect the same cell. This may put together novel combinations of H and N spikes unrecognizable by human antibodies specific for the old configuration. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Does the technology to make a good vaccine improve each year? Not really. ● Should the vaccine be mixed in a test tube with the virus to see if it still inactivates it? No. Remember that the vaccine is a mimic of the Version 1
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virus that trains the immune system to recognize it. It does not directly inactivate the virus. ● Will the preservatives and refrigeration ensure that the vaccine is still fresh? Yes, probably – but it will likely be ineffective. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. ● Did you recognize that the flu vaccine is different every year, to match the common new subtypes? 17) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses HIV replication. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about HIV replication?● Human immunodeficiency virus (HIV), the agent that causes acquired immunodeficiency syndrome (AIDS), is a retrovirus. ● Retroviruses have an RNA genome that is reverse-transcribed into DNA by the enzyme reverse transcriptase. The DNA fragments produced by reverse transcription are often integrated into a host’s chromosomal DNA. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Would most viruses be affected by nucleotide analogs that halt replication? Yes, because all viruses use nucleotides in their RNA or DNA genome. ● Would most viruses be affected by receptor antagonists that block viral entry? Yes, because viruses often take advantage of cell receptors to enter the cell. ● Would most viruses be affected by translation inhibitors that stop assembly of viral proteins? Yes, because all viruses (although not viroids) use proteins in their capsid. ● Would most viruses be affected by non-nucleoside reverse transcriptase inhibitors that block reverse transcription? No. Most Version 1
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viruses don’t use reverse transcriptase. Only retroviruses like HIV use reverse transcriptase, so it would be affected but mist other viruses would not be. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that unlike most viruses, HIV relies on a reverse transcriptase enzyme? 18) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the link between viruses and cancer. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about the link between viruses and cancer?● Some viruses can cause cancer. Hepatitis B can cause liver cancer, and some strains of human papillomaviruses can infect the cervix and cause cervical carcinoma. ● Sometimes viral proteins interfere with the regulation of oncogene expression. Or, the integration of a viral genome into a host chromosome may disrupt a gene required to control the cell cycle. Finally, some viruses actually encode oncogenes. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● HPV, the human papilloma virus, can cause cervical cancer. ● By getting a vaccine that prevents infection by HPV, the patient can avoid this risk factor and lower their risk of cervical cancer. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The Version 1
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question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the HPV vaccine can lower the risk of cancer because HPV infection can cause cervical cancer? 19) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses HIV infection. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about HIV infection?● HIV infects key immune-system cells: macrophages and T cells. ● The viral glycoprotein gp120 precisely fits on the cell-surface marker protein CD4+ on those cells. When HIV attaches to two receptors CD4+ and CCR5, it is able to pull itself across the cell membrane and enter the cell. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The gp120 glycoprotein binds to the CD4+ protein on the surface of macrophages and T cells, allowing the HIV virus to enter the cell. ● So if it was mutated, it would not be able to bind to the host cell, and that would prevent viral entry. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this Version 1
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unfamiliar situation. ● Did you recognize that the gp120 glycoprotein binds to the CD4+ cellsurface marker protein on macrophages and T cells, allowing viral entry? 20) C 21) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses virus size. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about virus size?● A traditional definition of viruses was that they were “filterable agents.” That is, infectious agents that could pass through a 500 nm filter. ● Some viruses, like Mimivirus or Pandoravirus, can be larger. However, anything smaller than 200 nm is likely to be a virus. ● The smallest bacterium, Mycoplasma, is between 200-300 nm across. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Viruses are the smallest of the options listed. Bacteria, archaea, a fungus or worm would all be caught in the filter. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that viruses are smaller than bacteria, archaea, Version 1
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fungi, or worms? 22) A 23) D 24) B 25) E 26) C 27) A 28) E 29) C 30) C 31) D 32) C 33) E 34) D 35) A 36) B 37) B 38) E 39) C 40) A 41) C 42) B 43) A 44) D 45) E 46) B 47) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses phage conversion. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about phage conversion?● Phage conversion refers to the conversion of a bacterium into a more dangerous form. ● This occurs when the bacterium is infected with a phage that carries a disease gene. ● For instance, a lysogenic phage that infects V. cholerae introduces a gene that codes for the cholera toxin. This gene, along with the rest of the phage genome, becomes incorporated into the bacterial chromosome. The toxin gene is expressed by the bacterium, converting it into a disease-causing agent. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Since the important part of phage conversion is the insertion of the toxin gene into the host chromosome, all the steps of phage infection and integration must take place ● However, induction of the phage is not important. It is the inactive, prophage sitting in the chromosome that has “converted” the cell – not the activity of the phage virus itself. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that in phage conversion, the bacterium is converted to a more dangerous form by the insertion of a toxic phage gene into the genome? 48) A 49) E 50) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses HIV infection. ● What type of thinking is required?● This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. Gather Content ● What do you already know about HIV infection?● HIV is a retrovirus, so the RNA genome is copied into DNA, then back into RNA again. ● Inside the host cell, the HIV particle sheds its protective coat. Reverse transcriptase synthesizes a double strand of DNA complementary to the virus RNA, often making mistakes and introducing new mutations. ● This double-stranded DNA then enters the nucleus and is incorporated into the host cell’s DNA. After a period of dormancy, the HIV provirus directs the host cell’s machinery to produce many copies of the virus. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Does HIV acquire mutations due to mutation hotspots in the hemagglutinin (H) molecule? No, that is a feature of the influenza virus, not HIV. ● Does HIV acquire mutations due to mutation hotspots in the CD4+ molecule? No, the CD4+ molecule is part of the human cells, not the HIV virus. ● Does HIV acquire mutations due to the high sensitivity of the virus to UV radiation? No, this is not a feature of HIV. ● Does HIV acquire mutations due to the high error rate of reverse transcriptase? Yes! This is the best explanation. As a retrovirus, the HIV Version 1
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genome is copied by reverse transcriptase, which has a high error rate. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. ● Did you recognize that HIV is a retrovirus, and thus relies on reverse transcriptase to copy its genome from RNA to DNA? 51) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the HIV infection cycle. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about the HIV infection cycle?● HIV is a retrovirus, so the RNA genome is copied into DNA, then back into RNA again. ● Inside the host cell, the HIV particle sheds its protective coat. Reverse transcriptase synthesizes a double strand of DNA complementary to the virus RNA, often making mistakes and introducing new mutations. ● This double-stranded DNA then enters the nucleus and is incorporated into the host cell’s DNA. After a period of dormancy, the HIV provirus directs the host cell’s machinery to produce many copies of the virus. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● HIV is a retrovirus. The particles carry RNA, which is reverse transcribed into DNA, then later transcribed into mRNA and translated into protein. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that retroviruses carry RNA in their particles, Version 1
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which are reverse transcribed into DNA, then later transcribed and translated? 52) E 53) A 54) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses virus structure. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about virus structure?● All viruses have a core of nucleic acid surrounded by protein. This structure lacks cytoplasm, and it is not a cell. ● Viruses contain a genome of either DNA or RNA, which may be linear or circular; single-stranded or double-stranded. ● Many animal viruses have an envelope around the capsid that is rich in proteins, lipids, and glycoproteins. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Viruses may contain a genome of single-stranded DNA. ● They have a capsid with proteins that have functional binding sites for the host cells. ● They may also have membrane components in an envelope, including glycoproteins. ● However, viruses do not carry ribosomes. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that viruses often include all of the components listed, except for ribosomes? Viruses cannot support their own translation – they rely on the host cell for that. 55) E
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Clarify Question ● What is the key concept addressed by the question?● This question addresses HIV. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about HIV?● HIV is a retrovirus with an RNA genome. The RNA is reverse transcribed into DNA, then after a latent period it is transcribed back into RNA. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The HIV viral particle consists of an RNA genome inside a protein capsid, also containing reverse transcriptase, all within a viral envelope. ● However, the HIV viral particle does not contain complementary DNA. The DNA copy of the genome is only present within the host cell during the latent period. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that as a retrovirus HIV has an RNA genome, not a Version 1
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DNA genome? 56) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses SARS-CoV-2. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about SARS-SoV-2?● SARS-CoV-2 uses its spike proteins in the envelope to bind to ACE2 receptors in the host cell. ● When new virus particles are made, the spike protein is produced and inserted into the ER membrane. Then the viral genome and nucleocapsid become enveloped in part of the ERGIC membrane, and they bud out of the cell. This puts the spike protein into the virus envelope. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Since the spike protein is necessary for infecting new cells, and it gets into the viral envelope by inserting into the ER, then if that insertion fails any resulting viruses would not be able to infect new cells. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize the spike protein has to be inserted into the ER membrane to eventually make it into the virus envelope? Version 1
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● Did you realize that the spike protein is essential for binding receptors and infecting new cells? 57) E 58) D 59) C 60) protein 61) virus 62) envelope 63) reproduce 64) HIV 65) coronavirus
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Chapter 27 13e CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 1) Check all of the mutually beneficial relationships between prokaryotes and eukaryotes. A) Prokaryotes aid in digestion in ruminants. B) The human microbiome aids in human health. C) Nitrogen-fixing bacteria live in plant root nodules. D) Agrobacterium tumefaciens bacteria form galls in some plants.
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 2) Current classification of prokaryotes is based on A) morphology of flagella. B) sequencing of proteins, DNA, and RNA. C) occurrence of transverse binary fission. D) type of colony formation. E) ability to stain the cell wall with Gram stain.
3) Early classification systems of the bacteria employed all of the following characteristics except A) the ability to photosynthesize. B) rRNA sequences. C) motility. D) colony or filament forming. E) spore formation
4) An oil spill occurs, and a member of the clean up team suggests adding fertilizer. What might this accomplish?
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A) The fertilizer encourages the growth of microbes that can break down the oil. B) The chemicals in the fertilizer digest the oil residues. C) The fertilizer interacts with the oil droplets and renders them harmless. D) The fertilizer volatilizes the oil.
5) Vibrio cholerae produces a toxin that destroys the intestinal epithelium. This leads to massive diarrhea which can kill the human host. Why might this trait have been selected for? A) Diarrhea helps the host by flushing out the bacteria. B) The bacteria require a dead host. C) The diarrhea spreads the bacteria to new hosts. D) It wasn't; diarrhea is a nonspecific outcome of most infections.
6) Farmers often practice crop rotation to help enrich agricultural fields. Why are beans and other legumes often used in the rotations? A) Bean genomes encode nitrogenase withnif genes. B) Bacteria in legume root nodules fix nitrogen. C) Legumes enrich the soil by forming endospores. D) Legumes remove toxins from the soil. E) Less carbon dioxide.
7) Phil has chronic ulcers, he has been taking acid blockers and drinking vast amounts of liquid antacids. These help relieve the symptoms but he still suffers from ulcers. What would be the best course of action to treat the source of his ulcers? A) Taking several different antacids B) Increasing the dosage of acid blockers C) Taking a course of antibiotics D) Reducing the stress in his daily life E) Changing his diet to include more fiber
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8)
Why is chlamydia much more common than syphilis? A) Chlamydia is spread via droplet inhalation. B) Syphilis can penetrate a condom whereas chlamydia cannot. C) Many chlamydia infections are asymptomatic. D) Chlamydia is viral, and viral diseases spread much quicker. E) Chlamydia is resistant to most antibiotics.
9)
Why are children often told that if they eat too much candy their teeth will fall out?
A) Sugar attacks tooth enamel. B) Sugars gradually replace the tooth enamel. C) Bacteria use the sugar to make ATP. This fermentation process produces acids as a by-product. D) Bacteria secrete acids in order to digest the sugar molecules.
10) Amanda is a microbiologist who studies a pathogenic, chemoorganoheterotrophic bacterium. In what ways are they (Amanda and the bacteria) similar? A) Both have cell walls. B) Both have linear chromosomes. C) Both have mitochondria for ATP production. D) Both are capable of sexual reproduction. E) Both obtain carbon from consuming organic molecules.
11) Genes abc and def have a high average cotransduction frequency. Genes abc and xyz have a very low average cotransduction frequency. What is the best explanation for this difference?
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A) The genes abc and def are much closer to each other on the chromosome. B) The genes abc and def must share a higher degree of sequence similarity. C) Both genes have a high affinity for the viral binding sites. D) Both genes code for gene products that are necessary for viral replication.
12)
Are transformation and transduction the same process? A) Yes; they both involve the acquisition of viral genes. B) No; only transformation passes on genes for pathogenicity. C) Yes; both processes transfer specific gene products to a specific bacterium. D) No; although both involve gene transfer the sources of the genetic material differ.
13) The cell walls of a newly-discovered bacterium contain high concentrations of phospholipids, along with proteins and lipopolysaccharide. If the bacteria are Gram stained, what color would you expect as a result? A) Purple B) Pink C) Blue D) Clear, it does notretain any stain
14) Many cells of the immune system have receptors that detect peptidoglycans and lipopolysaccharides. How do pathogenic bacteria avoid detection? A) Pathogenic bacteria lack cell walls. B) Pathogens often encase themselves in a gelatinous capsule. C) Peptidoglycans are absent from pathogenic bacteria. D) Disease is only possible if the immune system has been compromised by some other event.
15) A researcher observed a reduction in the number of chromosomes during cell division for a microbe, he concludes that the microbe must be
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A) Eukaryotic B) Prokaryotic C) Archaea D) A virus
16) DNA replication and gene expression machinery in archaea more closely resemble eukaryotic cells than the same processes in bacteria. However both bacteria and archaea are prokaryotic. What does this suggest? A) Eukaryotic cells are descended from modern archaea. B) Bacteria are not related to archaea. C) Eukaryotes shared a more recent common ancestor with archaea than with bacteria. D) There must have been two origin events, one producing the bacteria and the other producing archaea and eukaryotes.
17)
If the label on a slide reads Gram-positive bacillus, what would a students expect to see? A) Pink helicalcells B) Purple rod shapedcells C) Red sphericalcells D) Blue coiledcells
18) A high concentration of chlorophyll-like pigment molecules embedded in the folded plasma membrane would suggest those bacteria are A) Chemolithoautotrophic B) Chemolithoheterotrophic C) Photoautotrophic D) Chemoorganoheterotrophic
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19) A microbiologist suspects a strain of Staphylococcus aureus is resistant to methicillin. What would be the best approach to test this suspicion? A) Perform a Gram stain. B) Sequence the chromosome looking for resistance genes. C) Calculate the doubling time for the bacteria. D) Inject the bacteria into a host animal and look for disease symptoms. E) Add methicillin to the growth plates.
20) When some bacteria are exposed to nutrient-poor conditions, they form thick-walled structures that contain the chromosome and a small amount of cytoplasm. These structures are called A) plasmids. B) pseudomonads. C) nucleoids. D) endospores. E) exospores.
21)
Prokaryotes undergo a process that produces cells that are identical. This process is called A) mitosis. B) meiosis. C) conjugation. D) binary fission. E) syngamy.
22)
The prokaryotic DNA is located in the
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A) capsid region. B) nucleoid region. C) endospore region. D) peptidoglycan region. E) pili region.
23) Prokaryotes are very important ecologically because of their involvement in all of the following, EXCEPT A) photosynthesis by autotrophs. B) nitrogen fixation in soil. C) diseases like smallpox, measles, or rabies. D) denitrification of nitrate. E) bioremediation to clean up the environment.
24)
In all of the following characteristics, prokaryotes differ from eukaryotes except in A) cell size. B) multicellularity. C) chromosomes. D) nucleic acids as the hereditary material. E) organelles.
25)
Which of the following is not a shape seen in prokaryotes? A) Spheres B) Rods C) Spirals D) Icosahedrons
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26) Prokaryotic cell walls consist of a network of polysaccharide molecules connected by cross-bridges of A) other polysaccharides. B) lipids. C) peptides. D) ribosomes. E) chromosomal DNA.
27) Certain prokaryotes can withstand drying and hotter temperatures because of their ability to form A) cell walls. B) endospores. C) flagella. D) organelles. E) plasmids.
28)
In some types of bacteria, a layer called the capsule outside the cell wall plays a role in A) maintaining the shape of the cell. B) dividing the cell wall during binary fission. C) ability to cause disease. D) transporting nutrients into the cell.
29)
Bacterial ribosomes differ from eukaryotic ribosomes in all of the following except A) they act as sites of protein synthesis. B) they are smaller than in eukaryotes. C) tetracycline and chloramphenicol can bind to bacterial ribosomes. D) they differ in ribosomal proteins. E) they differ in RNA content.
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30)
Archaea differ from Bacteria in all of the following EXCEPT A) cell wall composition. B) plasma membrane make up. C) DNA replication. D) gene expression. E) the presence of a nucleoid region.
31)
Prokaryotes that harvest both energy and carbon atoms from organic molecules are called A) photoautotrophs. B) chemolithoautotrophs. C) photoheterotrophs. D) chemoheterotrophs. E) nitrogen fixers.
32) Some prokaryotes attach to other substrates by hairlike outgrowths, which are shorter than flagella. These are called A) endospores. B) flagellin. C) pili. D) plasmids. E) fission products.
33)
Bacteria cause all of the following human diseases except A) cholera. B) diphtheria. C) tuberculosis. D) tetanus. E) malaria.
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34) A researcher finds that the bacteria from dental plaque are relatively easy to kill when grown at high dilution on a petri dish. So what makes them so hard to kill and remove on people's teeth? A) On teeth they are fed a wider variety of nutrients. B) On teeth they form a complex, resistant biofilm. C) There is no difference since the bacteria species is the same. D) The temperatures are different in someone's mouth. E) On teeth they form endospores.
35)
Bacterial sexually transmitted diseases include all of the following except A) gonorrhea. B) syphilis. C) chlamydia. D) herpes.
36)
Gonorrhea and syphilis are most commonly controlled by A) abstinence. B) antibiotics. C) boiling water. D) fluoride treatment. E) pasteurization.
37) The enzymes for cellular respiration in eukaryotic organisms are located within the mitochondria. In prokaryotic organisms, these enzymes are attached to infolded regions of the
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A) cell wall. B) cellmembrane. C) ribosomes. D) circular DNA. E) nuclear membrane.
38) A microbiologist explains to one of her biology classes that her research focuses on the nucleoid region of the cholera bacteria. This means that she is studying a region within the bacterium that contains the A) nucleic acids. B) nuclear membrane. C) R plasmids. D) peptidoglycan.
39) Prokaryotes reproduce rapidly and this allows helpful genetic variation to spread quickly through a population. Which process does NOT provide new, potentially helpful DNA to a bacterium? A) transduction B) transformation C) mutation D) binary fission E) conjugation
40) Tuberculosis remains a serious worldwide health problem due to all of the following factors, except one. Which is incorrect?
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A) There are strains with multi-drug resistance (MDR). B) It grows slowly and evades the immune system. C) It has an unusual cell wall and resists many antibiotics. D) It is easily spread through the air. E) Everyone infected has obvious symptoms.
41) A microbiologist is conducting a research project on chemolithoautotrophs. This means that the investigator is examining certain aspects of a bacterium that A) can oxidize inorganic molecules such as ammonia and sulfur for energy. B) is a purple nonsulfur bacteria which depends on light. C) obtains carbon from organic molecules. D) can use the energy from sunlight to build organic molecules from carbon dioxide. E) uses light as its energy source and carbon for organic compounds.
42) If left untreated, syphilis infections go through four stages. The first stage is a sore called a chancre. The signs of the second stage are A) some nerve damage, loss of some teeth, and perhaps a dimming of color vision. B) very few, with many victims having no symptoms. C) rash, sorethroat, and sores in the mouth D) persistence of the chancre and bleeding at the chancre site. E) a yellowish-white discharge from the urethra.
43) Which of the following statements about Hfr cells and bacterial conjugation is NOT correct?
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A) An Hfr cell becomes an F- cell if its integrated F plasmid is excised. B) If excision of the F plasmid from an Hfr cell includes some bacterial genes, a partial diploid can result. C) The genes that are transferred from an Hfr cell into a recipient cell during conjugation replace the equivalent genes in the recipient cell. D) An F' plasmid contains some bacterial genes. E) Cells with integrated F' plasmid have two copies of some genes.
44) The data below shows recombination of genes (1-5) according to the amount of time available for transfer of the bacterial chromosome during conjugation between different genetic strains in E coli. Based on these data, which gene is closest to gene 1? (Note: The entire chromosome is transferred in 100 minutes.)
A) gene 2 B) gene 3 C) gene 4 D) gene 5
45)
Plasmids are distinguished from bacterial chromosomes in that
A) plasmids are circular, bacterial chromosomes are linear. B) plasmids occur in the cytoplasm, bacterial chromosomes occur in the nucleus. C) plasmids are composed of RNA, bacterial chromosomes are composed of DNA. D) plasmids have few genes, bacterial chromosomes have many genes. E) plasmids consist of single-stranded nucleic acids, bacterial chromosomes consist of double-stranded nucleic acids.
46)
Which of the following statements about generalized transduction is false?
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A) "Head full"packaging always places only phage DNA into the phage head during phagepackaging in generalized transduction. B) Generalized transduction always involves lytic phage. C) Generalized transduction can be used to map bacterial genes. D) Genes that are close together on the bacterial chromosome will have a relatively large cotransduction frequency. E) Homologous recombination can integrate the transferred DNA during generalized transduction.
47) Which of the following events is LEAST likely to result in a genetic change in a particular bacterial cell? A) forming a pilus B) conjugation C) mutation D) transduction E) transformation
48) Various techniques have been developed to isolate strains of bacteria carrying a particular mutation. One of them is, bacteria containing wild-type cells and cells of a desired mutant are grown on a medium lacking the nutrient for which the desired mutants are auxotrophic but containing an antibiotic that only kills growing cells. In this environment, A) both wild-type and mutant cells are killed. B) both wild-type and mutant cells survive. C) wild-type cells survive; mutant cells die. D) wild-type cells die; mutant cells survive. E) only double mutants survive.
49)
Which of the following statements about transformation is NOT correct?
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A) The bacterium E.coli is incapable of natural transformation. B) Transformation requires a special kind of pilus. C) Artificialtransformation is essential to many recombinant DNA techniques. D) All R-plasmidscontain antibiotic-resistance genes. E) Natural transformation of the Enterobacteriaceae is a significant public health risk.
50)
Which of the following statements about tuberculosis (TB) is false? A) MDR TB is more expensive to treat. B) Not completing a full course of antibiotic can select for MDR strains. C) HIV and TB can be transmitted in the same manner. D) The spread of TB can be very rapid. E) The reservoir of TB is humans and no vector is required for transmission.
51)
Which of the following statements about sexually transmitted diseases (STDs) is false?
A) Gonorrhea, syphilis, and chlamydia are all transmitted through sexual contact. B) Because chlamydia has both bacterial and viral characteristics, it cannot be treated with antibiotics. C) Chlamydia is known as the "silent STD." D) The incidence of chlamydia has increased as gonorrhea has decreased. E) Syphilis can be transmitted from a mother to her fetus.
52) The purple and green nonsulfur bacteria have an unusual nutritional strategy. The source of energy is light, however organic carbon is used as a source of carbon and of electrons. They are thus classified as A) chemolithoautotrophs. B) chemoorganoheterotrophs. C) photolithoautotrophs. D) photoorganoheterotrophs. E) pathogens.
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FILL IN THE BLANK. Write the word or phrase that best completes each statement or answers the question. 53) Prokaryotes split into two lines early in the history of life. The differences are so fundamental that they are assigned to two different domains, the_________blank and the Bacteria.
54) Cell walls of bacteria (domain Bacteria) usually consist of_________blank, a network of polysaccharide molecules connected by polypeptide cross-links.
55) Members of the genus _________blank are associated with scarlet fever, rheumatic fever, pneumonia, necrotizing fasciitis (“flesh-eating disease”), sore throat, and dental cavities.
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Answer Key Test name: Chap 27_13e_Raven 1) [A, B, C] 2) B 3) B 4) A 5) C
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Clarify Question ● What is the key concept addressed by the question?● The question focuses on why Vibrio cholera evolved to cause diarrhea. ● What type of thinking is required?● This question is an “apply” question, so it is asking for you to take a concept you already know (relationships prokaryotes have with eukaryotes) and apply it to a new scenario to solve the problem. Gather Content ● What do you already know about cholera? How does it relate to the question?● Cholera is a disease that has killed large numbers of people; the diarrhea is extreme. ● Cholera is notorious for spreading quickly through a population, especially if the water supply becomes contaminated. ● What other information is related to the question? Which information is most useful?● Fitness for pathogens relates strongly to spreading into new hosts. Killing the host is not beneficial though. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● The bacteria that induced diarrhea were likely more successful and selected because they spread to many more hosts. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to suggest why Vibrio cholera benefited from diarrhea. Version 1
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● Did you recognize that the bacteria were selected upon for this trait, not humans? ● Did you realize that diarrhea helps the bacteria spread? 6) B
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Clarify Question • What is the key concept addressed by the question? o For generations, farmers have used legumes in crop rotations because they improve the soil, making later crops more productive. How do legumes improve the soil? • What type of thinking is required? o This is an “evaluate” question, so use your knowledge about nutrient cycling to evaluate the relative merit of each hypothesis. Remember, a hypothesis is an educated guess, so you should be able to back up your choice with facts. Gather Content • What do you already know about nutrient cycling? How does it relate to the question? o There are three nutrients crucial for plant growth: nitrogen, phosphorous, and potassium. Plants also need a lot of organic material, such as decomposing leaves, to make the soil fluffy and allow air and water to pass through it. Growing legumes improves which of these four essential soil characteristics? • What other information is related to the question? Which information is most useful? o Most plants and animals cannot use nitrogen gas. Nitrogen gas consists of two nitrogen atoms bound together with three covalent bonds. This makes the molecule very difficult to break apart. Only organisms with nif genes are able to break apart nitrogen gas and turn it into nitrate or ammonia, compounds plants and animals can use. These organisms are called nitrifiers. o In oceans and lakes, most nitrogen fixation is done by cyanobacteria. These bacterial colonies form specialized cells called heterocysts, where Version 1
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nitrogen fixation takes place. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o After reviewing the background information, cover up the options and try to answer the question as if it were a short answer question. Now, compare your answer to the options. Are you able to cross some out that are clearly incorrect? How many do you have left? o After crossing out the ones you know are incorrect, compare the options you have left. What do you know about legumes such as beans and peas? How can that help you answer the question? Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to explain how legumes improve the soil. You had to compare the five hypotheses and pick the best one. o If you got the correct answer, well done! o If you got an incorrect answer, where did the process break down? • Were you able to cross off “Less carbon dioxide”? Carbon dioxide isn’t important for soil nutrients. More important aspects are nitrogen, phosphorous, potassium, and organic matter. • Did you get stuck between “Bean genomes encode nitrogenase with nif genes” and “Bacteria in legume root nodules are nitrifiers”? Plants do not have the nif genes. Only bacteria and archaea are able to fix nitrogen. Legumes seem to fix nitrogen because they form a symbiosis with nitrogen-fixing bacteria in their roots. Version 1
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7) C
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Clarify Question • What is the key concept addressed by the question? o You are Phil’s doctor. You have been treating his ulcers with acid blockers (such as omeprazole) and liquid antacids, but these treatments don’t seem to be solving the underlying problem. What should you do to get the ulcers to go away? • What type of thinking is required? o This question is an “apply” question, so it is asking you to use the information you already know about ulcers and apply it to this new situation. Gather Content • What do you already know about ulcers? How does it relate to the question? o Doctors used to think that ulcers were caused by stress or eating acidic foods. One researcher proposed that peptic ulcers were caused by a bacterial infection. He was completely ignored until, during a presentation at a conference, he drank a solution of the bacterium Heliobacter pylori, which gave him peptic ulcers. • What other information is related to the question? Which information is most useful? o Which treatments has Phil taken so far? Why haven’t they worked? Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Given that Phil’s ulcers may be caused by Heliobacter pylori, what would you propose as his next treatment? Reflect on Process Version 1
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to figure out which treatment option would be most likely to treat the source of Phil’s ulcers. o If you got the correct answer, great job! o If you got an incorrect answer, where did you get stuck? • Phil has already been taking anacids and acid blockers. These treated his symptoms, but not the source of the problem. It is probably time to try something new. • Heliobacter pylori is a bacterium, which could be killed using antibiotics. If Phil’s ulcers are due to an infection, antibiotics would kill the bacteria and stop the ulcers. 8) C
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Clarify Question • What is the key concept addressed by the question? o You observe that there are far more cases of chlamydia than of syphilis. Which hypothesis best explains this phenomenon? • What type of thinking is required? o This question is an “analyze” question, so it is asking you to merge your knowledge of two different groups (chlamydia and syphilis) to find similarities and differences. Which of the differences best explains the observed phenomenon? Gather Content • What do you already know about chlamydia? How does it relate to the question? o The bacterium Chlamydia trachomatis is an STD, meaning that it infects a new host when they have sex with an infected person. Women in the early stages of infection generally do not show any symptoms, even though they can transmit the disease. Late-stage symptoms include pelvic inflammatory disease, sterility, and heart disease. Untreated, chlamydia can cause death. It can be treated using antibiotics such as tetracycline. • What other information is related to the question? Which information is most useful? o Syphilis is caused by the bacterium Treponema pallidum. It is an STD and can be transmitted through sexual intercourse. It can also be transmitted vertically from a mother to her fetus or horizontally by coming in contact with an open syphilis sore. Symptoms include a rash, open sores, a sore throat, heart disease, nerve damage, mental disease, and blindness. In the third stage of the disease, symptoms disappear for a while and the host is no longer infectious. Version 1
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Make a Venn Diagram for syphilis and chlamydia. How are they similar? How are they different? o Which of their differences best explains why chlamydia is so much more common than syphilis? Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question asked you to pick the best hypothesis that explains why chlamydia is so much more common than syphilis. o If you got the correct answer, great job! o If you got an incorrect answer, where did you get stuck? • Both diseases have an asymptomatic stage, but syphilis patients are not contagious during this stage. Women with early-stage chlamydia can be asymptomatic but still be contagious. 9) C
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Clarify Question • What is the key concept addressed by the question? o Eating too much candy can cause you to get dental cavities. Why? • What type of thinking is required? o This question is an “evaluate” question. You need to determine which hypothesis is the best explanation of the phenomenon you have observed. Gather Content • What do you already know sugars? How does it relate to the question? o Sugars are simple carbohydrates. Many sugars linked together form more complex carbohydrates such as starch or cellulose. • What other information is related to the question? Which information is most useful? o The dental plaque you brush off your teeth each night is made of biofilm, which is made of many different bacterial species. Some of these bacteria perform aerobic respiration, while others produce anaerobic respiration. What are the by-products of aerobic and anaerobic respiration? Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Cover up the options and try to answer the question as if it were a short answer question. Now, uncover the options. Do any of the options match your answer? o What else do you know about sugars? What else do you know about bacteria? Version 1
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o Once you’ve narrowed down your options, pick the one with the most support. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to explain why eating sugars results in tooth decay. o If you got the correct answer, great job! o If you got an incorrect answer, where did you get stuck? • Sugars themselves do not attack the tooth enamel. Bacteria using anaerobic respiration to consume the sugars produce lactic acid, which breaks down the enamel. Would bacteria using aerobic respiration break down your enamel? 10) E
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Clarify Question • What is the key concept addressed by the question? o How are bacteria and eukaryotes (specifically, humans) similar? • What type of thinking is required? o This question is an “apply” question, so it is asking for you to find similarities and differences between two different concepts (bacteria and eukaryotes) that you learned about individually. Gather Content • What do you already know about eukaryotes and prokaryotes? How does it relate to the question? o Humans are a group of eukaryotes. In general, eukaryotes have linear chromosomes made of DNA. Do bacteria have chromosomes? Are they linear or circular? o Mitochondria are organelles that produce the molecule ATP. ATP can be broken apart to release energy anywhere it is needed in the cell. Do eukaryotes have mitochondria? Do bacteria? o Sexual reproduction involves the production of gametes (cells that contain half the copies of chromosomes of the normal cells). Two gametes fuse to form a zygote, which has half of its DNA from one parent and half of its DNA from another parent. Conjugation is similar to sexual reproduction, but is not true sexual reproduction. Which organisms do sexual reproduction? Which organisms use meiosis to produce gametes? o Cell walls are rigid structures outside of the plasma membrane. They help protect the cell and keep the cell from exploding in hypotonic solutions. Cell walls can be made of many things, including cellulose, lignin, silica, and peptidoglycan. Do bacteria have cell walls? Do humans have cell walls? o Organisms can get nutrients a variety of ways, including heterotrophy Version 1
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and autotrophy. Heterotrophs get energy and raw materials by consuming other organisms. Autotrophs produce their own energy. For example, plants use the sunlight to make energy and get their carbon from carbon dioxide. They do not need to consume other organisms to get these things. How do humans get energy and raw materials? How do chemoorganoheterotrophic bacteria do these things? Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Make a Venn diagram showing how eukaryotes and bacteria are similar and different. You should end up with some grey areas. For example, some eukaryotes and some bacteria are autotrophs while others are heterotrophs. Use this diagram to answer the question. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to find similarities between humans and a chemoorganoheterotrophic bacterium. o Did you remember that bacteria do not have organelles? Humans and other eukaryotes have mitochondria, but bacteria do not. o Did you recognize that both humans and some bacteria are heterotrophs? This means they consume other organisms (organic molecules) to obtain energy and raw materials, including carbon. 11) A 12) D
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Clarify Question • What is the key concept addressed by the question? o This question asks whether transformation and transduction could be considered the same process. • What type of thinking is required? o This question is an “apply” question. You need to compare and contrast transformation and transduction. Gather Content • What do you already know about transformation and transduction? How does it relate to the question? o Transformation involves obtaining a piece of DNA from the environment and inserting it into your chromosome. How is this done? How does the bacterium obtain the DNA from the environment? Look at the animation on Connect about transformation. o Transduction involves a virus accidentally picking up bacterial DNA instead of viral DNA and injecting it into a new bacterium. o How are these two processes similar? How are they different? Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Make a Venn diagram showing the similarities and differences between transformation and transduction. o Once you’ve started, look at the options for the question and add them to your diagram. Do both “involve the acquisition of viral genes”? Or is that a difference? Which process does it belong to? o Think of the options as arguments. Someone has asked you the question and you need to pick the best argument. First, you need to say Version 1
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whether transformation and transduction are the same thing. Then, you need to provide correct reasoning. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to determine whether transformation and transduction are the same process. You then needed to defend your answer. o If you got the correct answer, great job! o If you got an incorrect answer, where did you get stuck? • Transformation and transduction are not the same process because there are key differences. One involves just picking up DNA from the environment, while the other involves a virus. Were you able to break the options apart into smaller pieces? Doing so can sometimes help with this type of question 13) B
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Clarify Question • What is the key concept addressed by the question? • You have discovered a new bacteria species. You analyze its cell wall and determine that it contains a lot of phospholipids, some proteins, and lipopolysaccharide. Is this a gram-negative or gram-positive bacterium? What color will it be after Gram staining? • What type of thinking is required? o This question is an “apply” question. You need to apply your previous knowledge (about gram staining, gram-negative bacteria, and grampositive bacteria) to a new situation. Gather Content • What do you already know about gram staining? How does it relate to the question? o During gram staining, you use crystal violet and iodine, which stay under the thick peptidoglycan layer of gram-positive cells. In gramnegative cells, the purple dye escapes. o You then use safranin, which stains all of the cells. The gram-positive cells are already purple, so their color does not change much. The gramnegative cells change from clear to pink. o Are the bacteria gram-positive or gram-negative? How are the cell walls of these two groups different? Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Which type of bacterium is going to have a lot of phospholipids, a few proteins, and lipopolysaccharide in its cell wall? A gram-negative bacterium. Version 1
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o And what color will a gram-negative bacterium be after Gram staining? Pink. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question gave you information about a new bacterium, then asked you to determine what color it would be after a gram stain. The question required a two-step process to answer. First, you needed to determine whether the bacteria are gram-positive or gram-negative. Then, you needed to use that information to determine what color they would be after a Gram stain. o If you got the correct answer, great job! o If you got an incorrect answer, where did you get stuck? • The bacteria had a lot of phospholipids, a lipopolysaccharide, and a few proteins in its cell wall. Did you figure out whether it was grampositive or gram-negative? • Gram-positive bacteria have a huge layer of peptidoglycan for a cell wall. • Gram-negative bacteria have a thin layer of peptidoglycan surrounded by the plasma membrane on one side and the outer membrane on the other. These membranes are made of phospholipids and proteins, and have lipopolysaccharide. 14) B
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Clarify Question • What is the key concept addressed by the question? o You need to determine which option best explains how bacterial cells avoid being detected by the host’s immune system. • What type of thinking is required? o This question is an “apply” question. You need to use your knowledge of bacterial anatomy and apply it to this new situation. Gather Content • What do you already know about bacterial cell walls? How does it relate to the question? o Bacteria can be gram-positive, with a cell wall made of a thick layer of peptidoglycan (a lipopolysaccharide). o They can also be gram-negative, with a cell wall made of a thin layer of peptidoglycan sandwiched between the plasma membrane and the outer membrane. o The cell wall has several purposes. It protects the cell from damage. It also keeps the cell from bursting if it is put in a hypotonic solution. What do you know about the cell walls of pathogenic bacteria? What do they do to keep the hosts’ immune system from recognizing them? Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Pick any pathogenic bacterium you remember from class or the textbook. Does it have a cell wall? What is the cell wall made of? Read over the options. There are a couple you can cross off fairly easily. Then, review the information in the text to choose between the last couple options. Version 1
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to explain how pathogenic bacteria can avoid the immune cells if the immune cells can detect peptidoglycan. o If you got the correct answer, great job! o If you got an incorrect answer, where did you get stuck? • All bacteria have cell walls, but many pathogenic ones also have a gelatinous capsule. This capsule allows them to stick to surfaces and avoid detection. There is more information about this in your text. 15) A
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Clarify Question • What is the key concept addressed by the question? o You are observing a new microorganism under the microscope. You see a cell replicate its chromosomes and divide into multiple daughter cells, but each daughter cell has fewer chromosomes than the original parent cell. How would you classify this new organism? • What type of thinking is required? o This question is an “apply” question. You need to use your knowledge about the different taxa (eukaryotes, prokaryotes, viruses) and how they replicate to answer the question about this new organism. Gather Content • What do you already know about cell replication? How does it relate to the question? o Cells can replicate in a number of ways, including: binary fission, mitosis, meiosis, and lysogenesis. Which of these types of replication is found in bacteria? in archaea? in eukarya? in viruses? o Review each of these types of cell replication and division. Which of them produces daughter cells that have fewer chromosomes than the original parent cell? Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o First, figure out which type of cell replication produces daughter cells with fewer chromosomes than the parent cell. o Now that you’ve figured out which process you observed under the microscope, which group of organisms can do this process?
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to classify a new microorganism based on the fact that you observed the microorganism replicate and produce daughter cells that had fewer chromosomes than the original parent cell. o If you got the correct answer, great job! o If you got an incorrect answer, where did you get stuck? • There is only one type of cell replication that involves a decrease in chromosome number: meiosis. Meiosis produces daughter cells that each have half the chromosomes of the original parent cell. If the parent cell was diploid, it produces four haploid daughter cells. • Eukaryotes are the only organisms that do meiosis. Did you know that there are single-celled eukaryotes? In fact, most eukaryotes are single-celled. 16) C
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Clarify Question • What is the key concept addressed by the question? o You observe that in some ways eukaryotes are more similar to archaea than to bacteria. Which hypothesis best explains this observation? • What type of thinking is required? o This question is an “evaluate” question. You must use your previous knowledge, along with logic and reason, to determine which hypothesis best explains the observed phenomenon. Gather Content • What do you already know about phylogenetic trees? How does it relate to the question? o How do phylogenetic trees help explain how organisms are related to each other? These trees use similarities and differences to map out relatedness. If two organisms are very similar, they are likely to be closely related. How would you draw a phylogenetic tree of the three domains? Are all three equally related? If so, they would all branch out of the same node. Are two domains more similar to each other? If so, first one domain branches off, then the other two. o Scientists used to think that Bacteria and Archaea were closely related to each other because they are both prokaryotes. These two domains were grouped together, and Eukarya was their “cousin” on the tree. Does modern evidence agree with this? What would a modern tree of the three domains look like? Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o You can evaluate some of these options using probability. What is the Version 1
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probability that life originated on Earth twice? Is it greater or less than the probability that Eukaryotes are related to Archaea? o Next, think about what you know of phylogenetic trees. If Eukaryotes are more similar to Archaea, does that mean that Archaea are not related to Bacteria at all? Does it mean that Eukaryotes evolved from modernday Archaea? Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to pick the hypothesis that best explains why Eukaryotes are more similar to Archaea than to Bacteria. o If you got the correct answer, great job! o If you got an incorrect answer, where did you get stuck? • Did you think that Eukaryotes descended from modern Archaea because they are so similar? Eukaryotes did not descend from modern Archaea, just like you did not descend from your sibling. The two domains descended from a common ancestor, and that common ancestor was more recent than the common ancestor with Bacteria. Think of Eukarya and Archaea as sisters, both descended from a mother. Bacteria is their cousin, related to them through everyone’s grandmother. • Phylogenetic trees are sometimes difficult to understand at first. If you are struggling with this concept, talk to your instructor or TA and try to do more practice problems. The best way to build understanding and confidence for this concept is practice! 17) B
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Clarify Question • What is the key concept addressed by the question? o If you had a slide of a gram-positive bacillus bacterium that was stained using the Gram staining process, what would it look like? • What type of thinking is required? o This question is an “apply” question. You need to combine your knowledge from two different areas (Gram staining and bacterial shapes) to answer the question. Gather Content • What do you already know about Gram staining? How does it relate to the question? o During gram staining, you use crystal violet and iodine, which stay under the peptidoglycan layer of gram-positive cells. In gram-negative cells, there are pores between sections of the peptidoglycan layer, which allow the crystal violet and iodine to escape. o You then use safranin, which stains all of the cells. The gram-positive cells are already purple, so their color does not change much. The gramnegative cells change from clear to pink. • What other information is related to the question? Which information is most useful? o Bacteria can be round, rod-shaped, or spiral-shaped. They can also be in chains, pairs, or clusters. What vocabulary do terms describe each of these shapes and arrangements? Try looking up bacillus, coccus, spirochete, Diplo, and strep. Choose Answer • Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer? Version 1
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o First, figure out which color the bacteria should be. Then figure out what shape the bacteria should be. For an option to be correct, both parts of the answer need to be correct. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to determine what a gram-positive bacillus would look like. o If you got the correct answer, great job! o If you got an incorrect answer, where did you get stuck? • Gram-positive bacteria are purple after a gram staining procedure. Bacilli are rod-shaped. Cocci are round, and spirochetes are spiralshaped. 18) C
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Clarify Question • What is the key concept addressed by the question? o You have discovered a new bacterium in a lake. After careful analysis, you isolate brightly-colored, chlorophyll-like pigments from its plasma membrane. How does this bacterium get energy? • What type of thinking is required? o This question is an “apply” question. You need to apply your knowledge of bacterial metabolism to a new situation. Gather Content • What do you already know about bacterial metabolism? How does it relate to the question? o In general, bacteria can either produce their own energy or get energy by consuming other organisms. Autotrophic organisms produce their own energy (auto = self). Heterotrophic organisms get energy by consuming others (hetero = other). o Bacteria such as cyanobacteria get energy from sunlight by doing photosynthesis. Are these bacteria autotrophs or heterotrophs? o Bacteria such as rhizobia, which live in legume roots, get energy by oxidizing nitrogen. These bacteria are categorized as chemolithotrophs. There are a variety of chemolithotrophs, and they can oxidize nitrogen, sulfur, or hydrogen. Some live at the bottom of the ocean next to volcanic vents. Are these bacteria autotrophs or heterotrophs? • What other information is related to the question? Which information is most useful? o Chlorophyll is a green pigment found in a variety of organisms, including many green plants. What is it used for? Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o This question can actually be broken into two parts. First, determine whether the organisms is a chemotroph or a phototroph. Then determine whether the organisms is an autotroph or a heterotroph. Use this information to pick between the four options. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to determine the type of metabolism used by a bacterium that has a lot of chlorophyll-like pigment in its membrane. o If you got the correct answer, great job! o If you got an incorrect answer, where did you get stuck? • Did you figure out that chlorophyll is used for photosynthesis? Green plants have it in their chloroplasts and cyanobacteria have it embedded in their plasma membranes. Your new bacterium probably does photosynthesis to get energy. So your bacterium is likely a photoautotroph. 19) E
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Clarify Question • What is the key concept addressed by the question? o You are a doctor, and your patient has a Staphylococcus aureus infection. You would normally treat this patient with methicillin, but you suspect that this strain is resistant to methicillin. You get some of the bacteria using a sterile Q-tip. What do you do now? • What type of thinking is required? o This question is an “evaluate” question. You should consider the background information, then determine which of the five options would give you the answer you need. Gather Content • What do you already know about antibiotic resistance? How does it relate to the question? o Generally, a bacterium has a gene that codes for particular proteins that make it resistant to an antibiotic. For example, if the antibiotic stops a cellular enzyme from functioning, the resistance gene could code for a slightly different version of the enzyme, one that is not affected by the antibiotic. o Resistance genes generally occur on R plasmids. A single bacterium could have multiple resistance genes, giving it resistance to multiple antibiotics. • What other information is related to the question? Which information is most useful? o It is important for scientists to design experiments that will actually answer their question. Which of the options will answer the question you are asking? Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Look at the answers and assess them one-by-one. Which one will tell you whether the strain from your patient is resistant to methicillin? o Remember, you want a method that is cheap, reliable, and fast. You need to treat this patient as soon as possible. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to pick an experiment that would quickly tell you whether your patient’s strain of S. aureus is resistant to methicillin. o If you got the correct answer, great job! o If you got an incorrect answer, where did you get stuck? • Did you remember that R plasmids are small circles of DNA in the cell? They can integrate into the bacterial chromosome, but they aren’t always there. Sequencing the bacterial chromosome will not necessarily find an R plasmid. • The fastest way to tell whether the strain is resistant is to expose it to methicillin and see if the bacteria can grow. If you put a sample in a tube with growth medium and methicillin, and the tube becomes cloudy with bacteria, you know that the strain is resistant. This procedure is frequently done in hospitals. 20) D 21) D 22) B 23) C 24) D 25) D Version 1
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26) C 27) B 28) C 29) A 30) E 31) D 32) C 33) E 34) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the bacteria that form dental plaque. ● What type of thinking is required?● This question is an “apply” question. You need to use your knowledge and apply it to this specific question. Gather Content● What do you already know about the bacteria that form dental plaque? How does it relate to the question?● The bacteria that form plaque on the teeth are Streptococcus mutans. They also cause caries or cavities. ● The picture in the textbook showed an electron micrograph of the biofilm formed by these bacteria. ● What other information is related to the question? Which information is most useful?● Biofilms are complex, structured colonies of bacteria, that are known for being tough and resistant to environmental insults. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Could the bacteria be harder to kill because of temperatures or nutrients in the mouth? Possible, but seems unlikely since the lab conditions would need to get these about right to grow them. ● Do they form endospores in the mouth? That seems unlikely since this is their normal environment when they need to be actively metabolizing and dividing. ● Since we know that dental plaque bacteria form a biofilm, and biofilms are tough and resistant, the best answer is "On teeth, they form Version 1
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a complex, resistant biofilm." Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to apply what you knew to the question of dental plaque. ● Did you remember that plaque is a type of biofilm? ● Did you recognize that biofilms are known for being tough and resistant? 35) D 36) B 37) B 38) A 39) D 40) E 41) A 42) C 43) A 44) A
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Clarify Question • What is the key concept addressed by the question? o You are trying to use conjugation to map the locations of five genes on a bacterial chromosome. Which gene is physically located closest to gene 1 on the chromosome? • What type of thinking is required? o This question is an “analyze” question. You should read the four options and determine which one is most likely closest to gene 1. Gather Content • What do you already know about conjugation? How does it relate to the question? o During conjugation, a copy of the F-plasmid is transferred through the sex pilus into the recipient cell. If the F-plasmid has been inserted into the chromosome, the entire chromosome could be transferred. o This question is about a process commonly used to map the genes on a bacterial chromosome. You allow conjugation to start, then remove some cells and agitate them in a blender. You can then find out which genes have been transferred to the recipient cells. You repeat this process after 30 minutes, 40 minutes, etc., until the entire chromosome has been transferred. Which gene is transferred to the donor cells earliest? Gene 1 is transferred first. You know this because it shows up after only 30 minutes. Which gene is transferred next? • What other information is related to the question? Which information is most useful? o You can assume that the DNA is transferred at a steady rate to the recipient cells. If this is true, and the entire chromosome is 100 minutes “long”, how many minutes are between gene 5 and gene 1 (remember, the chromosome is circular). Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Draw a line to represent the chromosome (it can be straight instead of circular). Treat minutes as if they are a distance, and write down the distance between each gene as it is transferred into the recipient cell. It may help to draw the donor and recipient cells, with the sex pilus connecting them. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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o This question asked you to choose which gene is physically closest to gene 1 on the chromosome. o If you got the correct answer, great job! o If you got an incorrect answer, where did you get stuck? • The location of genes on a bacterial chromosome can actually be described in seconds or minutes because this method is how the genes are mapped. • From the origin to gene 1 is 30 minutes. • From gene 1 to gene 2 is 10 minutes. • From gene 5 to the end is 10 minutes, if you add this to the distance between the origin and gene 1, you will find that gene 1 and gene 5 are 40 minutes apart. • Gene 2 is therefore the closest to gene 1.
45) D 46) A 47) A
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Clarify Question • What is the key concept addressed by the question? o The options list various processes a bacterium could undergo. Which process is least likely to result in the bacterium getting new DNA? • What type of thinking is required? o This question is an “evaluate” question. You need to judge the probability of each option resulting in genetic change. You should then pick the option that has the LEAST probability of the bacterium getting new DNA. Gather Content • What do you already know about horizontal gene transfer? How does it relate to the question? o Horizontal gene transfer occurs when the DNA from a donor cell is inserted into the DNA of a receiving cell. This DNA could be new or could look like the original DNA. There are three types of horizontal gene transfer: conjugation, transformation, and transduction. o Conjugation occurs when a donor cell attaches to a recipient cell using a sex pilus. The donor cell then transfers a copy of the F-plasmid to the recipient cell. o Transduction occurs when a virus accidentally picks up DNA from an infected bacterium’s chromosome. It then inserts this DNA into the next bacterium that the virus infects. o Transformation occurs when a bacterium picks up DNA from its environment, either by taking in free-floating DNA or by taking DNA from a cell it just consumed using phagocytosis. The bacterium inserts this segment of DNA into a similar region in its own chromosome. Sometimes this new DNA contains new genes. These new genes could be beneficial or detrimental. Version 1
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Look at each option and picture the process in your mind. It may help to draw cartoons of each process. Which ones involve DNA transfer? Which direction is the DNA moving? What is the probability that the recipient cell will get any DNA at all? Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to determine which of the options would be the least likely to result in a change in the bacterium’s genotype. o If you got the correct answer, great job! o If you got an incorrect answer, where did you get stuck? • Four of the options discuss processes of horizontal gene transfer. All four have relatively the same probability of a bacterium getting new DNA. • “Pilus formation” is different. Bacteria can form pili that are not sex pili. These pili are used for movement or to pull the bacterium closer to a surface. If it is a sex pilus, it will only form on a donor cell, and donor cells do not get new DNA. 48) D
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Clarify Question • What is the key concept addressed by the question? o The question describes two types of bacteria and the medium they are growing in. You need to determine whether each strain of bacteria will survive. • What type of thinking is required? o This question is an “analyze” question. You need to use your knowledge of bacterial growth to pick the most likely answer. Gather Content • What do you already know about the bacteria? How does it relate to the question? o In this question, you have two strains of bacteria: “wild-type” and a mutant. • The wild-type bacteria are the normal strain. • The mutant bacteria are auxotrophic for the nutrient zinc. The growth medium does not contain zinc. Will the mutant bacteria thrive or suffer on this type of growth medium? • What other information is related to the question? Which information is most useful? o The growth medium does not contain zinc. Also, it contains an antibiotic that kills growing bacteria. Is there a way bacterial cells could survive this environment? Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Treat this question as a short-answer question. Write down your answer for each of the bacterial strains separately. Now, find the option Version 1
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that gives the correct answer for BOTH strains. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to determine what would happen to two different bacterial strains grown in the same medium. o If you got the correct answer, great job! o If you got an incorrect answer, where did you get stuck? • This is a very complicated question, and you had to come up with the correct answer for each of the strains. In a question like this, it is best to break it into pieces. For example, focus on just the wild-type strain first. Will it survive or die? Then, focus on just the mutant strain. This makes the question easier. 49) B 50) C 51) B 52) D 53) Archaea 54) peptidoglycan 55) Streptococcus
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Chapter 28 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) Protist locomotion is accomplished by the contraction of macronuclei. ⊚ ⊚
true false
CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 2) Which are features of mitochondria that reflect their endosymbiotic origin? (Choose all that apply.) A) They have their own circular genome. B) They replicate via meiosis, just like bacteria. C) Mitochondria genes are translated by ribosomes similar to bacterial ribosomes. D) Antibiotics disrupt the cell walls of mitochondria.
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 3) Sponges (phylum: Porifera) are animals that possess feeding cells called collar cells. These cells have a central flagellum surrounded by a collar of microvilli. The collar filters organic matter out of the water column. Which protists share a most recent common ancestor with the poriferans? A) ciliates B) rhodophytes C) choanoflagellates D) radiolarians E) myxomycetes
4)
The Irish potato famine in the 1840's was caused in large part by a proliferation of a(n)
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A) Paramecia. B) Oomycete. C) Dinoflagellate. D) Chlorophyte. E) Fungus.
5) What type of cellular damage in a malarial parasite would prevent it from penetrating a red blood cell? A) Mutation in thevariable surface glycoprotein genes B) Disruption of the cytoskeletal proteins in the apical complex C) Failure of the cross-linking of the peptidoglycans in the cell wall D) Damage to the flagellum and contractile collar of the choanocyte
6) Which feature unites paramecia, malarial parasites, and dinoflagellates into a single group? A) The use ofcilia B) A parasitic lifestyle C) The presence of anucleus D) The type ofribosomes E) The possession ofalveoli
7) Transferring Euglena into a dark environment results in the loss of photosynthetic pigment. What conclusion does this support? A) Euglenoids are obligate photoautotrophs. B) Light triggers heterotrophy. C) Euglenoids are closely related to plants. D) Euglenoids are neither plant-like or animal-like protists.
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8) A patient presents in an ER with severe stomach cramps and diarrhea. She was recently swimming in unclean water. Which protist would be the most likely cause of her symptoms? A) Toxoplasma gondii B) Plasmodium C) Leishmania D) Giardia
9) During cell division the progeny of a trypanosome express a different variable-surface glycoprotein (VSG) gene than their parents. Why is this done? A) To hide from the host's immune system. B) To signal endocytosis of the parasites. C) VSG genes inhibit phagocytosis. D) VSG genes activate photoheterotrophy.
10)
What would be strong evidence to suggest a protist is phagotrophic? A) An abundance of lysosomes B) Locomotion using flagella C) Silica plates or cell walls D) Benthiclifestyle E) Presence of chloroplasts
11)
What would be strong evidence to suggest a protist is phototrophic? A) Many lysosomes B) Locomotion via flagella C) The presence ofchloroplasts D) Silica plates or cell walls E) A benthic lifestyle
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12) If a researcher wants to create a phylogeny showing relationships of different groups of algae, which type of DNA would be best to compare, and why? A) Chloroplast DNA, because it will reflect algal relationships better than nuclear DNA. B) Nuclear DNA, because chloroplast DNA will reflect primary and secondary endosymbiosis. C) Mitochondrial DNA, because only chloroplasts are from endosymbiosis. D) Chloroplast DNA, because it is unique to algae.
13) A biologist uses a time machine to collect living material from two different time periods. Sample A is 3 billion years old, and sample B is 1.5 billion years old. How would these samples differ? A) Prokaryotic organisms would be abundant in sample A but absent from sample B. B) Eukaryotic organisms would be present in both samples but much more common in sample B. C) Prokaryotic organisms would only occur in sample B. D) Eukaryotic organisms would be absent from sample A.
14)
The common characteristic of Alveolata is A) a single, unique mitochondria. B) a layer of flattened vesicles beneath the plasma membrane. C) silica covering. D) funnel-shaped, contractile collar. E) presence of a plasmodium.
15)
A common characteristic of choanoflagellates is
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A) a single, unique mitochondria. B) space beneath the plasma membrane. C) silica covering. D) funnel-shaped, contractile collar. E) presence of a plasmodium.
16)
Amoebas move from place to place by means of their A) cysts. B) pseudopods. C) pseudomonads. D) sporocarps. E) plasmodia.
17)
The marine multicellular protists including the larger brown algae belong to the A) dinoflagellates. B) choanoflagellates. C) stramenopiles. D) euglenids. E) foraminifera.
18) Organisms that are characterized by being unicellular, photosynthetic, and having double shells made of silica are known as A) dinoflagellates. B) diatoms. C) kelps. D) euglenids. E) foraminifera.
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19) The tropical diseases such as African sleeping sickness, Chagas disease, and leishmaniasis are caused by A) foraminifera. B) sporozoans. C) phytomastigotes. D) trypanosomes. E) oomycetes.
20) All_________blank have two very different types of nuclei within their cells, small micronuclei and larger macronuclei. A) sporozoans B) protists C) oomycetes D) ciliates E) dinoflagellates
21)
The parasite that is responsible for causing malaria is called A) Paramecium. B) Chlamydomonas. C) Plasmodium. D) Entamoeba. E) Giardia.
22)
Protists are classified into a single kingdom because of which of the following features?
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A) They are eukaryotes, but not fungi, plants, or animals. B) They are microscopic. C) They are unicellular. D) All types of nutritional modes are found. E) They are monophyletic.
23)
Which of the following is true about Euglena? A) They belong to the same phylum as Paramecium. B) They do not have flagella. C) They can be both autotrophs and heterotrophs. D) They lack chloroplasts. E) They have sexual reproduction.
24) The organism, Phytophthora infestans, responsible for the Irish Potato Famine of 1845 and 1847 belongs to A) Euglenozoa. B) Alveolata. C) Rhodophyta. D) Chlorophyta. E) Stramenopila.
25)
Oomycetes are characterized by all of the following except they A) produce zoospores asexually. B) are able to reproduce sexually. C) contain motile spores. D) contain two unequal flagella. E) are consideredfungi.
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26)
The unique double shells of diatoms are made of A) cellulose. B) silica. C) chlorophylls. D) agar. E) proteins.
27) The White Cliffs of Dover, a famous landmark in England, is made of limestone, which is really a collection of the pore-studded shells (tests) of A) diatoms. B) dinoflagellates. C) brown algae. D) spirochetes. E) foraminifera.
28)
Which of the following is NOT one of the distinctive features of dinoflagellates? A) They are unicellular. B) They are photosynthetic. C) Some exist in fresh water, while some are part of marine plankton. D) They form large, spherical colonies. E) Some planktonic members are luminous and cause flashes in the night.
29)
Trypanosomiasis is spread by
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A) mosquitoes. B) airborne droplets. C) tsetse flies. D) fleas on rats. E) contaminated water.
30)
Vacuoles for ingesting food and regulating their water balance are characteristic of A) sporozoans. B) trypanosomes. C) ciliates. D) algae. E) spirochetes.
31)
In addition to their characteristic cilia, most ciliates contain two types of A) nuclei. B) chloroplasts. C) flagella. D) wood-digesting enzymes. E) cysts.
32) Conjugating ciliates exchange a pair of haploid micronuclei that undergo mitosis as a diploid micronucleus, while the macronucleus in each A) is expelled from the cell. B) disintegrates. C) divides by meiosis. D) fuses with each other. E) shrinks and becomes diploid micronuclei.
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33)
The malarial parasite, Plasmodium, is a member of the group A) Euglenozoa. B) Stramenopiles. C) Alveolata. D) Rhodophyta. E) Diplomonads.
34) Some protists use cell division preceded by several nuclear divisions as a means of reproduction. What is the name of this process? A) budding B) zygotic meiosis C) schizogony D) syngamy E) intermediary meiosis
35)
Members of the Euglenozoa move about using A) tests. B) pseudopodia. C) cilia. D) flagella. E) contractile vacuoles.
36)
In addition to the true amoebas (Rhizopoda), another group with pseudopods are the A) Euglenozoa. B) Stramenopila. C) Radiolarians. D) Diplomonads. E) Alveolata.
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37) Which is NOT a feature that is similar between mitochondria, chloroplasts, and their bacterial relatives? A) Cell walls B) Circular genomes C) Ribosomes D) Binary fission E) Susceptibility to antibiotics
38) Some photosynthetic euglenids can also ingest dissolved or particulate food. Which one of the following terms would best describe such a protist? A) autotrophic B) heterotrophic C) mixotrophic D) osmotrophic E) phagotrophic
39)
Which of these is NOT part of the life cycle of brown algae? A) meiosis B) multicellularhaploid stage C) multicellular diploid stage D) gametes produced by mitosis E) spores produced by mitosis
40)
Which option describes BOTH plasmodial and cellular slime molds?
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A) Form a multinucleate mass of cytoplasm B) Produce spores C) Signal between cells using cAMP D) Form a slug, then a fruiting body E) Have synchronized mitosis, without centrioles
41)
What best summarizes the process of conjugation in ciliates? A) Involves combining eggs and sperm. B) Uses binary fission, not meiosis or mitosis. C) Micronuclei are exchanged, then macronuclei are replaced. D) Requires injection of DNA from the apical complex. E) One mating type is small, the other much larger.
42)
Which one of the following statements about diplomonads and parabasalids is false? A) Absence of mitochondria in these groups is an ancestral trait. B) Some members are parasitic, but some also engage in mutualism. C) Diplomonads and parabasalids belong to different clades D) Both groups are flagellated protists.
43)
Why is the disease African sleeping sickness difficult to control? A) Trypanosomes change their glycoprotein coat antigens to evade antibodies. B) Ciliates can trade DNA by conjugation. C) Euglenids can photosynthesize to survive outside the host. D) Endosymbiosis allows them to evade the immune system. E) It is easily transmitted by contaminated drinking water.
44)
Which of the following statements about malaria is false?
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A) Fertilization occurs within a mosquito. B) Merozoites are found inside red blood cells. C) Gametocytes develop from merozoites. D) Sporozoites are only found within a mosquito. E) Gametocytes are passed to a feeding mosquito.
45)
How do protists provide evidence for the evolution of mitosis? A) In some protiststhe nuclear membrane fails to breakdown during mitosis. B) Protists use conjugation instead of mitosis. C) Only meiosis occurs in protists. D) Mitosis has not been observed in any protist species.
46) A new protist species is discovered with these characteristics: contains phycoerythrin and phycocyanin, lacks flagella and centrioles, photosynthesizes, haplodiplontic, and lives in coral reefs. What group does it likely belong to? A) Charophytes B) Chlorophytes C) Rhodophytes D) Stramenopiles E) Amoebozoa
47)
How do humans use red algae polysaccharides? A) Thickeners B) Herbicides C) Adhesives D) Detergents
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48) What features of charophytes provides evidence for charophytes being the closests relative to land plants? A) Charophytespossess plasmodesmata. B) Charophytes arethe only photosynthetic protists. C) Charophytes arefully terrestrial. D) Charophytesproduce seeds and flowers.
49)
Which phrase best describes the characteristics of plasmodial slime molds? A) Plasmodial slime molds consist of large multinucleate single cells. B) Plasmodial slime molds consist of large single nucleate cells. C) Plasmodial slime molds are multicellular. D) Plasmodial slime mold cells contain a pellicle.
50)
Which one of these groups is NOT one of the five supergroups of protists? A) Ascomycota B) Ophisthokonta C) SAR D) Amoebozoa E) Archaeplastida F) Excavata
FILL IN THE BLANK. Write the word or phrase that best completes each statement or answers the question. 51) The_________blank are a group within the Euglenozoa that have a unique, single mitochondrion with minicircles and maxicircles of DNA linked in chains.
52)
The members of_________blank include dinoflagellates, apicomplexans, and ciliates.
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53)
All apicomplexans are nonmotile, spore forming, and live as_________blank in animals.
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Answer Key Test name: Chap 28_13e_Raven 1) FALSE 2) [A, C] 3) C
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Clarify Question What is the key concept addressed by the question? ● The question is asking you to determine which of the options shares a most recent common ancestor with Porifera. On a family tree, you and your sister would share a more recent common ancestor than you and your cousin. Look at the Eukarya family tree. Which groups have more recent common ancestors with Porifera? What type of thinking is required? ● This question is an “apply” question, so it is asking for you to use the knowledge you already have about reading phylogenetic trees to figure out the most recent common ancestor of Porifera. Gather Content What do you already know about Porifera? How does it relate to the question? ● Porifera are in Kingdom Animalia. Where is Kingdom Animalia on the Eukaryote family tree? ● Common ancestors are populations that were originally one species, but diverged into two species. They can be seen as nodes on a phylogenetic tree. ● More closely related groups tend to have more traits in common. In this case, close relatives to Porifera are likely to have a similar feeding collar. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● Now that you know Porifera are in Kingdom Animalia, find them on the Eukaryote family tree. If you have a pencil, circle them. Now trace Version 1
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your finger back along the branch that becomes Animalia. When it joins another line, you have found a common ancestor. Let’s call that ancestor “Mom”. How many daughters does Mom have? Now trace the line back farther to find the next common ancestor. Let’s call that ancestor “Grandma”. How many granddaughters does Grandma have? Which of the options are a sister to Porifera? Which of the options are a cousin to Porifera? Are there second-cousins? Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked to you figure out which group was most closely related to Porifera. To answer this question correctly, you needed to apply your knowledge about phylogenies to the Eukaryote family tree. ● If you got the correct answer, great job! Keep using the strategy you used here on other “apply” questions. ● If you got the incorrect answer, where did the process break down? Did you remember that the closest relatives share the most recent common ancestor? Did you have trouble reading the phylogenetic tree? Reading phylogenies is difficult, and many students struggle with it at first. You should go back to the chapter on reading phylogenies to brush up. If you are still having difficulty, go talk to your professor or TA. Once you understand phylogenies, questions like this will be a lot easier. 4) B 5) B
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Clarify Question What is the key concept addressed by the question? ● This question is asking you to determine which type of damage to the Plasmodium cell would prevent it from entering a red blood cell. Many of the options would damage the Plasmodium, possibly killing it, but only one would prevent it from entering a red blood cell. Gather Content What type of thinking is required? ● This question is an “apply” question, so it is asking for you to take a concept you already know (the anatomy of Plasmodium) and apply it to a new scenario to solve the problem. What do you already know about Plasmodium? How does it relate to the question? ● Plasmodium is a member of the Apicomplexans. This group of protists is able to invade host cells using the apical complex. How does the apical complex work? What sort of damage would prevent the apical complex from working? Choose Answer Given what you now know, what information and/or problem-solving approach is most likely to produce the correct answer? ● Plasmodium is able to infect red blood cells using its apical complex. How does the apical complex work?● Does it use surface proteins? ● Does it use the cytoskeleton? ● Does it depend on peptidoglycans? ● Does it use choanocytes? ● You might be able to rule out some of the answers if they do not occur in protists. Version 1
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to determine which type of damage to Plasmodium would prevent it from infecting red blood cells. Answering this question required you understand how an apical complex works. You then had to apply this information to determine which type of damage would prevent the apical complex from working. ● If you got the correct answer, great job! ● If you got an incorrect answer, where did you get stuck?● Did you remember that peptidoglycans only occurs in Bacteria? ● Did you remember that the apical complex depends on the cytoskeleton and secretory glands? 6) E
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Clarify Question What is the key concept addressed by the question? ● This question asks you to compare what you know about paramecia, malarial parasites, and dinoflagellates. What characteristics do these three taxa have in common? What type of thinking is required? ● This question is an “apply” question, so it is asking for you to take a concept you already know (each of these taxa individually) and apply it to a new scenario to solve the problem. Gather Content What do you already know about each of these three groups? How does it relate to the question? ● Do all three have cilia? a nucleus? alveoli? ● Are they all parasitic? ● Do they all have the same type of ribosomes? What other information is related to the question? Which information is most useful? ● Once you have figured out the traits all three groups have in common, you need to address the other part of the question: Which of these traits unites the three taxa on the phylogenetic tree? Choose Answer Given what you now know, what information and/or problem-solving approach is most likely to produce the correct answer? ● Look at the Protist family tree. Which traits do these three taxa have but the other Protists do not? All three taxa probably have mitochondria, but so do the other Protists, so that feature isn’t particularly useful when grouping taxa on the family tree. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to determine which of the traits unites the three taxa on the phylogenetic tree. Answering this question required you to:● compare the traits of the three taxa to see which traits they have in common ● compare the three taxa to the other protists to see which traits are unique to these three taxa. ● If you got the correct answer, great job! ● If you got an incorrect answer, where did you get stuck?● Did you choose “the presence of a nucleus”? While paramecia, sporozoans, and dinoflagellates all have nuclei, so do all of the other protists. This trait cannot be used to group these three taxa on the tree. ● Did you look at the tree? Did you notice that these three taxa are grouped under “Alveolata”? The names of groups can give you a hint as to the distinguishing feature that grouped the taxa together. 7) D
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Clarify Question What is the key concept addressed by the question? ● This question is asking you to determine which statement is supported by the results of an experiment where Euglena was moved from light to dark. What type of thinking is required? ● This is an “evaluate” question, so you need to look at each option and evaluate whether the results of your experiment support your conclusion. Remember, you moved Euglena from the light into the dark and saw the photosynthetic pigment disappear. Gather Content What do you already know about Euglena? How does it relate to the question? ● What sort of photosynthetic pigments have you learned about? One is chlorophyll, which is essential for photosynthesis. The very first step of photosynthesis involves chlorophyll absorbing energy from sunlight, so it is a very useful pigment. On the other hand, maintaining chlorophyll uses up energy. If a plant does photosynthesis intermittently, during nonphotosynthetic periods it has to use up valuable sugars maintaining its chlorophyll. What other information is related to the question? Which information is most useful? ● What are photoautotrophs? How are they different from heterotrophs? Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● You can go about answering this question in a couple ways:● You have four hypotheses. What experiment would you conduct to test each Version 1
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one? How well does the experiment described in the question’s stem match those methods? ● You have observed that Euglena has photosynthetic pigment when growing in the light, but digests this pigment when growing in the dark. Which conclusion best explains what is going on? ● Be careful when evaluating each option. Some of the statements themselves can be correct without being the correct answer. The correct answer is supported by the results of your experiment. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to evaluate which statement was supported by the results discussed in the stem of the question. Answering the question depended on your ability to evaluate each of the statements. ● If you got the correct answer, well done! ● If you got an incorrect answer, where did the process break down? Did you pick “Light triggers heterotrophy”? Remember, you moved Euglena to the dark, triggering heterotrophy. This statement would be correct if you said “Dark triggers heterotrophy.” 8) D
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Clarify Question What is the key concept addressed by the question? ● You need to determine which parasite has infected the patient so you can give her the correct treatment. What type of thinking is required? ● This is an “apply” question, so you need to use your knowledge about the various parasitic and pathogenic protists and apply this knowledge. Gather Content What do you already know about these organisms? How does it relate to the question? ● Go through the list and write down what you already know about each organism. Does it cause a particular disease? You might find hints in the name, since a scientific name is supposed to describe the species. What other information is related to the question? Which information is most useful? ● Yersinia pestis caused the Black Plague. Do you remember any symptoms of the Black Plague? One of them is a rash that shows up in circular patches, leading to the nursery rhyme lyric, “Ring, a ring of rosies.” What can you find out about the other species? Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● You know two things about the parasite:● It can be transmitted by water (particularly unclean water) ● It causes stomach cramps and diarrhea. ● Which of the organisms meets both criteria? Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you which species is causing the patient's intense cramps and diarrhea. Answering the question depended on your ability to apply what you already know parasitic and pathogenic Protists to a new situation. ● If you got the correct answer, well done! ● If you got an incorrect answer, where did the process break down? Did you need to look up some of the organisms? Not all of them were covered in Chapter 28. 9) A 10) A
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Clarify Question What is the key concept addressed by the question? ● This question gives you five characteristics of a protist. You need to determine which characteristic would tell you that the protist is phagotrophic. What type of thinking is required? ● This question is an “evaluate” question, so it is asking you to judge which of the statements provides the best evidence of phagotrophy. All of the statements could be correct, but only one provides evidence of phagotrophy. Gather Content What do you already know about the nutritional strategies of protists? How does it relate to the question? ● Protists can be autotrophic, heterotrophic, or mixotrophic. ● Autotrophs get their energy from photosynthesis or chemosynthesis. What characteristics would you expect in a protist that does photosynthesis? ● Heterotrophs get their energy by eating things, but single-celled organisms don’t eat things the way we do. An amoeba is an example of a heterotrophic protist. How does an amoeba get food? ● Mixotrophs, such as Euglena, can use either photosynthesis or heterotrophy. What other information is related to the question? Which information is most useful? ● A similar word you may have heard before is “phagocytosis”. Do you remember this vocabulary term from cellular biology? Choose Answer Given what you now know, what information and/or problem-solving Version 1
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approach is most likely to produce the correct answer? ● You know phagotrophy is a nutritional strategy, and that it involves eating things. Which characteristic would be essential for a protist that wants to eat a food particle? Other statements could still be true about the organism, but one of them is essential. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to determine which characteristics would be essential for an organism that is phagotrophic. ● If you got the correct answer, great job! ● If you got an incorrect answer, where did you get stuck?● This was an “evaluate” question, which required you to weigh and judge which piece of evidence would convince you that the protist is phagotrophic. 11) C
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Clarify Question What is the key concept addressed by the question? ● This question gives you five characteristics of a protist. You need to determine which characteristic would tell you that the protist is phototrophic. What type of thinking is required? ● This question is an “evaluate” question, so it is asking you to judge which of the statements provides the best evidence of phototrophy. All of the statements could be correct, but only one provides evidence of phototrophy. Gather Content What do you already know about the nutritional strategies of protists? How does it relate to the question? ● Protists can be autotrophic, heterotrophic, or mixotrophic. ● Autotrophs get their energy from photosynthesis or chemosynthesis. An organism that does photosynthesis would be called “phototrophic”. What characteristics would you expect in a protist that does photosynthesis? ● Heterotrophs get their energy by eating things, but single-celled organisms don’t eat things the way we do. An amoeba is an example of a heterotrophic protist. How does an amoeba get food? ● Mixotrophs, such as Euglena, can use either photosynthesis or heterotrophy. What other information is related to the question? Which information is most useful? ● Think of the different protists that do photosynthesis (for example, green algae and euglena). Is there a trait they all share? Choose Answer
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Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● You know phototrophy is a nutritional strategy, and that it involves getting energy through photosynthesis. Which characteristic would be essential for a protist that wants to do photosynthesis? Other statements could still be true about the organism, but one of them is essential. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to determine which characteristics would be essential for an organism that is phototrophic. ● If you got the correct answer, great job! ● If you got an incorrect answer, where did you get stuck?● This was an “evaluate” question, which required you to weigh and judge which piece of evidence would convince you that the protist is phototrophic. Some protists, like red algae, are able to do photosynthesis with a different organelle, but most use chloroplasts. Of the options you were given, “the presence of chloroplasts” is the best answer because that organelle would allow a protist to do photosynthesis. 12) B
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Clarify Question ● What is the key concept addressed by the question?● The question is asking you which type of DNA would best reveal phylogenetic relationships between algae. ● What type of thinking is required?● This question is an “analyze” question since you have to consider the likely outcomes from using different types of DNA. Gather Content ● What do you already know about DNA in algae? How does it relate to the question?● Both mitochondria and chloroplasts originated from endosymbiosis events. They each have their own DNA, although some genes moved to the nucleus. ● Different groups of algae acquired their chloroplasts through different endoymbiotic events. Osm engulfed cyanobacteria directly, while others engulfed other algae in a secondary or even tertiary endosymbiosis event. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Since the endosymbiotic events were so complex, the history shown by chloroplast DNA is likely to reflect the relationships of the chloroplasts, but not necessarily the relationships of the larger algal cell itself. ● To see the relationships between the host cells, we need to compare nuclear DNA. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result?● This question asked you to determine the best DNA to use for revealing relationships between algae. ● Did you recall that different algae acquired chloroplasts independently, in some cases by secondary endosymbiosis? ● Did you realize how that would make the resulting phylogeny from chloroplast DNA misleading? 13) D
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Clarify Question What is the key concept addressed by the question? ● Biodiversity is the number of species present and how abundant each species is. This question asks you to compare and contrast the biodiversity present on Earth 3 billion years ago with biodiversity present 1.5 billion years ago. What type of thinking is required? ● This question is an “evaluate” question. You should use the information you learned from the text to evaluate which statement is the most accurate. Gather Content What do you already know about Prokaryotes and Eukaryotes? How does it relate to the question? ● When did prokaryotes evolve? When did they become abundant? ● When did eukaryotes evolve? When did they become abundant? Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● Use your answers to the questions in “Gather Content” to predict what would be in each sample. Then, figure out which option in the question best matches your predictions. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to determine what would be present in two different biological samples, one from 3 billion years ago and one from Version 1
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1.5 billion years ago. You needed to use your understanding of Prokaryote and Eukaryote evolution to determine the best answer. ● If you got the correct answer, great job! ● If you got an incorrect answer, where did you get stuck?● The options for this question are complicated because you are answering for both prokaryotes and eukaryotes. For a question like this, it is best to first treat it like a short answer question. Ignore the multiple-choice options and just write down your answer. Then, compare each option to your answer and pick the one that matches. 14) B 15) D 16) B 17) C 18) B 19) D 20) D 21) C 22) A 23) C 24) E 25) E 26) B 27) E 28) D 29) C 30) C 31) A 32) B 33) C
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34) C 35) D 36) C 37) A
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Clarify Question What is the key concept addressed by the question? ● Three of the options are evidence that mitochondria and chloroplasts became organelles through endosymbiosis. You need to find the option that does not provide evidence of endosymbiosis. What type of thinking is required? ● This question is an “evaluate” question. You need to judge which of the options provides the poorest evidence. Gather Content What do you already know about the origin of mitochondria and chloroplasts? How does it relate to the question? ● Mitochondria and chloroplasts were once free-living bacteria. They were engulfed by a larger cell and became endosymbionts. Over a very long period of time, they lost the ability to be free-living and became organelles. What traits do mitochondria and chloroplasts share with bacteria? Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● The endosymbiosis theory states that mitochondria and chloroplasts were once bacteria that were engulfed by a larger, eukaryotic cell. Which option is inconsistent with that theory? Which option does not suggest that mitochondria and chloroplasts were once free-living bacteria? Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? ● This question asked you to determine which statement would not be possible if mitochondria and chloroplasts evolved from endosymbiotic bacteria. ● Bacteria have cell walls, but mitochondria or chloroplasts do not. 38) C 39) E 40) B
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Clarify Question ● What is the key concept addressed by the question?● The question asks you to compare and contrast the traits of plasmodial slime mold and cellular slime mold. ● What type of thinking is required?● This question is an “apply” question. You need to take the traits from each group and compare them. Gather Content ● What do you already know about these two organisms? How does it relate to the question?● Plasmodial slime mold has many nuclei in a single, giant cell, while cellular slime mold has one nucleus per cell. What are other differences between the two groups? Are there any similarities? Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● The best way to answer this question is to make two lists, one with the traits of plasmodial slime mold and one with the traits of cellular slime mold. ● Which of the two taxa has each characteristic? Which option applies to both taxa? Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to compare and contrast plasmodial slime mold with cellular slime mold. ● Did you have trouble finding the similarity between the two groups? Did you recall that despite their differences, both types of slime mold Version 1
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produce spores? 41) C
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Clarify Question ● What is the key concept addressed by the question?● This question asks you to determine which option best describes ciliate conjugation. ● What type of thinking is required?● This question is an “apply” question. You need to use your knowledge of conjugation to answer the question. Gather Content ● What do you already know about ciliate conjugation? How does it relate to the question?● Paramecia have multiple mating types. Only different mating types can conjugate. ● Micronuclei undergo meiosis to make haploid micronuclei, which are exchanged through a cytoplasmic bridge. ● The new micronucleus fuses with one of the old micronuclei, making a new diploid micronucleus. ● After conjugation, the macronucleus in each cell disintegrates, and the new diploid micronucleus undergoes mitosis, giving rise to two diploid micronuclei. One of these micronuclei becomes the precursor of the future micronuclei of that cell, while the other becomes the new macronucleus. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Does ciliate conjugation involves combining eggs and sperm? No. ● Does ciliate conjugation use binary fission? No, it uses both meiosis and mitosis. ● Does ciliate conjugation require an injection of DNA from the apical complex? No. ● Is one mating type small, and the other much larger? No, mating types Version 1
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look the same on the outside. ● In ciliate conjugation, are micronuclei exchanged, then macronuclei replaced? Yes, this summarizes the process. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question asked you to choose the option that best summarized ciliate conjugation. ● Did you recall that micronuclei are exchanged? Did you understand that after fusion, the new diploid micronucleus is used to create a new macronucleus? 42) A 43) A 44) D 45) A
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Clarify Question What is the key concept addressed by the question? ● This question is asking you to explain which part of protist mitosis shows that mitosis evolved step by step, not all at once. What type of thinking is required? ● This question is an “apply” question, so you need to apply what you already know about protist mitosis to a new situation. It is also an “evaluate” question because you need to assess which statement provides the best evidences of a step-wise evolution of mitosis. Gather Content What do you already know about mitosis in protists? How does it relate to the question? ● Prokaryotes divide by binary fission, while eukaryotes divide by mitosis. Protists divide using an interesting early version of mitosis. In what ways is their cell division similar to eukaryotes? In which ways is it different? What other information is related to the question? Which information is most useful? ● Generally, in eukaryotes, mitosis occurs in the following steps:● chromosomes replicate and condense ● the nuclear envelope breaks down ● chromosome pairs are separated and moved to either side of the cell ● two nuclear envelopes form ● the cell divides (cytokinesis) ● Which of these steps is present in protists? Which are absent? Choose Answer Given what you now know, what information and/or problem solving Version 1
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approach is most likely to produce the correct answer? ● Review what you know about protists. Do they do mitosis? Do they do meiosis? ● What is conjugation? What steps does it involve? Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to find the statement that provides the best evidence that mitosis evolved step by step. ● If you got the correct answer, great job! ● If you got an incorrect answer, where did you get stuck?● Did you remember that protists use both conjugation and mitosis? Look at the diagram of conjugation, and you’ll see that mitosis is part of conjugation. 46) C
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Clarify Question ● What is the key concept addressed by the question?● This question is asking you to identify the type of protist based on its characteristics. ● What type of thinking is required?● This question is an “apply” question, so you need to apply what you already know about protist features to identify this one. Gather Content ● What do you already know about different protists that photosynthesize? How does it relate to the question?● The photosynthetic protists are generally called "algae". There are brown algae, red algae, and green algae. ● What other information is related to the question? Which information is most useful? Choose Answer Reflect on Process ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Is it likely a charophyte? No. They have green chlorophyll, not red pigments. ● Is it likely a chlorophyte? No. They have green chlorophyll, not red pigments. ● Is it likely a stramenopile? No. They have flagella with fine hairs. ● Is it likely an amoebozoan? No. They do not do photosynthesis. ● Is it likely a rhodophyte? Yes! These are the red algae, and they have all these characteristics. ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Did Version 1
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you recall that phycoerythrins and phycocyanins are red pigments? Did you remember the name of the red algae? ● This question asked you to identify the protist. 47) A 48) A 49) A 50) A 51) kinetoplastids 52) Alveolata 53) parasites
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Chapter 29 13e MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 1) Cooksonia is a genus of very early tracheophyte plants. Unlike modern tracheophytes they only grew to a few centimeters in height. What feature provides the best explanation for their diminutive size? A) They completely lacked vascular tissues. B) They did not have stomata. C) They consisted of only photosynthetic stems, not roots or leaves. D) Cooksonia species were not autotrophic.
2)
Why is a rhizoid not considered a true root? A) Rhizoids lack the capacity to anchor mosses into the substrate. B) Rhizoids are not capable of absorbing water. C) True roots have mycorrhizal fungi. D) Rhizoids lack xylem tissue. E) Only true roots are capable of nitrogen fixation.
3) Azolla filiculoides is a small aquatic fern that is typically 1-2 cm tall. How would a botanist distinguish it from a bryophyte? A) It produces seeds. B) It has xylem tissue. C) It has a gametophyte. D) It has chloroplasts.
4) Hepaticophytes lack stomata and tracheids. What would provide evidence to justify their inclusion in the Bryophytes and not the Charophytes?
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A) Cellulose in theircell walls B) Male gametes produced in antheridia C) The use ofchlorophyll D) A haplodiplonticlifecycle
5)
The aquatic ancestry of bryophytes is most clearly demonstrated by what character? A) the use offlagellated motile sperm B) mycorrhizalassociations with fungi C) a nutritionallydependent sporophyte D) the production of a sporangium
6)
Why are most bryophytes less than 10 cm tall? A) They have underdeveloped stomata. B) They are seedless. C) They lack a cuticle. D) The have conducting cells instead of tracheids. E) They have no H2O transport mechanisms.
7)
The development of tracheids helped land plants to A) resist desiccation. B) protect the genome from UV exposure. C) grow to very large sizes. D) absorb H2O from stems and leaves. E) take in more CO2.
8)
What is a 15 meter tall tree fern?
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A) a gametophyte B) haploid C) produced bymeiosis D) a sporophyte
9)
Which of these organisms do not possess a cuticle? A) Charophytes B) Bryophytes C) Tracheophytes D) Club mosses E) Pterophytes
10)
A waxy cuticle prevents desiccation. What is the cost of this adaptation? A) Lowered lightabsorption B) Reduced gaspermeability C) SlowerH2O transport D) Increased exposureto damaging UV radiation E) Increased susceptibility to pathogenicinfection
11) Plants lacking well-developed conducting systems such as mosses, liverworts, and hornworts have been called A) gametophytes. B) sporophytes. C) angiosperms. D) gymnosperms. E) bryophytes.
12)
Which of the following represents a monophyletic group?
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A) mosses, liverworts, and hornworts B) ferns and club mosses C) ferns, whisk ferns, and horsetails D) liverworts and hornworts E) Charophytes and mosses
13) Which plants are characterized by a conducting system, the possession of cuticles, specialized stems, and roots, stomata, and, in many species, seeds? A) liverworts B) mosses C) tracheophyte D) horsetails E) club mosses
14)
Bryophytes, like ferns and certain other tracheophyte plants, require A) air to reproduce sexually. B) water to reproduce sexually. C) soil to reproduce sexually. D) shade to reproduce sexually. E) sunlight to reproduce sexually.
15) The colorless rootlike projections of mosses, liverworts, and hornworts, which anchor them to the substrate are called A) rhizoids. B) tap roots. C) fibrous roots. D) specialized roots. E) storage roots.
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16)
Plants and their predecessors, green algae, do not share the property of A) containing chlorophylls a and b, and carotenoids. B) containing cellulose-rich cell walls. C) containing a system of roots and stems. D) containing starch as the primary food storage product. E) forming a cell plate during cytokinesis.
17)
Well-developed vascular systems are absent in all of the following except A) mosses. B) liverworts. C) hornworts. D) Charophytes. E) Pterophytes.
18)
Survival on land for organisms is difficult because of the problem of A) desiccation. B) pollination. C) syngamy. D) spore germination. E) coevolution.
19)
Which of the following is not a characteristic of all tracheophytes? A) specialized conducting systems. B) waxy cuticle. C) stomata. D) roots. E) seeds.
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20) Plant success on the terrestrial landscape is linked to the evolution of all of the following except A) specialized roots. B) stems. C) specialized reproductive features. D) increased area for photosynthesis in the leaves. E) gas-filled air spaces.
21)
The dominant stage in the life cycle of tracheophyte plants is the A) epiphytegeneration. B) sporophyte generation. C) spore generation. D) gametophyte generation. E) angiosperm generation.
22) Plants as well as brown, green, and red algae show a basic life cycle which involves the alternation of generations between a(n) A) spore and pollen. B) megaspore and a microspore. C) seed and a cone. D) sporophyte and a gametophyte. E) egg and a sperm.
23)
The gametophyte is green and nutritionally independent in
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A) mosses, liverworts, and ferns. B) angiosperms. C) gymnosperms. D) tracheophytes. E) seed plants.
24)
To reproduce sexually, bryophytes require A) heterospory. B) free water external to the plant. C) high temperatures. D) solar energy. E) insect pollination.
25) Among the bryophytes, which of the following contain distinct stemlike axis, small leaves, and rootlike rhizoids? A) liverworts B) hornworts C) mosses D) algae E) cycads
26) Which of the following features are common to the photosynthetic structures of both mosses and club mosses? A) vascular strands B) chlorophyll a and b C) haploid cells D) only one cell thick except at midrib E) stomata
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27)
Hornworts differ from mosses and liverworts in containing A) small leaves. B) sporophytes. C) photosynthetic sporophytes. D) gametophytes. E) spores.
28)
In tracheophyte plants, water and dissolved minerals are conducted away from roots by A) water vessels. B) stomata. C) phloem tubes. D) xylem tubes. E) chloroplasts.
29)
The most abundant group of seedless tracheophyte plants are the A) club mosses. B) horse tails. C) angiosperms. D) ferns. E) gymnosperms.
30)
All of the following statements about ferns are correct except A) ferns flourish in many habitats, but the majority are located in the tropics. B) the sporophyte is a conspicuous generation. C) the gametophyte is a conspicuous generation. D) ferns have underground stems called rhizomes. E) sori are located on the back or ventral surface of fronds.
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31) A bryologist (a scientist that studies mosses, and their allies) gives a lecture to your biology class. In her lecture, she makes a reference to fern reproduction. She says, "Fern spores germinate into_________blank." A) gametophytes, which are often heart-shaped and have rhizoids that anchor the fern to the substrate B) gametophytes, which are often heart-shaped and have roots that anchor the fern to the substrate C) sporophytes, which are often heart-shaped and have rhizoids that anchor the fern to the substrate D) sporophytes, which are often heart-shaped and have roots that anchor the fern to the substrate
32) Whisk ferns, club mosses, and horsetails have all the following characteristics in common with ferns except A) all of these plants are seedless tracheophyte plants. B) all of these plants produce flagellated sperm. C) all of these plants form antheridia and archegonia. D) all of these plants require free water for the process of fertilization to occur. E) all of these plants have no vascular tissue.
33) Advances in molecular systematics show that whisk ferns and horsetails are the closest living relatives of A) mosses. B) club mosses. C) seed plants. D) gymnosperms. E) ferns.
34)
Which one of the following statements about haplodiplontic life cycles is false?
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A) For each gene, cells of the gametophyte stage have a single allele. B) Spore mother cells produce haploid spores by meiosis. C) The gametophyte stage produces gametes by mitosis. D) The zygote is the only diploid cell in the sporophyte stage. E) Mitosis occurs in both sporophyte and gametophyte stages.
35)
Which one of the following structures in the moss life cycle is not haploid? A) germinating spore B) antheridium C) sperm D) spore mother cell E) rhizoid tissue
36)
Which of the following groups is most closely related to the tracheophytes? A) Bryophytes B) Charophytes C) Rhodophytes D) Chlorophytes
37) For which of the following organisms is the sporophyte stage the dominant stage in the life cycle? A) charophyte B) fern C) green alga Chlamydomonas D) moss E) liverwort
38)
Which one of the following statements about a typical fern life cycle is false?
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A) Sori contain sporangia. B) Spores are haploid. C) Gametophytes have rhizomes. D) Gametes are produced by mitosis. E) The sporophyte grows out of an archegonium.
39) Which one of the following traits would be found in the sporophyte of a typical fern but not a moss? A) homospory B) tracheids C) gametophytes with rhizoids D) antheridia E) a sporophyte generation
40)
How do lycophytes differ from bryophytes? A) Lycophytes havetracheids. B) Lycophytes produceseeds. C) Lycophytes useflowers for reproduction. D) The dominant stage in a lycophyte is the gametophyte.
41) Giant kelp (Macrocystis pyrifera) is a large brown seaweed that grows in underwater assemblages in along the coast of California. Despite their size (they can grow up to 60 m in length) and their importance as producers and habitat in kelp forests, these organisms are considered algae.Which of the following true statements about kelp would explain why they are not classified as plants?
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A) The absence of a cuticle enables the kelp blades to absorb water directly over their entire surface. B) The kelp life cycle involves a diploid sporophyte and a haploid gametophyte. C) Kelp gametangia produce flagellated sperm as part of the sexual life cycle. D) Kelp holdfasts anchor the body (thallus), but they do not contain vascular tissue. E) Kelp chloroplasts contain the photosynthetic pigment chlorophyll a.
42) Which of the following true statements about humans tell you that we do not have a haplodiplontic life cycle? A) Sperm are created by meiosis in the testes. B) As a baby grows into an adult, new cells are added by mitosis. C) The human body is composed of many diploid cells. D) A human zygote is formed by fusion of a sperm and an egg from different parents.
43) Which of the following would allow you to distinguish between a liverwort and a hornwort? A) The ploidy of the photosynthesizing body. B) The presence of an archegonium. C) The presence of tracheids. D) The presence of a multicellular gametophyte. E) Possession of a cuticle.
44) A horsetail gametophyte looks like a lobed liverwort gametophyte. What evidence in the horsetail sporophyte tells us horsetails are not bryophytes? A) A horsetail sporophyte has tracheids. B) A horsetail sporophyte has sporangia that produce haploid spores. C) A horsetail sporophyte is diploid. D) A horsetail sporophyte is the product of fertilization of an egg by a flagellated sperm. E) A horsetail sporophyte grows by mitosis from a zygote.
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45) Club mosses are sometimes called ground pines because their sporophytes resemble tiny pine trees. Which of the following provides evidence that ground pines are not seed plants? A) Ground pines conduct photosynthesis using lycophylls. B) Ground pines have a sporophyte dominant life cycle. C) Ground pine leaves are covered with a cuticle. D) Ground pines have tracheids. E) Ground pines produce haploid spores by meiosis.
FILL IN THE BLANK. Write the word or phrase that best completes each statement or answers the question. 46) The first plants clearly evolved from an organism that, if it existed today, would be classified as a multicellular green_________blank.
47) Plants have a_________blank life cycle in which the haploid and diploid stages are multicellular.
48)
In plants, the sporophyte generation produces_________blank as a result of meiosis.
49) In all seed plants, male and female_________blank develop within the parent sporophyte and are completely dependent on it for nutrition and water.
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Answer Key Test name: Chap 29_13e_Raven 1) C
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Clarify Question What is the key concept addressed by the question? ● The concept addressed by this question is the benefit of the smaller stature of Cooksonia. What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to the features that contribute to the smaller size of Cooksonia. Gather Content What do you already know about Cooksonia? What other information is related to the question? ● Cooksonia is the first known vascular land plant. ● Cooksonia is now extinct. ● Little competition existed for Cooksonia. ● Roots and leaves were absent from Cooksonia. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Cooksonia was a tracheophyte, so it did have vascular tissue. ● Photosynthesis was utilized by Cooksonia, and some members of this genus did have stomata that were likely utilized for gas exchange. ● Since Cooksonia lacked roots, taller stature would not be possible. Since it lacked leaves, and competition was low, photosynthesis could occur on the stem of Cooksonia. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use Cooksonia in a new situation. If you got an incorrect answer, did you remember that Cooksonia lacked roots and leaves, or that there was little Version 1
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competition for space in the habitat of Cooksonia? Did you have trouble extending the features of Cooksonia to determine the correct answer? 2) D
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Clarify Question What is the key concept addressed by the question? ● The concept addressed here is the nature of a true root. What type of thinking is required? ● This question is asking you to compare and contrast rhizoids with true roots, making it an evaluate-level question. Gather Content What do you already know about true roots and rhizoids? What other information is related to the question? ● Rhizoids are root-like structures in that they anchor the mosses and other plants that possess them. ● While roots are multicellular tissues, rhizoids are unicellular and therefore are not tissues. ● Roots contain vascular tissue. ● Unlike roots, rhizoids lack vascular tissue. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Rhizoids do anchor mosses to the substrate. ● Although they do not have vascular tissue, rhizoids can conduct water. ● Roots do not fix nitrogen; it is the symbiotic bacteria associated with roots that fix nitrogen. ● Since true toots have vascular tissue, and vascular tissue is contains xylem, if a plant lacks xylem, it stands to reason that it does not have true roots. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to weigh Version 1
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and judge, or evaluate, true roots and rhizoids. If you got an incorrect answer, did you remember that rhizoids differ from true roots by lacking vascular tissue, or the criteria to compare rhizoids and true roots includes the shared function of anchoring the plant? Did you have trouble weighing the merits of rhizoids relative to true roots to determine the correct answer? 3) B
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Clarify Question What is the key concept addressed by the question? ● This question is highlighting the differences between ferns and bryophytes. What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to the identification of a fern versus a bryophyte. Gather Content What do you already know about ferns and bryophytes? What other information is related to the question? ● Bryophytes include mosses, liverworts, and hornworts. ● Bryophytes lack vascular tissue. ● Ferns are vascular plants. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Both bryophytes and ferns have gametophytes and chloroplasts, so those features could not be used to distinguish between the two plants. ● Ferns and bryophytes reproduce by spores, not seeds, so this is also not a characteristic that is relevant. ● A key factor that differentiates bryophytes and ferns is the presence of vascular tissue in ferns. This is absent in bryophytes. Since xylem is a component of vascular tissue, it could be used to differentiate a fern from a bryophyte. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use ferns and bryophytes in a new situation. If you got an incorrect answer, Version 1
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did you remember that vascular tissue includes xylem, or that ferns have vascular tissue but bryophytes do not have vascular tissue? Did you have trouble extending the characteristics of ferns and bryophytes to determine the correct answer? 4) B
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Clarify Question What is the key concept addressed by the question? ● This question is asking about the factor that would differentiate a hepaticophyte from a bryophyte. What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to the characteristics of hepaticophytes. Gather Content What do you already know about hepaticophytes? What other information is related to the question? ● Charophytes are green algae that live in fresh water. ● Hepaticophytes are commonly known as liverworts. ● Liverworts are part of a larger group known as bryophytes. ● Bryophytes lack vascular tissue, but can exist on land in various environments. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● The presence of cellulose in the cell wall, the use of chloroplasts, and the haplodiplontic life cycle are features that are common to charophytes and hepaticophytes, so these feature would not allow differentiation. ● Antheridia (and archegonia) produce gametes and provide a protective chamber to keep them from drying out. Since liverworts exist on land and charophytes do not, this would be a key factor in their differentiation. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to apply Version 1
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the characteristics of hepaticophytes in a new situation. If you got an incorrect answer, did you remember that hepaticophytes are vascular, land plants, or that antheridia are an adaptation of land plants? Did you have trouble extending hepaticophytes to determine the correct answer? 5) A 6) D
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Clarify Question What is the key concept addressed by the question? ● The key concept addressed here is the limiting factor for bryophyte size. What type of thinking is required? ● This question is asking you to weigh and judge, or evaluate, sizelimiting features of bryophytes. Gather Content What do you already know about bryophytes? What other information is related to the question? ● Bryophytes include mosses, liverworts, and hornworts. ● Although they are found in a variety of environments, most bryophytes are found in moist habitats. ● Bryophytes lack vascular tissues. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● The lack of seeds in bryophytes does not limit their size. ● Mosses may have stomata at certain life stages, but bryophytes overall do not possess stomata. ● Bryophytes do possess water-conducting tissues, but they lack tracheids and vascular tissues. Since vascular tissues increase the efficiency of water and nutrient circulation, they make tall heights possible for plants. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to weigh and judge, or evaluate, bryophytes and the size-limitations that are Version 1
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relevant for them. If you got an incorrect answer, did you remember that bryophytes lack vascular tissue, or that vascular tissue includes tracheids, which facilitate the efficient delivery of water in plants? Did you have trouble weighing the merits of internal structure relative to plant size to determine the correct answer? 7) C
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Clarify Question What is the key concept addressed by the question? ● This question is asking you to apply the benefits of tracheids to land plant adaptations. What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to the advantages conferred by tracheids. Gather Content What do you already know about tracheids? What other information is related to the question? ● Tracheids are the first known components of vascular tissues. ● Vascular tissues are used to move water and other nutrients efficiently within a plant. ● Water and nutrients are necessary for a plant to maintain its structure and metabolic activities. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Although they move materials including water within a plant, tracheids do not prevent desiccation, nor are they protective against UV exposure. ● Tracheids deliver water to leaves and stems rather than absorbing it from same. ● Tracheids are passages for delivery of materials; they do not take in CO2. ● Since tracheids increase the efficiency of water and nutrient circulation, they make large sizes possible for plants. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use tracheids in a new situation. If you got an incorrect answer, did you remember that tracheids are components of vascular tissue, or that vascular tissue is used to efficiently transport water and nutrients? Did you have trouble extending tracheids to determine the correct answer? 8) D
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Clarify Question What is the key concept addressed by the question? ● The question is asking about the nature of a fern that reaches a large size. What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to determine the identity of a very large fern. Gather Content What do you already know about ferns? What other information is related to the question? ● The sporophyte is the dominant life stage of the fern. ● Sporophytes are diploid. ● Fern sporophytes have vascular tissues, but fern gametophytes do not have vascular tissues. ● Gametophytes are haploid. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Since fern gametophytes lack vascular tissues, they remain very small, so this answer can be excluded. ● Gametophytes but not sporophytes, are haploid, so this answer can also be excluded. ● Gametes are produced by meiosis, so this answer can be disregarded. ● Sporophytes possess vascular tissue and can thereby grow to very large sizes. 15 meters is within an expected size for the sporophyte of a tree fern. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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● Answering this question correctly depended on your ability to use fern life stages in a new situation. If you got an incorrect answer, did you remember that ferns can exist as sporophytes and gametophytes, or that sporophytes alone can grow to large sizes? Did you have trouble extending fern life stages to determine the correct answer? 9) A 10) B 11) E 12) C
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Clarify Question What is the key concept addressed by the question? ● This question is asking you to determine which group of plants is most closely related. What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to the analysis of the evolutionary history of plants. Gather Content What do you already know about phylogeny? What other information is related to the question? ● Phylogeny refers to the evolutionary history of different species. ● Information to build an evolutionary history of different species can be drawn from morphology, cytology, nucleic acid analysis, and other sources. ● A proposed evolutionary history can be diagrammed on a cladogram, which shows the relatedness of species. ● A monophyletic relationship shows the closest evolutionary relatedness. ● A monophyletic grouping includes a common ancestor and all descendant species. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● If a cladogram is examined, it is clear that the horsetails, ferns, and whisk ferns share a common ancestor. There are no descendant species from that common ancestor that are not included int his group. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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● Answering this question correctly depended on your ability to use phylogeny in a new situation. If you got an incorrect answer, did you remember that a monophyletic group includes species that share a common ancestor, or that a monophyletic grouping must include all descendant species from the common ancestor? Did you have trouble extending phylogeny to determine the correct answer? 13) C 14) B 15) A 16) C 17) E 18) A 19) E 20) E 21) B 22) D 23) A 24) B 25) C 26) B
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Clarify Question What is the key concept addressed by the question? ● This question is asking you to identify features that are possessed by both mosses and club mosses. What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to the similarities between mosses and club mosses. Gather Content What do you already know about mosses and club mosses? What other information is related to the question? ● Mosses and club mosses are both land plants. Mosses are bryophytes, and club mosses are lycophytes. ● Mosses and plants with true leaves undergo photosynthesis, which requires pigments to absorb light. ● The main photosynthetic pigments are chlorophyll a and chlorophyll b. ● Mosses do not have vascular tissue, but club mosses have true leaves that do have vascular tissue. ● The leaf-like structures of mosses are one cell thick, while true leaves have many cell layers. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● While true leaves do have vascular strands, mosses do not have vascular strands. ● True leaves have multiple cell layers, so this answer can be disregarded. ● While mosses may have stomata in the capsule portion of the sporophyte, stomata are not present in the leaf-like structures that mosses possess. Version 1
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● Since mosses and club mosses undergo photosynthesis, they both possess chlorophyll a and chlorophyll b. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use mosses and club mosses in a new situation. If you got an incorrect answer, did you remember that true leaves are multicellular and have vascular tissue, or that both mosses and club mosses are photosynthetic? Did you have trouble comparing bryophytes and lycophytes to determine the correct answer? 27) C 28) D 29) D 30) C 31) A 32) E 33) E 34) D 35) D 36) A 37) B 38) C 39) B 40) A 41) A
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Clarify Question What is the key concept addressed by the question? Why aren’t large algae classified as plant? What type of thinking is required? This question is asking you to identify key factors that qualify something as a land plant. Gather Content What do you already know about land plants? What other information is related to the question? Land plants share certain characteristics with green, red, and brown algae, including the presence of chlorophyll a and a haplodiplontic life cycle. All land plants have a number of key adaptations to living on land that algae do not have, such as the presence of a cuticle and the presence of a multicellular embryo. Additional adaptations to living on land, such as stomata, vascular tissue, unflagellated sperm, pollen, fruit, and flowers are important, but are not shared by all land plants (so the lack of these adaptations cannot be used to determine an organism is not a land plant). Choose Answer Given what you now know, what information is most likely to produce the correct answer? Plants are protected from drying out by a waxy cuticle that is relatively impermeable, preventing water loss but also limiting gas exchange. The lack of a cuticle may be an advantage for kelp in an aqueous environment, but it means that kelp cannot live outside the water and allows us to determine that kelp is not a land plant. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you Version 1
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revise your approach to produce a more desirable result? Answering this question correctly depended not only on distinguishing between kelp and land plants, but on your ability to break down, or analyze, the key features that unite all land plants… If you got an incorrect answer, did you remember that land plants share certain features (like chlorophyll a and a haplodiplontic life cycle) with many algae, or that some adaptations (like vascular tissue and unflagellated sperm) are not shared by all land plants? Did you have trouble comparing kelp to the bryophytes (rather than tracheophytes) to determine the correct answer? 42) A
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Clarify Question What is the key concept addressed by the question? How is a diplontic life cycle different from a haplodiplontic life cycle? What type of thinking is required? You are being asked to take what you already know and use, or apply, it to compare human and plant life cycles. Gather Content What do you already know about the haplodiplontic life cycle? What other information is related to the question? Plants have a haplodiplontic life cycle that features two body forms: a multicellular diploid sporophyte and a multicellular haploid gametophyte. The haploid gametophyte produces haploid gametes by mitosis. A sporophyte is formed by the fusion of a sperm and an egg, and then the diploid sporophyte produces haploid spores by meiosis. Both the gametophyte and sporophyte grow by mitosis. Choose Answer Given what you now know, what information is most likely to produce the correct answer? Humans and other animals have a diplontic life cycle, in which gametes are formed by meiosis from diploid cells. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Answering this question correctly depended on your ability to use your understanding of the haplodiplontic life cycle in a new situation. If you got an incorrect answer, did you remember that gametes are formed by the haploid gametophyte by plants, which means the process must be mitosis? Did you recognize that the sporophyte is also a diploid body Version 1
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formed that grows by mitosis from a diploid zygote? Did you have trouble extending your knowledge of humans to the plant life cycle to determine the correct answer? 43) A
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Clarify Question What is the key concept addressed by the question? How are liverworts different from hornworts? What type of thinking is required? This question is asking you to compare and contrast liverworts and hornworts, making it an evaluate-level question. Gather Content What do you already know about liverworts and hornworts? What other information is related to the question? Liverworts and hornworts are two types of bryophytes. All land plants feature a haplodiplontic life cycle with a multicellular gametophyte, a cuticle, and archegonia. Neither liverworts nor hornworts have vascular tissue. Hornworts have a photosynthetic sporophyte, whereas liverworts rely on the gametophyte for photosynthesis. Choose Answer Given what you now know, what information is most likely to produce the correct answer? The presence of a diploid photosynthesizing body would let you know that you are not looking at a liverwort. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Answering this question correctly depended on your ability to weight and judge, or evaluate, the differences between liverworts and hornworts. If you got an incorrect answer, did you remember that liverworts and hornworts differ by the hornwort sporophyte’s ability to conduct photosynthesis? Did you recognize that ploidy was referring to the sporophytes and gametophytes? Did you have trouble comparing and Version 1
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contrasting the two types of bryophytes to determine the correct answer? 44) A
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Clarify Question What is the key concept addressed by the question? How is a horsetail sporophyte different from a bryophyte sporophyte? What type of thinking is required? This question is asking you to compare and contrast horsetail and bryophyte sporophytes, making it an evaluate-level question. Gather Content What do you already know about horsetail and bryophyte sporophytes? What other information is related to the question? Bryophytes are gametophyte dominant plants. The sporophytes are reliant on the gametophytes for nutrition, although in the hornworts the sporophyte is capable of photosynthesis. Horsetails are pterophytes, a group of tracheophytes. They are sporophyte dominant plants featuring a photosynthetic sporophyte with vascular tissue. Both bryophytes and pterophytes have a haplodiplontic life cycle. Choose Answer Given what you now know, what information is most likely to produce the correct answer? The key difference between horsetails and bryophytes is the presence of tracheids. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Answering this question correctly depended on your ability to weight and judge, or evaluate, bryophytes and lycophytes. If you got an incorrect answer, did you remember that even though bryophytes are gametophyte dominant plants, they still have multicellular sporophytes that grow from a zygote and produce spores? Did you recall that Version 1
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horsetails are pterophytes, which are vascular plants? Did you have trouble comparing bryophytes to pterophytes to determine the correct answer? 45) A
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Clarify Question What is the key concept addressed by the question? How do lycophytes compare to other tracheophytes? What type of thinking is required? This question is asking you to compare and contrast lycophytes with conifers, making it an evaluate-level question. Gather Content What do you already know about lycophytes and conifers? What other information is related to the question? Lycophytes are tracheophytes, but they are the sister group to the other taxa of vascular plants. All tracheophytes have a dominant sporophyte, vascular tissue, stems, roots, and leaves. Leaves evolved independently in the lycophyte lineage, so that lycophytes bear lycophylls with a single unbranched vein, while pterophytes and seed plants instead evolved euphylls with branching vascular tissue. Choose Answer Given what you now know, what information is most likely to produce the correct answer? Ground pines are lycophytes, bearing lycophylls instead of euphylls. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Answering this question correctly depended on your ability compare and contrast lycophytes with seed plants. If you got an incorrect answer, did you remember club mosses and seed plants are both tracheophytes, or that as the sister group to the other tracheophytes lycophytes evolved different leaves called lycophylls? Did you have trouble ruling out the Version 1
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life cycle similarities shared by all tracheophytes to determine the correct answer? 46) algae 47) haplodiplontic 48) spores 49) gametophytes
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Chapter 30 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) Drupes have multiple seeds and fused carpels. ⊚ ⊚
true false
2) Germination inhibitors that must be digested by acids in order to be removed help to ensure the seed will be dispersed with some fertilizer. ⊚ ⊚
3)
true false
As the endosperm matures it swells and eventually becomes the fruit. ⊚ true ⊚ false
4) Pollination and fertilization are essentially the same process. If pollination occurs, fertilization will follow quickly. ⊚ ⊚
true false
5) After fertilization, the zygote continuously develops until an embryonic plant is formed within the seed. ⊚ ⊚
6)
true false
All gymnosperms have needle-like leaves and produce some type of resin. ⊚ true ⊚ false
7) In seed plants, the sporophyte has been greatly reduced in size and is typically just a few cells. Version 1
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⊚ ⊚
8)
true false
In seed plants, the entire male gametophyte is transported to the female. ⊚ ⊚
true false
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 9) Children in the Southeastern United States play with red maple fruits ( Acer rubrum). The fruits are tossed in the air and spin back to the ground, acting like small helicopters. Which part of the fruit allows for this? A) The pericarp B) The integument C) The endosperm D) The ovule
10)
Are any of these vegetables actually fruit? A) Sugar beets B) Corn C) Carrots D) Celery E) All of these are vegetables, none of them are fruit.
11)
Fruits derived from which structure?
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A) styles B) ovaries C) stigmas D) anthers E) filaments
12)
Antipodals and synergids are A) produced in the female gametophyte. B) the result of double fertilization. C) what will fuse to form the endosperm. D) responsible for pollen tube formation. E) nonfunctional vestigial structures.
13)
The mature male gametophyte is produced A) in the anther. B) within the pollen granule during transfer. C) when the pollen makes contact with the stigma. D) in the pollen tube when the generative cell divides. E) within the ovule just prior to fertilization.
14)
Double fertilization occurs when A) the sperm and tube nuclei fertilize the egg. B) two sperm cells fertilize the two polar nuclei. C) one sperm fuses with the egg and the other sperm fuses with both polar nuclei. D) the polar nuclei fuse with the egg after it has fused with the sperm.
15)
Petals
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A) protect the developing flower. B) enclose and protect the ovule. C) produce pollen. D) are part of the gametophyte. E) attract pollinators.
16)
The breakdown of antipodals A) is a normal part of development in the ovule. B) would result in a seed without a seed coat. C) would produce an ovule with no egg cell. D) would cause a failure in endosperm development.
17) A botanist examines two plants. Plant A has large colorful petals; plant B has extremely tiny white flowers. Which one is most likely animal pollinated? A) Plant A B) Plant B
18)
Pollen comes from the A) carpel. B) petal. C) stigma. D) anther. E) style.
19) Double fertilization produces a _________blank embryo and a _________blank endosperm.
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A) haploid; diploid B) diploid; haploid C) diploid; triploid D) triploid; diploid E) haploid; triploid
20)
Based on the outcome for plants, a monkey eating a banana is a A) pollinator. B) fertilizer. C) disperser. D) parasite.
21)
What is the function of the generative cell in conifers? A) Growth of themegaspore B) Dispersal of thepollen C) Production of thearchegonium D) Formation of thesperm E) Maturation of thefemale cone
22)
Ephedrine is a stimulant that is derived from a member of the phylum A) Hepaticophyta. B) Gnetophyta. C) Pterophyta. D) Cycadophyta.
23)
A fruit-bearing dioecious flower would have
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A) an androecium. B) a gynoecium. C) both an androecium and a gynoecium. D) neither an androecium nor a gynoecium.
24)
Why is external water not essential for fertilization in seed plants? A) The sperm cells in seed plants are capable of resisting desiccation. B) Seed plants use pollen instead of sperm for fertilization. C) Pollen grains are transported by wind or an animal. D) Sperm cells are used to transport pollen to the archegonia. E) Ovules are contained within the pollen.
25)
Which part of the seed is responsible for providing nutrition to the embryo? A) Integument B) Endosperm C) Cotelydons D) Seed coat E) Procambium
26)
What does it mean if a plant is dioecious? A) There is double fertilization of the embryo. B) Pollination and fertilization are separate events. C) There are separate male and female sporophytes. D) The sporophyte and the gametophyte are on the same plant.
27)
Pollen tubes
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A) transport pollen to the stigma. B) facilitate the growth of pollen. C) package sperm into pollen granules. D) allow sperm to fertilize the egg. E) are present during spermatogenesis.
28) Due to their pinnately compound leaves, tropical habitat, and overall appearance members of which phylum are often thought of as a type of palm? A) Coniferophyta B) Gnetophyta C) Cycadophyta D) Ginkophyta
29)
What is the function of pine resins? A) transportation of sucrose to the roots B) reduction of fungal and insect parasitism C) triggering of seed maturation D) aiding in pollen dispersal
30) Old pine stumps are dug up, split into pieces and sold as "fatwood." Fatwood is used as a fire starter. Why is this done? A) The wood in the stumps is porous and dry, thus it burns easily. B) The high concentration of volatile organic compounds makes the wood flammable. C) Pine bark does not absorb water and is flammable.
31)
What happens to the ovary after fertilization in angiosperms?
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A) It dies. B) It forms the seed coat. C) It becomes food for the embryo inside the seed. D) It becomes the fruit.
32)
Why are conifers and cycads considered gymnosperms?
A) They have true vascular tissue but do not form seeds. B) The female gametophyte is not completely enclosed in sporophyte tissue at the time of pollination. C) The fruit is not fleshy. D) The pollen is wind-dispersed. E) Pollination and fertilization occur at different times.
33) A researcher brings a sample of dry soil to the lab, wets it, provides ample amounts of fertilizer, and places the soil in a container in a greenhouse. Which type of plant would be least likely to emerge? A) Pine seedling B) Sunflower C) Corn D) Wheat E) Liverwort
34)
The seed coat is formed by the hardening of the A) ovule. B) integument. C) endosperm. D) embryo. E) prothallus.
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35)
Based on the number of species, the most successful extant phylum of plants is the A) Anthophyta. B) Coniferophyta. C) Pterophyta. D) Gnetophyta. E) Charophyta. F) Hepaticophyta.
36)
Why can corn seeds germinate in total darkness?
A) The seed coating absorbs water. B) Seeds are heterotrophic and can capture nutrients from the soil. C) The endosperm provides the embryo with the nutrition needed during the initial germination stages. D) Soil microbes degrade the seed coating allowing the seed to germinate.
37)
Why aren't ferns commonly found in deserts? A) Fern fronds are sensitive to UV light. B) Fern spores are unable to resist prolonged dry conditions. C) Ferns are nonvascular and cannot absorb water from deep within the soil. D) Fern pollen is spread by insects that do not occur in deserts.
38) Malik discovers a plant while out on a walk. The leaves have vascular tissue, so it is clearly a tracheophyte, but he would like to narrow it down more. After further study, Malik observes that the plant has non-flagellated sperm, a seed that develops in an exposed ovule, and possess both vessels and tracheids. Based on this information, this plant is most likely a member of which phylum?
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A) Phylum Gnetophyta B) Phylum Anthophyta C) Phylum Cycadophyta D) Phylum Coniferophyta E) Phylum Ginkgophyta
39) Cucumis sativus is a creeping vine native to Southeast Asia. Today it is cultivated around the world for its fruit, called cucumbers. After double fertilization has occurred, three carpels (each containing multiple ovules) will fuse and elongate into a cucumber with high water content and a thin skin. When mature, the entire cucumber (skin, pericarp, and seeds) are often sliced and eaten raw in salads. Based on this information, what type of structure is a cucumber? A) Berry B) Drupe C) Legume D) Samara E) Stem
40) Orange trees,Citrus sinensis, are known for their white flowers (the orange blossom is the state flower of Florida) and orange fruit. Which of the following correctly describes an event that occurs during orange tree reproduction? A) A generative cell produces sperm by mitosis. B) A pollen grain fuses with an egg to form a zygote. C) A sperm fuses with both antipodals to form endosperm. D) A megaspore mother cell divides by meiosis to form four pollen grains. E) The female gametophyte divides by mitosis to form an egg and a synergid.
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Answer Key Test name: Chap 30_13e_Raven 1) FALSE 2) TRUE
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Clarify Question What is the key concept addressed by the question? ● This question is asking about the nature of germination inhibitors. What type of thinking is required? ● Apply level:● You are being asked to take what you already know and use, or apply, it to germination inhibitors and the conditions that optimize their use. Gather Content What do you already know about germination? What other information is related to the question? ● Seeds can become dormant until environmental conditions are conducive to growth. ● Germination will not occur until the seed has water and oxygen. ● Other more species-specific factors can also be necessary for germination. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Acids are necessary to deactivate the germination inhibitors that are found in the seed coats of some species. ● The acids in the gastrointestinal tract of animals that disperse seeds can serve to deactivate germination inhibitors. ● If germination is activated as a seed passes through the gut of animal, as the seed is excreted, the waste that accompanies it would serve as fertilizer. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● Answering this question correctly depended on your ability to use germination in a new situation. If you got an incorrect answer, did you remember that inhibitors can prevent germination in less than ideal conditions, or that acids may inactivate germination inhibitors? Did you have trouble extending the process of germination to determine the correct answer? 3) FALSE 4) FALSE Pollination and fertilization are different processes that may be separated by a long delay. Pollination is the mechanical transfer of pollen from its source to a receptive area on the receiving plant. Sperm are subsequently conducted to the egg by a pollen tube, and fertilization – the joining of sperm with egg – may occur much later. For instance, in a typical pine tree fertilization follows 15 months after pollination. 5) FALSE 6) FALSE 7) FALSE 8) TRUE 9) A
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Clarify Question What is the key concept addressed by the question?● The key concept addressed here is the structure and function of red maple seeds and fruit. What type of thinking is required?● Apply level:● You are being asked to take what you already know and use, or apply, it to the anatomy of the fruit of a red maple tree. Gather Content What do you already know about maple fruits? What other information is related to the question?● The ovary wall, or pericarp, consists of three layers; the exocarp, mesocarp, and endocarp. ● The pericarp gives rise to the fruit. ● Maples make fruits known as samaras. ● Samaras form wings from the outer tissues. Choose Answer Given what you now know, what information is most likely to produce the correct answer?● The integument hardens to produce the seed coat, which immediately surround the embryo. They would not act like helicopter blades. ● The endosperm is a nutritive layer also surrounds the embryo. It would not extend as wings. ● The pericarp is tissue that can be modified into various fruit parts, including the blade-like extensions of maple fruits. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level:● Answering this question correctly depended on your ability to use maple fruits in a new situation. If you got an incorrect answer, did you remember that pericarp forms fruits, or that can it take on different forms? Did you have trouble extending the characteristics of maple fruit Version 1
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to determine the correct answer? 10) B
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Clarify Question ● What is the key concept addressed by the question?● The key concept addressed here is the difference between vegetables and fruit. ● What type of thinking is required?● This question is asking you to compare and contrast fruit and vegetables, making it an evaluate-level question. Gather Content ● What do you already know about fruit? What other information is related to the question?● Fruits are the mature ovaries of angiosperms. Fruits usually contain seeds. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● Sugar beets, carrots, and celery are all vegetative structures. They are not fruit because they are not mature ovarian structures. ● Corn does represent a mature ovary, so it is considered to be a fruit. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Evaluate level:● Answering this question correctly depended on your ability to weigh and judge, or evaluate, fruits and vegetables. If you got an incorrect answer, did you remember that fruit differs from vegetables because it is a mature ovary, or the criteria to compare fruits and vegetables includes the origin of the fruit or vegetable? Did you have trouble distinguishing fruits relative to vegetables to determine the correct answer? Version 1
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11) B 12) A 13) D 14) C 15) E 16) A 17) A
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Clarify Question What is the key concept addressed by the question? ● The key concept addressed here is the nature of animal-pollinated plants. What type of thinking is required? ● Apply level:● You are being asked to take what you already know and use, or apply, it to the comparison of animal pollinated versus other plants. Gather Content What do you already know about animal-pollinated plants? What other information is related to the question? ● Animal-pollinated plants tend to be colorful and showy. ● Wind-pollinated plants may have no petals at all. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Plant B’s small, white flowers would not be attractive to animal pollinators. ● Since animal-pollinated plants have colorful flowers, plant A is the likely candidate for an animal-pollinated plant. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● Answering this question correctly depended on your Version 1
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ability to use pollination in a new situation. If you got an incorrect answer, did you remember that animal-pollinated plants have colorful flowers, or that wind-pollinated plants may have no petals? Did you have trouble recognizing different pollination characteristics to determine the correct answer? 18) D 19) C 20) C
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Clarify Question What is the key concept addressed by the question? ● This question is asking about the role of an animal who eats fruit in the lifecycle of the plant that made the fruit. What type of thinking is required? ● Apply level:● You are being asked to take what you already know and use, or apply, it to the function of fruit. Gather Content What do you already know about fruit? What other information is related to the question? ● Fruit represents the mature ovary of a plant. ● Fruit usually contains seeds. ● Seeds are the products of fertilization. ● Animals that consume fruit play a role in the lifecycle of the plant. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Since seeds are the products of fertilization, and fertilization happens after pollination, pollination and fertilization can be excluded as functions of the consumption of seeds. ● Parasites feed on the body fluids of the host. A banana is a product of a plant, not part of its body, so a monkey that feeds on a banana is not a parasite. ● By consuming a banana, a monkey disperses the seeds as it passes them along with waste from its body. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● Answering this question correctly depended on your ability to use fruit in a new situation. If you got an incorrect answer, did you remember that fruit often contains seeds, or that seeds from consumed fruit pass with waste from an animal’s body? Did you have trouble extending the definition of fruit to determine the correct answer? 21) D 22) B 23) B
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Clarify Question What is the key concept addressed by the question? ● The key concept addressed here is the composition of a fruit-bearing dioecious flower. ● Apply level:● You are being asked to take what you already know and use, or apply, it to the nature of a plant that produces fruit. Gather Content What do you already know about fruit? What other information is related to the question? ● Dioecious species have separate male and female individuals. ● In plants, the androecium is a male reproductive structure. ● The gynoecium is the female reproductive structure. ● Female reproductive structures include the ovaries. ● Mature ovaries become fruits in angiosperms. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Since the plant in question is dioecious, it must be male or female, but not both. ● Fruit is listed as a product of this plant, so the plant must be female. ● Since female plants possess gynoecia, this is the correct answer. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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● Apply level:● Answering this question correctly depended on your ability to use fruit in a new situation. If you got an incorrect answer, did you remember that fruit is produced by the female component of a plant, or that dioecious species have separate males and females? Did you have trouble extending the definition of fruit to determine the correct answer? 24) C 25) B 26) C 27) D 28) C 29) B 30) B
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Clarify Question What is the key concept addressed by the question? ● This question is asking about the logic of using old pine stumps as fire starters. What type of thinking is required? ● Apply level:● You are being asked to take what you already know and use, or apply, it to the reason for the flammability of fat wood. Gather Content What do you already know about pine? What other information is related to the question? ● The resin from certain pines can yield turpentine, which is a volatile liquid. ● Turpentine is a flammable compound. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Pine bark is fire resistant, so that answer can be ruled out. ● Stumps are generally the last section of a tree to dry out, so that answer can be excluded. ● Since turpentine is flammable and since it is present in the resin of pine, old pine trunks would be good fire starters because of the presence of this volatile organic compound. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? ● Apply level:● Answering this question correctly depended on your ability to use pine in a new situation. If you got an incorrect answer, did you remember that pine resin contains turpentine, or that turpentine is flammable? Did you have trouble extending the components of pine to determine the correct answer? 31) D 32) B 33) E
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Clarify Question What is the key concept addressed by the question? ● This question is asking about the likelihood of the emergence of various plant types from dry soil. What type of thinking is required? ● Apply level:● You are being asked to take what you already know and use, or apply, it to the propagation of different types of plants. Gather Content What do you already know about plant propagation? What other information is related to the question? ● Liverworts are bryophytes, which is a group that includes the mosses. ● Mosses require water to reproduce. ● Pines are gymnosperms, and they place their seeds in cones. They do not require water to reproduce. ● Sunflower, corn, and wheat are angiosperms. As seed plants, they do not require water to reproduce. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● As seed plants, pines, corn, wheat, and sunflowers could all have seeds in the dry soil that would germinate if sufficient levels of light and water were present. ● Since liverworts are bryophytes, they must have water to reproduce. Young would not form in dry soil, and since adults are not present in the dry soil, these plants would not appear. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● Answering this question correctly depended on your ability to use plant propagation in a new situation. If you got an incorrect answer, did you remember that pines, corn, sunflowers, and wheat are seed plants, or that liverworts require water to reproduce? Did you have trouble extending methods of plant propagation to determine the correct answer? 34) B 35) A 36) C
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Clarify Question What is the key concept addressed by the question? ● The key concept addressed here is the initial source of nutrients in corn seedlings. What type of thinking is required? ● Evaluate level:● This question is asking you to weigh and judge, or evaluate, the way that corn seedlings obtain nutrients without the presence of light. Gather Content What do you already know about corn seeds? What other information is related to the question? ● Flowering plants such as corn have extensive endosperm in their seeds. ● Endosperm is a source of nutrition for a plant embryo before its leaves emerge from the soil. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Soil microbes are not a key factor in the degradation of the seed coat and the germination of a seed. ● Seeds do not take in nutrients from the soil in significant amounts. ● Although seeds require water for germination, water does not provide nutrients for the growing plant. ● Since endosperm is abundant in corn seeds, and because it contains nutrients that are available to the growing plant, it is the endosperm that allow germination and growth to occur in the dark. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Evaluate level:● Answering this question correctly depended on your ability to weigh and judge, or evaluate, corn seeds and the nutrients that are available to them. If you got an incorrect answer, did you remember that endosperm is abundant in corn seeds, or that the endosperm is a nutrient source for newly-germinated corn seedlings? Did you have trouble weighing the merits of corn seeds relative to available nutrients to determine the correct answer? 37) B
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Clarify Question What is the key concept addressed by the question? ● This question is asking about the limitations of fern reproduction. What type of thinking is required? ● Apply level:● You are being asked to take what you already know and use, or apply, it to the exclusion of ferns from a desert habitat. Gather Content What do you already know about ferns? What other information is related to the question? ● Ferns require water for fertilization to occur. ● Ferns produce spores, which require a moist environment in which to grow. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Ferns are vascular plants, so that answer can be disregarded. ● Ferns do not produce flowers, so they do not produce pollen. ● Fern fronds do utilize UV light to drive photosynthesis. ● Since fern reproduction and spore growth is dependent on the presence of water, a dry environment such as a desert would not sustain a fern. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● Answering this question correctly depended on your Version 1
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ability to use ferns in a new situation. If you got an incorrect answer, did you remember that ferns require water to reproduce, or that fern spores also require moist environments? Did you have trouble extending the characteristics of ferns to determine the correct answer? 38) A
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Clarify Question What is the key concept addressed by the question? Can you identify a gymnosperm based on certain characteristics? What type of thinking is required? You are being asked to take what you already know and use, or apply, it to identify a plant that has a naked seed, non-flagellated sperm, and vessels. Gather Content What do you already know about seed plants? What other information is related to the question? Seed plants can be divided into gymnosperms (with naked seeds that develop in exposed ovules) and angiosperms (with seeds that develop inside fruit). Gymnosperms can be divided into four clades: conifers, cycads, gnetophytes, and Ginkgo. Cycads and Ginkgo have flagellated sperm, but conifers and gnetophytes do not. All gymnosperms have vascular tissue, but most have only tracheids. Only gnetophytes have vessels as well. Choose Answer Given what you now know, what information is most likely to produce the correct answer? The combination of characteristics tells Malik that this is a gnetophyte, since a conifer would not have vessels and an angiosperm would not have an exposed ovule. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Answering this question correctly depended on your ability to use your Version 1
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understanding of seed plants in a new situation. If you got an incorrect answer, did you remember that the fact that the seed develops in an expose ovule rules out angiosperms, or the presence of vessels rules out the other gymnosperms? Did you have trouble seeing that the three characteristics are only present in gnetophytes to determine the correct answer? 39) A
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Clarify Question What is the key concept addressed by the question? Can you identify a type of fruit based on its characteristics? What type of thinking is required? You are being asked to take what you already know and use, or apply, it to identify the type of fruit that is a cucumber. Gather Content What do you already know about fruit? What other information is related to the question? Fruit is formed from the ovary of an angiosperm after double fertilization has occurred. Berries have a fleshy pericarp with thin skin. They may be made from the fusion of multiple carpels and therefore have multiple seeds. Drupes have three layers of pericarp, including a fleshy mesocarp over single seed enclosed in a pit of endocarp. Legumes have a pod that splits to release seeds. The entire pericarp is dry at maturity. A samara has a wing formed from a pericarp, which is used to disperse the seed by flying through the air. Choose Answer Given what you now know, what information is most likely to produce the correct answer? With a fleshy pericarp and thin skin, the cucumber is a berry. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Answering this question correctly depended on your ability to use botanical definitions of fruit in a new situation. If you got an incorrect answer, did you remember that a structure formed from an angiosperm Version 1
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ovary and contains seeds, or that berries are a type of fruit with a fleshy pericarp and thin skin? Did you have trouble extending the concept of a berry (which in culinary terms is often used to describe sweet fruit) to a cucumber (which in culinary terms is often described as a vegetable) to determine the correct answer? 40) A
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Clarify Question What is the key concept addressed by the question? Can you identify major events in angiosperm reproduction? What type of thinking is required? You are being asked to take what you already know and use, or apply, it to identify events of double fertilization Gather Content What do you already know about double fertilization? What other information is related to the question? An orange tree is an angiosperm, as indicated by the presence of flowers and fruit. In angiosperms, the male gametophyte is a pollen grain. It has two cells: a tube cell that forms a pollen tube in the stigma after pollination and a generative cell that forms two sperm by mitosis. The female gametophyte is composed of seven cells: an egg, two synergids, three antipodals, and a central cell with two polar nuclei. Double fertilization occurs when one sperm fuses with the egg to form a zygote and a second sperm fuses with the polar nuclei to form endosperm. Choose Answer Given what you now know, what information is most likely to produce the correct answer? Of the answer options given, only one "A generative cell produces sperm by mitosis." is a correct statement regarding orange tree reproduction. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Answering this question correctly depended on your ability to use your Version 1
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knowledge of angiosperm reproduction in a new situation. If you got an incorrect answer, did you remember that fertilization is fusion of sperm and egg (not pollen and egg), or that both gametophytes and gametes are haploid (so sperm is formed by mitosis)? Did you have trouble extending your understanding of double fertilization to determine the correct answer?
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Chapter 31 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) Zygospores are used to resist harsh conditions. ⊚ ⊚
true false
2) Comparisons of DNA sequences have revealed that glomeromycetes are not in the same clade as the zygomycetes. ⊚ ⊚
true false
3) Fungi are currently classified into seven monophyletic groups based on characteristics of the cells undergoing meiosis. ⊚ ⊚
true false
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 4) Alexander Fleming kept finding mold contamination that was killing his bacterial cultures. This observation eventually lead to the development of the antibiotic penicillin. Why would a fungus produce a compound that is selectively toxic to bacteria? A) Fungi eat bacteria. B) Fungi are killed by bacterial toxins. C) Fungi compete with bacteria for resources. D) Killing bacteria is an accident.
5)
What type of symbiotic relationship is exemplified by mycorrhizal fungi?
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A) Mutualism B) Commensalism C) Parasitism D) Atavism
6) Which gene product would be most useful for distinguishing between a microsporidian and a blastocladiomycete? A) Rubisco B) Chitin C) DNA polymerase D) Phospholipidase E) ATP synthase
7) In leaf cutter ant colonies, the ants clip leaves to feed a fungus garden and then the ants feed on the fungus. Is this a mutualistic relationship? A) No, the ants are parasites on both the leaves and fungus. B) Yes, the ants and the trees are in a mutualistic relationship. C) No, the ants are leaf parasites but have no relationship with the fungus. D) Yes, the ants and the fungus are engaged in a mutually beneficial symbiotic relationship.
8)
What type of symbiotic relationship is exemplified by athlete's foot? A) Mutualism B) Commensalism C) Parasitism D) Atavism
9)
Why are neocallimastigomycetes being studied for biofuel production?
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A) They can ferment glucose into alcohol. B) They can release fermentable sugars from cellulose. C) They can generate methane. D) They provide energy to power fermentation. E) They can extract pollutants from biofuel starting materials.
10)
In what way are bacteria and fungi similar? A) Ecologicalfunction B) Cell wallcomponents C) Design of thenucleus D) Ribosomestructure
11) Baker's yeast is a single-celled ascomycete that is used in bread making. Why does yeast make bread dough rise? A) Yeast cells suck in air when trapped in dough. B) Carbon dioxide is produced during fermentation. C) Multiplication of yeast physically expands the dough. D) The fungal cells burst, causing the dough to expand.
12)
Why are fungi used to clean oil spills? A) Fungi use the hydrocarbons in oil instead of CO2 during photosynthesis. B) The chemicals in oil kill off the fungus's competitors. C) Fungi use the organic molecules in the oil as food. D) Fungi store the hydrocarbons in their large central vacuoles.
13)
Why are microsporidia so hard to classify?
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A) When compared to other eukaryotic organisms, microsporidia are extremely small. B) The intracellular parasitic lifestyle greatly reduces the need for functional organelles. C) They lack nuclei. D) They are very rare.
14)
Which molecule would be an indicator of fungal contamination in a drug preparation? A) Cellulose B) Collagen C) Chitin D) Deoxyribose E) Lignin
15)
The fungal group that is most closely related to ancestral fungi are the A) Zygomycota. B) Chytridiomycota. C) Ascomycota. D) Basidomycota.
16)
Specialized symbiotic associations between the roots of plants and fungi are called A) lichens. B) hyphal associations. C) heterokaryotic junctions. D) mycorrhizae. E) a mycelial unit.
17)
A mass of hyphae in an ascomycete is commonly referred to as a(n)
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A) mycelium. B) mycorrhizae. C) conidium. D) sporangium. E) ascus.
18)
The cell walls of fungi are made up of polysaccharides including A) polyglycans. B) phospholipids. C) bilipid layers. D) glycolipids. E) chitin.
19) a
A symbiotic association between a fungus and a green alga or a cyanobacterium is called
A) lichen. B) mycorrhiza. C) protist. D) kelp. E) mushroom.
20) a(n)
The system of fungal filaments that penetrates and grows through the substrate is called
A) exoskeleton. B) hyphal compartment. C) mushroom. D) mycelium. E) sporangium.
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21) Mycorrhizae, specialized symbiotic associations between the roots of plants and fungi, are characteristic of A) all plants. B) about 90% of all plants. C) about 60% of all plants. D) about 40% of all plants. E) about 20% of all plants.
22)
Diploid cells of animals and plants are genetically similar to fungal A) monokaryotic hyphae. B) dikaryotic hyphae (1n+1n). C) homokaryotic hyphae. D) spores. E) triploid cells.
23)
All of the following are reproductive structures found in some fungi, except for A) asci. B) zoospores. C) zygosporangia. D) mycorrhizae. E) basidia.
24) The fungi that cause serious plant disease, such as Dutch elm disease and chestnut blight, belong to the phylum
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A) Ascomycota. B) Zygomycota. C) Imperfect fungi. D) Basidiomycota. E) Actinomycetes.
25)
Asexual reproduction in ascomycetes takes place by means of A) ascogonia. B) ascospores. C) conidia. D) motile gametes. E) zygospores.
26)
After meiosis, the mature ascus of an ascomycete usually contains A) eight diploid nuclei. B) eight haploid nuclei. C) many multinucleate conidia. D) an egg and a sperm. E) a zygote.
27)
The most economically useful unicellular fungi are A) basidiomycetes. B) actinomycetes. C) yeasts. D) mushrooms.
28)
The fruiting structures formed by secondary mycelia of basidiomycetes are known as
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A) mushrooms. B) yeasts. C) lichen. D) ascocarps. E) basidia.
29) by
The only diploid cell of the life cycle of basidiomycetes is produced within the basidium
A) mitosis. B) meiosis. C) karyogamy. D) ascus bursting. E) budding.
30)
The rusts and smuts that seriously affect crop plants are A) ascomycetes. B) zygomycetes. C) chytrids. D) basidiomycetes. E) actinomycetes.
31)
Lichens are adversely affected by A) humidity. B) sunlight. C) pollution. D) sexual reproduction of the fungal partner. E) asexual reproduction of the photosynthetic partner.
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32) Which of the following fungi usually form arbuscular mycorrhizal associations in which the outer cells of the plant roots are penetrated by the fungal hyphae? A) ascomycetes B) glomeromycetes C) deuteromycetes D) basidiomycetes E) chytridiomycetes
33)
Which one statement does NOT describe the arbuscular mycorrhizae? A) They are the most common mycorrhizal type. B) Fungal hyphae penetrate plant root cells. C) They are partners even with early plants like bryophytes. D) The fungal fruiting body incorporates chloroplasts into its tissues. E) The fungal component is a glomeromycete.
34) Ectomycorrhizae, associations in which the fungal hyphae surround but do not penetrate the cell walls of the plant roots, usually involve A) ascomycetes. B) basidiomycetes. C) zygomycetes. D) ascomycetes and basidiomycetes. E) ascomycetes and zygomycetes.
35)
Which of the following statements best describes the structure of fungal hyphae? A) Long chains of cells, each with one nucleus and its own separate cytoplasm. B) Long chains of cells that share cytoplasm and a cell wall. C) Elaborate webs of extracellular matrix around a few scattered cells. D) Elongated spores formed within reproductive structures. E) Long series of connected chromosomes, encased in a single nuclear envelope.
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36) A particular fungus lives on the bark of damaged spruce trees. This fungus has heterokaryotic hyphae, which means A) there are two genetically identical nuclei in each compartment. B) there are two genetically distinct nuclei in each compartment. C) there are two nuclei in each compartment. D) there is only one nucleus in each compartment.
37)
Lichens are mutualisms between A) yeast and another fungi. B) fungi and an alga. C) fungi and a green plant. D) fungi and a mycorrhizae. E) mycorrhizae and yeast.
38)
Which group of fungi is NOT correctly matched with an example? A) Chytridiomycota—unicellular frog parasites B) Neocallimastigomycota—cellulose-degrading gut symbionts of cows C) Zygomycota—bread molds D) Ascomycota—mushrooms E) Basidiomycota—toadstools
39)
One major difference between ectomycorrhizae and arbuscular mycorrhizae is
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A) ectomycorrhizae are parasitic on plant roots while arbuscular mycorrhizae are not. B) ectomycorrhizae do not penetrate plant roots; arbuscular mycorrhizae penetrate plant roots. C) ectomycorrhizae are more common on plant roots than arbuscular mycorrhizae. D) ectomycorrhizae form mutualisms while arbuscular mycorrhizae are parasitic. E) most ectomycorrhizae are zygomycetes while most endomycorrhizae are basidiomycetes.
40)
Ruminant animals have symbiotic fungi that A) digest cellulose and lignin. B) infect milk-producing glands, fermenting the milk. C) produce toxins in muscle tissue. D) produce natural antibiotics.
41) Which one of the following fungal groups has an alternation of multicellular gametophyte and sporophyte generations? A) Zygomycetes B) Ascomycetes C) Blastocladiomycota D) Chytridiomycetes E) Glomeromycetes
42)
In the life cycle of a zygomycete, after the zygospore is formed, the next event will be A) mitosis. B) meiosis. C) plasmogamy. D) karyogamy. E) dikaryon formation.
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43) A nonphotosynthetic plant sharing a mycorrhizal fungus with a photosynthetic plant is best described as a(n) A) mutualist. B) epiparasite. C) parasite. D) host. E) symbiont.
44) Which one of the following terms best applies to the fungus participant in a typical lichen? A) Mutualist B) Ectomycorrhizal fungus C) Arbuscular mycorrhizal fungus D) Epiparasite
45)
How does fungal mitosis differ from animal mitosis? A) Cytokinesis onlyoccurs in fungal mitosis. B) The nuclear envelope often remains intact in fungal mitosis. C) The spindle apparatus is only found in fungal mitosis. D) Fungi only use meiosis, while true mitosis is only seen in animals.
46)
In basidiomycetes the_________blank is diploid. A) basidium B) primarymycelium C) secondarymycelium D) zygote
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47)
Why is it difficult to treat fungal infections in humans? A) Fungal cells are eukaryotic. B) Fungal cells have a chitonous cell wall. C) Fungal cells are dikaryotic. D) Fungal cells cause chytridiomycosis.
48) What type of fungi are obligate symbionts with plant roots and played a key role in the colonization of lands by plant? A) glomeromycetes B) zygomycetes C) chytridiomycetes D) blastocladiomycetes E) microsporidians
49) Sexual reproduction in zygomycetes differs from sexual reproduction in basidiomycetes in one key way. Which of the following is true of zygomycetes, but not true of basidiomycetes? A) Meiosis to produce haploid spores is delayed, resulting in a discrete diploid state. B) Gametangia of opposite mating types undergo plasmogamy. C) Mushrooms are formed of secondary (dikaryotic) mycelium. D) Haploid nuclei fuse in the process of karyogamy to form a diploid nucleus.
50) After one rainy day, suddenly there are mushrooms all over the lawn! What can explain their sudden appearance?
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A) Cytoplasmic flow allows fungi to grow from spore to fruiting body in under 24 hours. B) The fruiting bodies had already developed underground, but the addition of water allowed them to expand in size quickly and burst through the grass. C) The fungal mycelium had been living underground, and the fruiting body formed rapidly aboveground. D) The unicellular fungi had been scattered on the soil surface, but when it rained they aggragated to form a fruiting body.
51) What is accomplished by the trisporol/4-dehydrotrisporic acid system used by zygomycetes? A) It allows recognition of different mating types and initiates gametangia development. B) It facilitates fertilization of the egg by the flagellated sperm. C) The chemicals are secreted to dissolve nutrients in bread and break them down into sugar. D) The chemicals provide long-range signaling that causes aggregation of all the mycelium in the area.
52) In lichen, if the algae or cyanobacterial partner has to do all the photosynthesis, and the fungus benefits from that sugar production, then why is a lichen considered a mutualistic relationship? A) Because mutualism means one party benefits, and the other party is unharmed. B) Because mutualism means one party benefits, and the other party is harmed. C) Because mutualism is just a generic term for any close-knit species relationship. D) Because the fungus provides minerals, water, and protection.
53) Which type of fungus would be the best choice for using as a genetic model organism in the laboratory? A) A glomeromycete B) A microsporidian C) A neocallimastigomycete D) An ascomycete
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54) If a forest floor was polluted by a chemical that was poisonous to fungi, what consequence would you expect for the plant life? A) There would be little consequence, because plants are only distantly related to fungi. B) The plants would have trouble absorbing water and nutrients from the soil. C) All the plants would grow much better, because pathogenic fungi would die. D) The tree bark would overgrow, because nothing could eat the cellulose or lignan.
55) If a sac fungus had a mutation that prevented meiosis, what would you predict to find in the mature asci? A) Four diploid nuclei B) One diploid nucleus C) Four haploid nuclei D) Eight haploid nuclei E) Eight conidia
56)
What would you predict would occur for a lichen whose symbiont algae suddenly died? A) The fungal partner would die. B) The cyanobacterial partner would die. C) The fungal partner may survive, but grow much slower. D) The fungal partner would quickly recruit a new autotroph.
57) The fungusLaetiporus sulphureus is also called chicken-of-the-woods or the sulfur shelf fungus. Its basidiocarps emerge as bright yellow shelves on the sides of infected trees, and it has white, ellipsoid basidiospores. What phylum does this fungus belong to? A) Ascomycota B) Basidiomycota C) Glomeromycota D) Chytridiomycota E) Zygomycota
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58) The fungus Batrachochytrium dendrobatidis was only discovered in 1998, but it has been blamed for the death of millions of amphibians around the globe. It is aquatic, and its flagellated zoospores have the ability to use chemotaxis to swim towards an amphibian, where it burrows into the skin and secretes enzymes to dissolve and absorb the tissue. What phylum does this fungus belong to? A) Ascomycota B) Basidiomycota C) Glomeromycota D) Chytridiomycota E) Zygomycota
59) An elephant at the zoo has a serious fungal infection. The veterinarian needs to choose a topical treatment (on the skin) or an oral treatment (pills that are swallowed). What fact might influence this choice? A) The pills would be best, since any internal fungi would be harmful pathogens anyway. B) The topical fungicide would be best, since killing off any neocallimastigomycetes could harm the elephant's digestion. C) The pills would be best, since killing off any endophytes in the skin could make the elephant susceptible to insect pests. D) The topical fungicide would be best, since killing off any zygomycetes could harm the elephant's digestion. E) The pills would be best, since killing off any glomeromycetes in the gut would just provide added nutrition.
60) The tiny cells of microsporidia lack mitochondria, but their nuclei contain a few mitochondrial genes. What is the most likely explanation suggested by this finding? A) They eat their host cell's mitochondria to recycle the DNA. B) They are finally starting to evolve mitochondria. C) They gained mitochondrial genes by horizontal gene transfer. D) They likely lost mitochondria after becoming intracellular parasites.
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61) A chemist creates a compound that interferes with the polymerization of Nacetylglucosamine. What effect is this likely to have when applied to cultures of fungi? A) The cell walls will be thin and weak. B) The mycelia will attempt to mate and form gametangia. C) Fermentation rates will greatly increase. D) Spores will be heavier and more resilient.
62) When a researcher finds fungal genes in her plant's DNA sample, she realizes the plant has a fungus living inside it. How can she best determine whether the fungus has a mutalistic or parasitic relationship with the plant? A) Dissect the plant and remove the fungus physically, then see how the plant responds. B) Sequence the fungal genes to determine if they encode harmful or beneficial proteins. C) Treat some plants with fungicide to remove the fungus, then compare the health of plants with and without the fungus. D) Classify the fungus—if not a microsporidian, then it is likely a beneficial endosymbiont.
FILL IN THE BLANK. Write the word or phrase that best completes each statement or answers the question. 63) Fungi, together with bacteria, are the principal_________blank in the biosphere.
64) The symbiotic relationship between green algae or cyanobacteria and fungi produces_________blank.
65) Fungi exist mainly in the form of slender filaments, barely visible to the naked eye, which are called_________blank.
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66) Fungal hyphae in which two genetically distinct kinds of nuclei occur together are said to be_________blank.
67) The yeasts, common molds, morels, and truffles are common and economically important. They are members of the group of fungi called_________blank.
68) A type of fungi that has been long useful for baking, brewing, and wine making, and is now very important in genetic research is_________blank.
69)
Mushrooms are fungi belonging to the phylum_________blank.
70) An_________blank is a nonphotosynthetic plant—a third member of a symbiotic relationship involving a fungus and another plant, obtaining nutrients from these two members.
71) Carcinogenic compounds called_________blank are produced by some strains of Aspergillus flavus that can infest peanuts, corn, and cotton seeds.
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Answer Key Test name: Chap 31_13e_Raven 1) TRUE 2) TRUE 3) FALSE 4) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about the necessity of toxin production by fungi. What type of thinking is required? • Evaluate level: o This question is asking you to weigh and judge, or evaluate, the reason that fungi produce antibacterial compounds. Gather Content What do you already know about fungi and bacteria? What other information is related to the question? • Fungi feed by releasing chemicals into their environment and then absorbing the available nutrients. • Heterotrophic bacteria obtain nutrients by absorbing them from the environment. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • It is not logical to conclude that fungi would expend energy and resources to produce an antibiotic compound by accident. • If fungi are killed by bacterial toxins, the production of antibiotic compounds would be a defense that would be too late to be useful. • If fungi consume bacteria it would not be necessary to kill them first. • Since fungi and heterotrophic bacteria may be feeding on the same resources, they are competitors for those resources. The production of antibacterial compounds by fungi would lessen that competition and would give an advantage to the fungi. Version 1
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to weigh and judge, or evaluate, bacteria and fungi. If you got an incorrect answer, did you remember that heterotrophic bacteria and fungi feed on the same materials, or that the elimination of bacteria would make more resources available to the fungi? Did you have trouble weighing the merits of bacteria and fungi to determine the correct answer? 5) A 6) E
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Clarify Question What is the key concept addressed by the question? • This question is asking about the differences between microsporidians and blastocladiomycetes. What type of thinking is required? • Evaluate level: o This question is asking you to compare and contrast microsporidians and blastocladiomycetes, making it an evaluate-level question. Gather Content What do you already know about microsporidians and blastocladiomycetes? What other information is related to the question? • Microsporidians do not possess mitochondria, so they do not carry out aerobic respiration. • Blastocladiomycetes do posses mitochondria. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since a general characteristic of fungi is a cell wall that is made of chitin, this answer can be disregarded. • Rubisco is used in photosynthesis, so this answer can also be disregarded. • Phospholipidases and DNA polymerases are produced by many fungi, so neither is a differentiating factor. • Since ATP synthase is an enzyme that is used in the mitochondria during aerobic respiration, it would not be present in the microsporidians. ATP synthase could be used to differentiate between Version 1
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microsporidians and other fungi. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to weigh and judge, or evaluate, microsporidians and blastocladiomycetes. If you got an incorrect answer, did you remember that microsporidians lack mitochondria, or the that aerobic respiration occurs in the mitochondria? Did you have trouble comparing microsporidians and blastocladiomycetes to determine the correct answer? 7) D
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Clarify Question What is the key concept addressed by the question? • The key concept here is the nature of the relationship between leaf cutter ants and fungi. What type of thinking is required? • Evaluate level: o This question is asking you to weigh and judge, or evaluate, the relationship between leaf cutter ants and fungi. Gather Content What do you already know about leaf cutter ants and fungi? What other information is related to the question? • Leaf cutter ants cultivate fungi within their colony. • Fungi are fed leaves that the ants cut from surrounding trees. • Within the colony, the fungi receive a sheltered place in which they can grow. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Parasites feed on the host without consuming it entirely. Ants are not parasites. • Since the ants feed on the fungus, they do have an ecological relationship with the fungus. • The trees do not obtain any benefits from the ants, so the relationship between the ants and the trees is not mutualism. • The fungi benefit from their association with the ants by the secure habitat that the ant colony provides. The ants benefit by obtaining a food source from the fungi. Since both benefit, this is a mutualistic Version 1
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relationship. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to weigh and judge, or evaluate, leaf cutter ants and fungi. If you got an incorrect answer, did you remember that leaf cutter ants provide a secure location and nutrients for the fungi, or that the ants benefit by using the fungi as food? Did you have trouble relating leaf cutter ants and fungi to determine the correct answer? 8) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about the nature of the relationship between the fungus that causes athlete’s foot and the human that has the infection. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the symbiotic relationship that is exemplified by athlete’s foot. Gather Content What do you already know about athlete’s foot? What other information is related to the question? • Athlete’s foot is caused by Tinea pedis, which is a fungus. • Tinea pedis is a dermatophyte, which means it feeds on skin. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Atavism involves a return to a primitive form, which is not what occurs with athlete’s foot. • Since commensalism involves a relationship in which one species benefits while the other species is unaffected, it can be disregarded as an answer. • Mutualism is a relationship in which both species benefit. This is not what occurs in the case of athlete’s foot. • Since the fungus is feeding on the skin of the host and the host is receiving no benefit, athlete’s foot is an example of parasitism.
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use symbiotic relationships in a new situation. If you got an incorrect answer, did you remember that commensalism benefits one species while the other is unaffected, or that mutualism benefits both species? Did you have trouble extending the concept of symbiotic relationships to determine the correct answer? 9) B 10) A 11) B
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Clarify Question What is the key concept addressed by the question? • The key concept addressed here is the relationship between yeast and rising bread dough. What type of thinking is required? • Evaluate level: o This question is asking you to weigh and judge, or evaluate, why yeast makes bread dough rise. Gather Content What do you already know about yeast? What other information is related to the question? • Baker’s yeast is a one-celled fungus that is widely used commercially, from bread-making to the production of beer and wine. • In the presence of sugar, yeast undergoes anaerobic respiration in the form of alcoholic fermentation. • The products of alcoholic fermentation are carbon dioxide and ethanol. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Yeast ferment anaerobically; they do not suck in air. • Although yeast may multiply under the right environmental conditions, a population increase of these single-celled fungi would not result in a significant increase in the size of bread dough. • Yeast do not burst as they ferment. • Carbon dioxide, which occurs as gas bubbles at room temperature, is produced by fermentation. The presence of carbon dioxide causes bread Version 1
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dough to rise. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to weigh and judge, or evaluate, the role of yeast in rising bread dough. If you got an incorrect answer, did you remember that yeast undergo anaerobic respiration, or that a product of this respiration is carbon dioxide gas? Did you have trouble connecting yeast to rising bread dough to determine the correct answer? 12) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about the use of fungi in resolving an oil spill. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to fungi as agents of remediation for an oil spill. Gather Content What do you already know about fungi? What other information is related to the question? • Fungi absorb and then metabolize materials from their surrounding environment. • Fungi are known for their ability to break down almost any organic compound, even jet fuel. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Fungi are not photosynthetic, nor do they have central vacuoles, so those answers can be disregarded. • Since fungi are well known for their ability to metabolize anything that is carbon-based, and oil is carbon based, it is reasonable to conclude that they may be used to break down oil. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use fungi in a new situation. If you got an incorrect answer, did you remember that fungi absorb and metabolize materials from their environment, or that fungi can break down a wide variety of organic compounds? Did you have trouble extending the abilities of fungi to determine the correct answer? 13) B
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Clarify Question What is the key concept addressed by the question? • This question is asking about the nature of microsporidia as it relates to their classification. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the classification of microsporidia. Gather Content What do you already know about microsporidia? What other information is related to the question? • Microsporidia are unicellular parasites that utilize a variety of creatures as their hosts. • Microsporidia are associated with human disease. • Mitochondria are absent in microsporidians; they utilize anaerobic respiration. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Their unicellular nature and small size are not factors in the difficulty of classifying microsporidia. • As eukaryotes, microsporidia do have nuclei. • Microsporidia are not rare. • The lack of organelles like mitochondria are a factor in the classification of the microsporidia. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use microsporidia in a new situation. If you got an incorrect answer, did you remember that microsporidia lack mitochondria, or that they utilize anaerobic respiration? Did you have trouble extending the characteristics of microsporidia to determine the correct answer? 14) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about how fungi can be differentiated from other living things. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the identification of fungi. Gather Content What do you already know about fungi? What other information is related to the question? • Fungi absorb nutrients from their surroundings. • Fungi possess cell walls that are composed of chitin. • Fungi can be unicellular or multicellular. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • All living things possess deoxyribose, which is a component of DNA. This would not differentiate fungi. • Lignin and cellulose are characteristic of plants, not fungi. • Collagen is characteristic of animals. • Chitin is present in the cell walls of fungi, so this could be used to differentiate them from plants, and most animals. Reflect on Process Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use fungi in a new situation. If you got an incorrect answer, did you remember that fungi have cell walls that are composed of chitin, or that other microbes lack this polymer? Did you have trouble recognizing the characteristics of fungi to determine the correct answer? 15) B 16) D 17) A 18) E 19) A 20) D 21) B 22) B 23) D 24) A 25) C 26) B 27) C 28) A 29) C 30) D 31) C 32) B 33) D 34) B 35) B 36) B Version 1
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37) B 38) D 39) B 40) A 41) C 42) B 43) B 44) A 45) B 46) D 47) A 48) A 49) A 50) C
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Clarify Question What is the key concept addressed by the question? ● This question is asking about the appearance of mushrooms—the fruiting body of a basidiomycete. What type of thinking is required? ● Apply level:● You are being asked to take what you already know and use, or apply, it to explaining the rapid appearance of the mushrooms. Gather Content What do you already know about mushrooms? What other information is related to the question? ● Mushrooms are the fruiting body of a basidiomycete, and is formed of secondary mycelium. ● The majority of a basidiomycete mycelium is below ground. To facilitate spore dispersal, reproductive structures called basidiocarps form—these can be seen as the caps of mushrooms or toadstools on lawns, or on rotting logs. ● Basidiocarp formation begins with the aggregates of dikaryotic hyphae. Under the correct conditions, these can develop very rapidly into the aboveground structures called basidiocarps. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Based on what we know, the best answer is that the fungal mycelium had been living underground, and the fruiting body formed rapidly aboveground. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to apply Version 1
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your knowledge to a new situation. ● Did you remember that a mushroom is just the fruiting body of a basidiomycete? ● Did you recognize that most of the lifecycle of a basidiomycete happens underground in the form of mycelium? 51) A
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Clarify Question What is the key concept addressed by the question? ● This question is asking about the role of the trisporol/4dehydrotrisporic acid system in zygomycetes. What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to this specific question about the chemicals. Gather Content What do you already know about zygomycetes, trisporol and 4dehydrotrisporic acid? What other information is related to the question? ● In zygomycete sexual reproduction, one mating type (the − strain) produces a chemical called trisporol. The other mating strain (the + strain) produces a chemical called 4-dehydrotrisporic acid. ● The − strain expresses an enzyme to convert the 4-dehydrotrisporic acid into trisporic acid but lacks an enzyme to convert its own trisporol into trisporic acid. The + strain has the enzyme to convert trisporol into trisporic acid but not the enzyme to convert its own 4-dehydrotrisporic acid into trisporic acid. ● In this situation where two strains are able to produce trisporic acid from the chemical released by the other strain, the concentration of trisporic acid reaches levels high enough to trigger the formation of structures for sexual reproduction called gametangia. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Based on this information, the best answer is that It allows recognition of different mating types and initiates gametangia development. Reflect on Process Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● Answering this question correctly depended on your ability to apply your knowledge of zygomycete signaling for this question. ● Did you remember that zygomycetes have two mating types that rely on chemical signaling? ● Did you recognize that the point of the two chemicals and two enzymes is to reveal when two different mating types meet? 52) D
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Clarify Question What is the key concept addressed by the question? ● This question is asking about the mutualism of lichens. What type of thinking is required? ● Apply level:● You are being asked to take what you already know and use, or apply, it to this question. Gather Content What do you already know about mutualism and lichens? What other information is related to the question? ● Mutualistic symbiosis benefits both partners. ● Most of the visible body of a lichen consists of its fungus, but between the filaments of that fungus are cyanobacteria, green algae, or sometimes both. ● The durable construction of the fungus allows lichens to grow anywhere it is relatively dry with a stable substrate. Lichens are resilient to drying and can survive extended periods without water. In harsh, exposed areas, lichens are often the first colonists, breaking down rock to produce new soil. ● The fungi protect their partners from strong light and desiccation. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Based on this, the best answer is that lichen is mutualistic because the fungus provides minerals, water, and protection. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● Answering this question correctly depended on your ability to apply your knowledge to this question. Version 1
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● Did you remember that mutualism means both parties benefit? ● Did you recognize that the fungus partner provides essential services to the lichen? 53) D
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Clarify Question What is the key concept addressed by the question? ● This question is asking which type of fungus would be best to use for a genetic model organism in the lab. What type of thinking is required? ● Apply level:● You are being asked to take what you already know and use, or apply, it to this question. Gather Content What do you already know about these types of fungi? What other information is related to the question? ● Would a glomeromycete be a good choice? No, because they have no sexual reproduction, and can only be cultured on plant roots. ● Would a microsporidian be a good choice? No, because they are obligate intracellular parasites. ● Would a neocallimastigomycete be a good choice? No, because they are symbionts that live in the guts of cows, etc. ● Would an ascomycete be a good choice? Yes! They have both sexual and asexual reproduction and are easily cultured in the lab. There are safe species to work with. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● So a species of ascomycete would be the best choice. In fact, several yeast species have been used as genetic model organisms for decades. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● Answering this question correctly depended on your ability to use your knowledge in a new situation. Version 1
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● Did you remember the characteristics of the different fungal phyla? ● Did you recognize that a genetic model organism has to be easy to grow in the lab, and that sexual reproduction is beneficial? 54) B
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Clarify Question What is the key concept addressed by the question? ● This question is asking about consequences of loss of fungi in a forest. What type of thinking is required? ● Evaluate level:● You are being asked to weigh the options and judge, or evaluate, which best sums up the consequences. Gather Content What do you already know about fungi? What other information is related to the question? ● Fungi are decomposers that recycle dead organic matter. ● They have the rare ability to digest cellulose and lignan. ● There are some pathogenic fungi that cause diseases in plants. ● Fungi are more closely related to animals than plants. ● Some fungi are endophytic, living within a plant partner, often providing some protection against insects. ● Most plants have mycorhizzal fungi in their roots, that help them absorb water and nutrients. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Based on weighing all this information, the best answer is that the plants would have trouble absorbing water and nutrients from the soil, because killing their mycorrhizal partners would destroy this important role played by the fungi. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Evaluate level:● Answering this question correctly depended on your ability to use your knowledge in a new situation. Version 1
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● Did you remember that most plants benefit from mycorrhizae? ● Did you recognize that this would probably be the most important effect from loss of fungi? 55) B
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Clarify Question What is the key concept addressed by the question? ● This question is asking about the ascomycete lifecycle. What type of thinking is required? ● Apply level:● You are being asked to take what you already know and use, or apply, it to this question. Gather Content What do you already know about the ascomycete lifecycle? What other information is related to the question? ● Certain hyphae in the ascocarp develop into structures called asci (singular, ascus) inside the ascocarp. ● Karyogamy results in the production of a diploid nucleus at the tip of forming asci. ● In mature asci, the diploid nucleus undergoes meiosis to produce four haploid cells, each of which then undergoes a single mitosis to produce eight haploid ascospores. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● If meiosis did not proceed, then the product of the ascus would remain the one diploid nucleus seen after karyogamy. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● Answering this question correctly depended on your ability to use your knowledge in a new situation. ● Did you remember the details of the ascomycete lifecycle? ● Did you recognize that without meiosis, the single diploid nucleus would likely remain? Version 1
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56) C
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Clarify Question What is the key concept addressed by the question? ● This question is asking about a lichen that lost its alga. What type of thinking is required? ● Apply level:● You are being asked to take what you already know and use, or apply, it to this question. Gather Content What do you already know about lichens? What other information is related to the question? ● Lichens are a symbiosis between a fungus and a photosynthetic partner. ● The fungi in lichens are unable to grow normally without their photosynthetic partners, and the fungi protect their partners from strong light and desiccation. ● When fungal components of lichens are isolated from their photosynthetic partners, they survive, but grow very slowly. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Based on this information, the best answer is that the fungal partner might survive, but grow slower. It would be lacking the free nutrients from photosynthesis, but it would still be able to absorb nutrients from the environment. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● Answering this question correctly depended on your ability to use your knowledge in a new situation. ● Did you remember that lichens typically consist of one fungus and one Version 1
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photosynthesizer, either an alga or cyanobacterium? ● Did you recognize that the fungus could still absorb food from other sources? 57) B
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Clarify Question What is the key concept addressed by the question? ● This question is asking you to identify the phylum of a species of fungus. What type of thinking is required? ● Apply level:● You are being asked to take what you already know and use, or apply, it to this question. Gather Content What do you already know about the phyla of fungi? What other information is related to the question? ● Is it likely to be a member of the Ascomycota? No. The sac fungi include morels, cup fungi, and yeasts, and they have ascocarps and ascospores. ● Is it likely to be a member of the Glomeromycota? No. The glomerocetes live as arbuscular mycorrhizae, reproduce asexually, and they don't have basidiocarps or basidiospores. ● Is it likely to be a member of the Chytridiomycota? No. The chytrid fungi are aquatic and unicellular, and they don't have basidiocarps or basidiospores. ● Is it likely to be a member of the Zygomycota? No. The zygomycetes include the bread molds, are mostly asexual, and they don't have basidiocarps or basidiospores. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Based on this information, the fungus is a basidiomycete, from the phylum Basidiomycota. The basidiomycetes have basidiocarps and basidiospores. They also include many species with large fruiting bodies. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● Answering this question correctly depended on your ability to use your knowledge in a new situation. ● Did you remember that basidiocarps and basidiospores are features of the Basidiomycota? ● Did you recognize that a fungus with a large fruiting body growing on a tree is likely to be a basidiomycete? 58) D
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Clarify Question What is the key concept addressed by the question? ● This question is asking you to identify the phylum of a species of fungus. What type of thinking is required? ● Apply level:● You are being asked to take what you already know and use, or apply, it to this question. Gather Content What do you already know about the phyla of fungi? What other information is related to the question? ● Is it likely to be a member of the Ascomycota? No. The sac fungi include morels, cup fungi, and yeasts, are not generally aquatic, and they don't have flagella or zoospores. ● Is it likely to be a member of the Glomeromycota? No. The glomerocetes live as arbuscular mycorrhizae, are not generally aquatic, and they don't have flagella or zoospores. ● Is it likely to be a member of the Basidiomycota? No. The basidiomycetes include many kinds of mushrooms, are not generally aquatic, and they don't have flagella or zoospores. ● Is it likely to be a member of the Zygomycota? No. The zygomycetes include the bread molds, are not generally aquatic, and they don't have flagella or zoospores. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Based on this information, the fungus is a chytridiomycete, from the phylum Chytridiomycota. The chytrids are aquatic and form flagellated Version 1
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zoospores. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● Answering this question correctly depended on your ability to use your knowledge in a new situation. ● Did you remember that flagellated zoospores are features of the Chytridiomycota? ● Did you recognize that an aquatic fungus that attacks amphibians is likely to be a chytrid? 59) B
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Clarify Question What is the key concept addressed by the question? ● This question is asking about possible consequences of the use of fungicide on an elephant. What type of thinking is required? ● Apply level:● You are being asked to take what you already know and use, or apply, it to this question. Gather Content What do you already know about fungi? What other information is related to the question? ● Are there likely to be endophytes in the elephant's skin that protect from insect pests? No, endophytes live inside plants, not animals. ● Are there likely to be zygomycetes inside the elephant? Not likely, those are species like bread molds and the mold that produces tempeh. ● Are there likely to be glomeromycetes in the gut? Not much. Those are the fungi that form arbuscular mycorrhizae with plant roots. This isn't a major consideration. ● Are any internal fungi harmful pathogens anyway? Not necessarily. Sometimes fungi have mutualistic relationships with animals. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Based on this information, the best answer is that the topical fungicide would be best choice, since killing off any neocallimastigomycetes could harm the elephant's digestion. Neocallimastigomycetes are anaerobic fungi in the gut of grazing animals that help them digest cellulose in the plant material they eat to gain more nutrition from it. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? ● Apply level:● Answering this question correctly depended on your ability to use your knowledge in a new situation. ● Did you remember that grazing animals have neocallimastigomycetes in their guts for digestion? ● Did you recognize that some fungi are beneficial, even though some are pathogens? 60) D
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Clarify Question What is the key concept addressed by the question? ● This question is asking you to interpret the finding that microsporidia lack mitochondria but have a few mitochondrial genes. What type of thinking is required? ● Apply level:● You are being asked to take what you already know and use, or apply, it to this question. Gather Content What do you already know about microsporidia? What other information is related to the question? ● Microsporidia are small (1 to 4 μm diameter), obligate, intracellular parasites of crustaceans, insects, and fish, and in some cases, even humans. ● Although microsporidia lack mitochondria, their genomes, which are smaller than all eukaryotes’ genomes and even some bacteria, contain genes related to mitochondrial function. In some cases the absence of ancient glycolytic pathways makes the parasite completely dependent on the host for ATP and glycolytic intermediates. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Based on this information, the best answer is that they likely lost mitochondria after becoming intracellular parasites. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● Answering this question correctly depended on your ability to use your knowledge in a new situation. ● Did you remember that mitochondrial genes often get moved to the Version 1
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nucleus? ● Did you recognize that those few genes reveal that the microsporidia previously had mitochondria? 61) A
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Clarify Question What is the key concept addressed by the question? ● This question is asking about the result of blocking polymerization of N-acetylglucosamine. What type of thinking is required? ● Apply level:● You are being asked to take what you already know and use, or apply, it to this question. Gather Content What do you already know about fungi? What other information is related to the question? ● Fungi have cell walls composed primarily of the polysaccharide chitin. Chitin is a polymer made from a modified, nitrogen-containing form of glucose called N-acetylglucosamine. The polymers of Nacetylglucosamine are then cross-linked with proteins. ● Chitin is also found in the exoskeletons of mollusks, insects, and crustaceans Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Based on this information, the best answer is that the cell walls will be thin and weak. Since polymerized N-acetylglucosamine is the basis of chitin, which forms the cell walls of fungi, interfering with this would greatly disrupt the cell walls. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● Answering this question correctly depended on your ability to use your knowledge in a new situation. ● Did you remember that fungal cell walls are made of chitin? And that Version 1
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chitin is polymerized N-acetylglucosamine? ● Did you recognize that interfering with chitin would make the cell walls weak and flimsy? 62) C
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Clarify Question What is the key concept addressed by the question? ● This question is asking how to determine whether a plant fungus is a parasite or a mutualist. What type of thinking is required? ● Apply level:● You are being asked to take what you already know and use, or apply, it to this question. Gather Content What do you already know about endophytes? What other information is related to the question? ● Some species of fungi live inside plants, residing in intercellular and apoplastic spaces, obtaining nutrients from the plant. In some cases the fungi produce compounds such as alkaloids that protect the plant against herbivory; in other cases, fungal products might increase nutrient absorption by the plant. ● The relationship between these endophytic fungi and a plant can be parasitic, commensal, or mutualistic. ● One way to assess whether an endophyte is enhancing the health of its host plant is to grow plots of plants with and without an endophyte and to measure the impact the endophyte has on plant health or susceptibility to herbivory. An experiment with perennial ryegrass, Lolium perenne, demonstrated that it is more resistant to aphid feeding when an endophytic fungus, Neotyphodium, is present. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Based on this information, the best answer is to treat some plants with fungicide to remove the fungus, then compare the health of plants with and without the fungus. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● Answering this question correctly depended on your ability to use your knowledge in a new situation. ● Did you remember that some fungi are endophytes with a beneficial relationship, but others are parasites? ● Did you recognize that the best way to determine the relationship is to compare plant health with and without the presence of the fungus? 63) Decomposers 64) Lichens 65) Hyphae 66) Heterokaryotic 67) Ascomycetes 68) Yeasts 69) Basidiomycota 70) Epiparasite 71) Aflatoxins
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Chapter 32 13e CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 1) As a teaching assistant, you must gather examples of deuterostomes from a large, unorganized selection of animals. Which specimens should you select? (Check all that apply.) A) Jellyfish B) Sea urchins C) Sea stars D) Acoel flatworms E) Anemones
2) A member of your study group is unfamiliar with cnidarians and is struggling with understanding the difference between cnidarian polyps and medusae. How can you help your classmate to grasp the difference? Check all of the correct statements. A) Only polyps are colonial. B) A species contains either polyps or medusae, but not both. C) Both polyps and medusae are diploid. D) Polyps and medusae both have mouths surrounded by tentacles.
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 3) Damage to its flagellum would prevent a choanocyte from A) circulating waterthrough the sponge. B) stinging and capturing prey. C) secreting sponginto form the sponge body. D) producing thesupportive spicules.
4) Touching a jellyfish can be a very painful experience whereas touching a comb jelly is not painful. Why is there a difference?
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A) Nematocysts inctenophores lack venom. B) Ctenophores havevery reduced nematocysts that cannot penetrate human skin. C) Ctenphores do notpossess nematocysts. D) Ctenophores onlyuse nematocycts for feeding, not for defense.
5)
How could a biologist distinguish an acoel flatworm from a free living platyhelminth? A) The acoel worm would be solid throughout, since it lacks a gut. B) The acoel worm would have a nervous system. C) The platyhelminth would have a more primitive gut and nervous system. D) Only the acoel is triploblastic.
6) A mixture of DNA fragments is amplified from a sample of ocean water. Which gene(s) could be definitively categorized as originating from a species of animal? A) Genes for ATP synthase B) Gene for Spongin C) Cell cycle regulatory genes D) Genes for biosynthesis of chitin E) Gene for RuBisCO
7) Linnaeus lumped all of the worm-like animals into the category Vermes (Vermis is Latin for worm). Is this a valid classification scheme? A) No, because someworms are protists. B) Yes, because allworms are members of the same phylum. C) Yes, because allworm-like animals are more closely related to each other than they are to otheranimals. D) No, because the worm-like body plan has appeared many times through evolutionary history and is not a useful trait for classification.
8)
Of the following features, which is the most widely shared in the animal kingdom?
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A) protostomedevelopment B) radial cleavage C) molting of a cuticle or exoskeleton D) a body plan with symmetry E) a triploblastic embryo
9) A scientist is studying some developing eggs from an ocean sample. The early embryos have divided only a few times, and all cells look identical. When the scientist carefully removes half the cells from an embryo, both clumps of cells are able to complete development, forming twins. The eggs can be identified as A) deuterostomes. B) protostomes. C) crustaceans. D) cnidarians. E) echinoderms.
10) As a teaching assistant, you are grading lab reports and notice that in a sketch of a crosssection of a roundworm, a student labeled the space between the inner lining of the body wall and the wall of the digestive cavity as the coelom. How should you grade this label? A) The label is correct. The endodermal wall of the digestive cavity and the mesodermal lining of the body will make up the boundaries of a coelom. B) The label is incorrect. The space is immediately enclosed by an ectoderm, so it is a body cavity and not a coelom. C) The label is correct. The coelom is the space that occurs outside of the digestive cavity. D) The label is incorrect. The space is not fully enclosed by mesoderm, so it is a body cavity, but it is not a coelom.
11) Given the distribution of the animal phyla across the Earth's various ecosystems, what would be the most likely habitat for the origin of animals?
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A) Rain forests B) Freshwaterhabitats C) Deserts D) Oceans E) Temperate grassland
12) Of the following combination of statements about protostomes and deuterostomes, which choice is correct? A) Protostomes are animals in which the mouth develops from the blastopore, and the anus or anal pore develops from the second opening. Deuterostomes are animals in which the anus develops from the blastopore and the mouth develops secondarily later in their development. B) Protostomes are animals in which the anus develops from the blastopore, and the mouth develops from the second opening. Deuterostomes are animals in which the anus develops from the blastopore and the mouth develops secondarily later in their development. C) Protostomes are animals in which the mouth develops from the blastopore, and the anus or anal pore develops from the second opening. Deuterostomes are animals in which the mouth develops from the blastopore and the anus develops secondarily later in their development. D) Protostomes areanimals in which the mouth or anus develops from the blastopore, depending onthe species. Deuterostomes are animals in which the mouth and anus developsfrom the blastopore, depending on the species.
13)
Protostomes develop through A) spiral cleavage. B) radial cleavage. C) axial cleavage. D) polar cleavage. E) proto cleavage.
14)
In animals that display indeterminate development
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A) embryonic cells have a predetermined fate. B) bilateral symmetry cannot develop. C) early embryonic cells, if separated from the embryo, can develop into complete organisms. D) embryonic cells show spiral cleavage. E) the blastopore develops into the mouth.
15) A biologist discovered a new animal. Upon studying its embryonic development, she observed radial cleavage with the blastopore developing into an anus. This animal was categorized as a A) parazoan. B) radiata. C) deuterostome. D) protostome. E) pseudocoelomate.
16)
Solid worms that lack a body cavity are known as A) acoelomates. B) pseudocoelomates. C) triploblastic. D) coelomates. E) diploblastic.
17)
Which of the following terms is mismatched with its meaning or characteristics? A) Diploblastic—ectoderm and mesoderm B) Triploblastic—ectoderm, mesoderm, and endoderm C) Parazoa—lacks symmetry; no tissues D) Eumetazoa—definite symmetry; tissues organized E) Chordate—animal with notochord
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18)
What are the three animal phyla that dominate animal life on land? A) Cnidaria, Mollusca, Platyhelminthes B) Porifera, Arthropoda, Nematoda C) Nematoda, Chordata, Cnidaria D) Nematoda, Arthropoda, Chordata E) Platyhelminthes, Nematoda, Arthropoda
19) Although it is recognized that segmentation is more widespread than previously thought, traditionally segmentation was said to be found in A) Annelida, Mollusca, and Arthropoda. B) Echinodermata, Platyhelminthes, and Cnidaria. C) Mollusca, Chordata, and Annelida. D) Arthropoda, Chordata, and Porifera. E) Arthropoda, Annelida, and Chordata.
20) Molecular data confirm that cnidarians branched off from the rest of animals before_________blank evolved. A) echinoderms B) Porifera C) mollusks D) bilaterial symmetry E) arthropods
21)
Parazoa
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A) are pseudocoelomates. B) exhibit bilateral symmetry. C) include Cnidaria and Ctenophora. D) exhibit primitive segmentation. E) have no true tissues.
22)
Which one of the following terms applies to the phylum Arthropoda? A) radial symmetry B) diploblastic C) coelomate D) Parazoa E) deuterostome
23)
Which one of the following terms applies to the phylum Mollusca? A) protostome B) pseudocoelomate C) Parazoa D) diploblastic E) asymmetry
24)
Which one of the following terms applies to the phylum Platyhelminthes? A) radialcleavage B) deuterostome C) diploblastic D) acoelomate E) radial symmetry
25)
Which one of the following terms applies to the phylum Nematoda?
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A) Parazoa B) diploblastic C) deuterostome D) pseudocoelomate
26)
Which one of the following terms applies to the phylum Cnidaria? A) radial symmetry B) pseudocoelomate C) Parazoa D) triploblastic E) protostome
27) Select the phylum that includes deuterostome animals that are exclusively marine and have radial symmetry as adults. A) Porifera B) Rotifera C) Echinodermata D) Chordata E) Cnidaria
28)
Which one of the following terms applies to the phylum Bryozoa? A) radial symmetry B) lophophore C) Parazoa D) deuterostome E) radial cleavage
29)
Which one of the following applies to the phylum Ctenophora?
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A) often bioluminescent marine animals B) protostome C) coelomate D) deuterostome E) Parazoa
30) Select the following phylum that includes coelomate, bilaterian animals that have a structure called a notochord. A) Echinodermata B) Annelida C) Arthropoda D) Mollusca E) Chordata
31) Select the following phylum that includes animals that are unsegmented, acoelomate, and have a digestive cavity with a single opening. A) Annelida B) Platyhelminthes C) Nematoda D) Cnidaria E) Rotifera
32)
Which one of the following features is unique to animals? A) cells organized into tissues B) movement associated with muscle tissue and nervous tissue C) heterotrophism D) cells without walls E) embryonic development
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33)
Which of the following describes what is currently known about Ctenophore symmetry? A) Ctenophores are diploblasts with bilateral symmetry. B) Ctenophores are possibly triploblasts because of muscle cells derived from meoderm. C) Ctenophores are bilaterians. D) Ctenophores are lacking symmetry.
34) Predict what would occur if the nematocysts of a cnidarian were no longer able to function. A) Eggs would be released into the environment. B) Food capture would cease. C) Water could not flow through the gastrovascular cavity. D) They would not be able to move.
FILL IN THE BLANK. Write the word or phrase that best completes each statement or answers the question. 35) In all deuterostomes, pairs of cells from each division are placed directly above and below each other. This pattern is called_________blank.
36) The embryonic layer found only in bilaterally symmetrical eumetazoans is the_________blank.
37) Animals with a body cavity located between the mesoderm and endoderm are_________blank.
38) In a_________blank circulatory system, circulation of blood is more controlled—the blood is moved faster and more efficiently than in other types of circulatory systems.
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39) Two outwardly dissimilar groups, the_________blank and the chordates, together with a few other small phyla, constitute the deuterostomes.
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Answer Key Test name: Chap 32_13e_Raven 1) [B, C]
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Clarify Question ● What is the key concept addressed by the question? ● The classification of deuterostomes. ● What type of thinking is required?● You are being asked to take what you already know and use, or apply, it to the recognition of deuterostomes. Gather Content ● What do you already know about deuterostomes? What other information is related to the question? ● Deuterostomes may be vertebrates or invertebrates. ● Jellyfish and anemones belong to the same phylum. ● Sea stars and sea urchins belong to the same phylum. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer? ● Did you recognize that sea stars and sea urchins are members of the phylum Echinodermata? ● Did you recall that echinoderms are deuterostomes? Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use your knowledge of deuterostome classification in a new situation… If you got an incorrect answer, did you remember that deuterostomes include echinoderms as well as vertebrates? 2) [A, C, D]
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Clarify Question ● What is the key concept addressed by the question?● Polyp and medusa body forms ● What type of thinking is required?● You are being asked to take what you already know and use, or apply, it to the assessment of cnidarian polyp and medusa body forms. Gather Content ● What do you already know about cnidarian body forms? What other information is related to the question?● Polyps are cylindrical body forms of cnidarians. ● Medusae are jellyfish. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● Polyps may be colonial, but medusae are not colonial. ● The polyp and medusa stages can alternate within the life history of a species. ● Medusae are jellyfish. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Answering this question correctly depended on your ability to use cnidarian body forms in a new situation… If you got an incorrect answer, did you remember that polyps may be colonial, but medusae are not colonial, or that the polyp and medusa stages can alternate within the life history of a species? Did you have trouble assessing the ploidy of Version 1
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these body forms to determine the correct answer? 3) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses sponge morphology. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about sponge morphology?● A small, anatomically simple sponge has a vaselike shape. The walls of the “vase” have three functional layers. ● Facing the internal cavity are flagellated cells called choanocytes, or collar cells. Once water has passed through a flagellated chamber, it travels through channels that converge at a large opening called an osculum through which water is expelled from the sponge. ● The body of a sponge is bounded by an outer epithelium consisting of flattened cells somewhat like those that make up the outer layers of animals in other phyla. ● Pores on the sponge allow water to enter the channels that course through its body, leading to and from the flagellated chambers. The name of the phylum, Porifera, refers to these pores, or ostia. ● Some epithelial cells are specialized to surround the ostia; they can contract when touched or exposed to appropriate stimuli, causing the ostia to close, thereby protecting the delicate inner cells from the entry of potentially harmful substances such as sand and noxious chemicals. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The choanocyte flagella are necessary to circulate water through the sponge.
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the choanocytes move water through the sponge body using their flagella? 4) C 5) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses acoel flatworms. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about acoel flatworms?● Acoel flatworms are the simplest bilaterians. They are called “acoel” because they lack a coelom. ● They are the sister group to all the other Bilateria – the protostomes and the deuterostomes. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Acoel flatworms lack a gut. They also have a primitive nervous system. ● Platyhelminthes, in contrast, have a proper gut and a more advanced nervous system. They are superficially similar to acoel flatworms, but different on the inside. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that acoel flatworms lack a gut, and have a more primitive nervous system than the playhelminthes? 6) B Version 1
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Clarify Question ● What is the key concept addressed by the question?● This question addresses animal genes. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about animal genes?● Some of the genes listed are expressed in animals, some are not. Only one is expressed in animals but not other organisms. ● ATP synthase – This enzyme synthesizes ATP, which is used by many organisms. Not unique to animals. ● RuBisCO – This enzyme plays a role in carbon fixation by plants. Not in animals. ● Cell cycle regulatory genes – All multicellular organisms have to regulate their cell cycle. Not unique to animals. ● Genes for biosynthesis of chitin – Chitin is a polysaccharide found in arthropods and mollusks, but also in fungi and algae. Chitin is not unique to animals. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Spongin is the tough protein in mesohyl that provides strength to the body of sponges. Since a sponge is an animal, this gene originated from an animal. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The Version 1
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question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that spongin is a protein in sponges, which are a type of animal? 7) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses animal classification. ● What type of thinking is required?● This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. Gather Content ● What do you already know about animal classification?● Animals are classified according to their evolutionary relationships. ● In cladistics, scientists attempt to group animals into monophyletic clades – that is, a group in which all members are more closely related to each other than any members are to another type of organism. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Consider some different types of “worms”: ● Acoel flatworms – In the phylum Acoela, the sister group to all other Bilateria. ● Platyhelminthes – Flatworms like planaria. ● Annelida – Segmented worms, including earthworms and leeches. ● Nematoda – Tiny roundworms, such as C. elegans. ● Nemertea – A group of marine worms. ● Chaetognatha –Arrow worms, which have an uncertain phylogenetic placement. ● It is clear that the worm body plan has been a common solution hit upon during evolution of the animals. It has appeared many times through evolutionary history and is not a useful trait for classification.
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. ● Did you recognize that “worm” body plans are common in distantlyrelated animal phyla, and thus provide no useful classification information? 8) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses features of animals. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content ● What do you already know about features of animals?● The animal features listed were generally maintained in large clades after they evolved. ● These features describe aspects of development, but they also characterize large clades that share each feature. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Consider each feature in turn: ● Molting of a cuticle or exoskeleton – This is a characteristic of the Ecdysozoa, a subset of the protostomes. ● Protostome development – Found, naturally, in all the protostomes. ● Radial cleavage – This is a characteristic of the deuterostomes. ● A triploblastic embryo – These are found in all the Bilateria. ● A body plan with symmetry – This is a feature not just of the bilateral animals (Bilateria), but also of animals with radial symmetry (Cnidaria). Only the Porifera have an asymmetrical body plan. Thus, “symmetry” is the most widespread feature. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that symmetry – whether radial or bilateral – is the oldest and most widely shared animal feature? Only the sponges lack symmetry. 9) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses determinate and indeterminate development. ● What type of thinking is required?● This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. Gather Content ● What do you already know about determinate and indeterminate development?● Many protostomes exhibit determinate development, in which the type of tissue each embryonic cell will form in the adult is determined early, in many lineages even before cleavage begins, when the molecules that act as developmental signals are localized in different regions of the egg. Consequently, each embryonic cell is destined to occur only in particular parts of the adult body, so if the cells are separated, development cannot proceed. ● Deuterostomes, conversely, display indeterminate development. The first few cell divisions of the zygote produce identical daughter cells. If the cells are separated, any one can develop into a complete organism (this is how identical twins are formed). Thus, each cell remains totipotent and its fate is not determined for several cleavages. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Since the embryos could be split in half and still form normally, this indicates they have indeterminate development. ● Indeterminate development is a feature of deuterostomes. However, based on just this information we can not identify what type of deuterostome. Version 1
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. ● Did you recognize that the split embryos showed indeterminate development, a characteristic of deuterostomes? 10) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the nature of a coelom. ● What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to the comparison of a body cavity and true coelom. Gather Content ● What do you already know about body cavities? What other information is related to the question?● A space inside the body wall does not necessarily indicate a coelom is present. ● A true coelom is lined with and surrounded by tissue derived from the mesoderm. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● Because the mesodermal lining is not present on both sides of the cavity, this is not a true coelom. ● Roundworms have a pseudocoel, which is a body cavity, but not a true coelom. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Answering this question correctly depended on your ability to use your knowledge of coeloms in a new situation… If you got an incorrect answer, did you recognize that the lack of mesodermal lining on the wall of the digestive cavity was an indication that this is not a true coelom?
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11) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses animal phyla. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about animal phyla?● Consider the major animal phyla from Table 32.1: ● Arthropoda – Marine, terrestrial, a few freshwater ● Mollusca – Mostly marine, a few terrestrial and freshwater ● Chordata – Marine, terrestrial, and freshwater ● Platyhelminthes – Marine and freshwater, a few terrestrial ● Nematoda – Marine, freshwater and terrestrial ● Annelida – Marine, freshwater and terrestrial ● Porifera – Marine ● Echinodermata – Marine ● Cnidaria – Marine, a few terrestrial ● Bryozoa – Marine Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The commonality between the animal phyla is marine habitat. Some phyla are entirely or almost entirely restricted to a marine habitat. ● This makes sense since the Cambrian explosion of animal phyla occurred in the oceans. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that many of the animal phyla live mostly or entirely in the ocean, reflecting their evolutionary origin? 12) A 13) A 14) C 15) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses animal development. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about animal development?● In spiralian protostomes, embryonic cells cleave in a spiral pattern and exhibit determinate development; the blastopore becomes the animal’s mouth, and the coelom originates from a split among endodermal cells. ● In deuterostomes, embryonic cells cleave radially and exhibit indeterminate development; the blastopore becomes the animal’s anus, and the coelom originates from an invagination of the archenteron. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The group of animals known for radial cleavage, and development of the blastopore into the anus is the deuterostomes. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the deuterostomes are the group of animals that are characterized by radial cleavage, and development of the blastopore into the anus? Version 1
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16) A 17) A 18) D 19) E 20) D 21) E 22) C 23) A 24) D 25) D 26) A 27) C 28) B 29) A 30) E 31) B 32) B 33) B 34) B
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Clarify Question ● What is the key concept addressed by the question?● The role of nematocysts in the cnidarian body ● What type of thinking is required?● You are being asked to take what you already know and use, or apply, it to explain the function of nematocysts. Gather Content ● What do you already know about nematocysts? What other information is related to the question?● Nematocysts occur in cnidarian cells called cnidocytes. ● Nematocysts contain filaments that can be rapidly expelled. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● The filaments of nematocysts can be used to secure food items in various ways. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Answering this question correctly depended on your ability to use nematocysts in a new situation. If you got an incorrect answer, did you remember that nematocysts are stinging organelles? Did you have trouble extending the form and function of nematocysts to determine the correct answer? 35) radial cleavage 36) mesoderm
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37) pseudocoelomates 38) closed 39) echinoderms
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Chapter 33 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) The side-to-side thrashing of a nematode is accomplished by the contraction of its circular muscles. ⊚ ⊚
true false
CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 2) A spider and an insect are both arthropods, but they have some different characteristics. Choose the descriptions that are true for BOTH a spider and an insect. Check all that apply. A) They have a head, a thorax, and an abdomen. B) They have an open circulatory system. C) Some species are carnivorous and some are herbivorous. D) They have a chitinous exoskeleton. E) They have spinnerets. F) They molt. G) They are members of Ecdysozoa. H) They have sensory antennae. I) They have metamorphosis.
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 3) Dibenzoylhydrazines are a category of molecules that have been used as insecticides. They work by blocking ecdysteroid receptors. How does this kill an insect? A) The insect can nolonger excrete nitrogenous wastes. B) The insect cannotmolt. C) The insect can nolonger coordinate its movements. D) The chitinousexoskeleton is dissolved.
4) At a celebratory dinner for a recent publication, a marine biologist ordered the lobster claw appetizer. What part did she order? Version 1
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A) Nauplius B) Telson C) Uropods D) Cheliped
5) A collection of arthropods is sitting in the lab prep room, and as a teaching assistant, you must select a hexapod from this diverse group of specimens to show your class. Which characteristic will quickly make you certain that what you have selected is a hexapod? A) Jointedappendages B) Mandibles C) Chitinousexoskeletons D) Wings E) Antennae
6)
In what way are a human and a crab similar? A) Vertebrates andarthropods are deuterostomes. B) Both have musclesthat pull against rigid skeletons. C) Both have closedcirculatory systems. D) Both have a continuous growth pattern.
7) Barnacles are sessile filter feeders but unlike bivalves, they have internal fertilization. How do they solve this problem? A) The filter spermfrom the water column. B) They getfertilized during free living larval stages. C) They are onlycapable of asexual reproduction. D) They are hermaphrodites with, especially long penises.
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8) An entomologist observed a locust sitting on a branch pumping its abdomen like an accordion. What is the insect most likely doing? A) Speeding the flowof blood through its veins and arteries B) Assisting gasexchange in the tracheal system C) Clearing its spinnerets D) Stretching outits pedipalps
9) Scorpions have a prosoma, pedipalps that are modified into claws, and chelicerae. Which taxonomic group are they a member of? A) Chelicerata B) Hexapoda C) Crustacea D) Myriapoda
10) The lophophore of a brachiopod serves the same function as the_________blank in a bivalve. A) Mantle B) Foot C) Shell D) Gills
11) How would an earthworm stretch its body to reach a patch of dirt after crossing a hot sidewalk? A) Contraction ofthe circular muscles B) Contraction ofthe longitudinal muscles C) Relaxing the chaetae (setae) D) Pulling on the chaetae (setae)
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12) Pinworm is a nematode parasite that lives in the human rectum, and causes itching in the anal area. What best explains the itching symptom? A) Any kind of parasite will naturally irritate the skin. B) The itching induces the person to scratch, helping to spread the parasite to another person. C) The itching is a side-effect when the immune system has successfully attacked the nematode. D) The itching is because of the mismatch between humans and the parasite’s natural host.
13) How could a paleontologist distinguish between a bryozoan fossil and a brachiopod fossil? A) Bryozoans are large and solitary. B) Zoecia are always found in aggregates. C) You can only distinguish the two by examining the lophophore. D) Bryozoans often look like bivalves.
14) What would result if a leech had a mutation causing it to secrete low levels of anticoagulants? A) The pain of theleech bite would cause the leech to be detected. B) The leech wouldhave a hard time locating appropriate hosts. C) The blood wouldstop flowing after a short time. D) The leech wouldhave a hard time remaining attached to its host.
15) Inside its beak, an octopus has a rasping tongue that is used to tear apart food. Which gastropod structure is this analogous to? A) Mantle B) Shell C) Radula D) Nephridium
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16) What is a simple way for determining if an annelid is a member of Errantia (a polychaete) or Sedentaria (a clitellate)? A) The number ofsegments B) Possession of a closed circulatory system C) The amount of chaetae (setae) D) The layout of thedigestive system
17)
Interoctopus communication is facilitated by A) a radula. B) mantleconnections. C) chromatophores. D) chemicalpheromones.
18) Humans have direct development, a closed circulatory system, well-developed eyes, and large brains. Which mollusk also shares these features? A) Chiton B) Slug C) Octopus D) Nudibranch
19) A snail in your garden and an oyster are quite different in appearance. What would be evidence to justify grouping them together? A) Both use a radulafor feeding. B) Both have amantle capable of secreting calcium carbonate. C) Both use siphonsto obtain oxygen. D) Both have sensoryantenna.
20)
If a hiker picked up a mollusk on a trail in a rain forest, what class would it belong to?
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A) Gastropoda B) Polyplacophora C) Bivalvia D) Cephalopoda
21) What change would result for a land snail that had a mutation interfering with chitin formation? A) It would have a soft, demineralized shell. B) It would have difficulty feeding. C) It could not form its exoskeleton. D) Molting would not be possible.
22) Paramecia use cilia for locomotion and for gathering organic matter. How are rotifers similar? A) Rotifers are single-celled protists. B) The corona is made of cilia, and used for swimming and feeding. C) Rotifers and ciliates are thought to have given rise to all other animal phyla. D) Both lack a gut.
23)
Why doesn't a tapeworm have a mouth on its scolex? A) The mouth is on the proglottids. B) Endoparasites don't need a mouth. C) The mouth is located at the end of the pharynx. D) Tapeworms use a radula instead of a mouth to feed.
24) According to the modern classification scheme, which animal would be a spider's closest relative?
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A) A snail B) An earthworm C) A tapeworm D) A roundworm E) A squid
25)
The phylum that includes snails, clams, oysters, and octopuses is the A) Ectoprocta. B) Brachiopoda. C) Mollusca. D) Annelida. E) Phoronida.
26) In mollusks, the folds of tissue that arise from the dorsal body wall and enclose a cavity surrounding the visceral mass are called the A) foot. B) mantle. C) nephridia. D) radula. E) lophophore.
27) Many marine mollusks have distinctive larvae which have their bodies encircled by a row of cilia. These larvae are called A) planulae. B) polyps. C) miracidia. D) zoecia. E) trochophores.
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28)
The organ that is responsible for secreting cocoons in earthworms is known as the A) nephridia. B) setae. C) radula. D) clitellum. E) lophophore.
29)
The Bryozoa and Brachiopoda have which feature in common? A) nephridia B) a lophophore C) a radula D) setae E) a muscular foot
30)
Examples of mollusks that live on land are the A) earthworms. B) land crabs. C) mussels. D) scorpions. E) snails and slugs.
31)
Squids and octopuses move by means of water movement through their A) tentacles. B) cilia and flagella. C) modified mantle cavity. D) muscular foot. E) radula.
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32)
The nitrogenous waste in mollusks is removed by A) flame cells. B) nephridia. C) Malpighian tubules. D) incurrent siphon. E) flagella.
33) Trochophores, the free-swimming larvae of many mollusks, are propelled through the water by A) flagella. B) cilia. C) flame cells. D) nephridia. E) the radula.
34)
Radula modification allowed all of the following functions in gastropods except A) scraping algae off rocks. B) eating vegetation. C) boring holes in other mollusk shells. D) protecting themselves with nematocysts. E) injecting poison through a harpoon-like structure.
35)
Which of the following organs of cephalopods resemble those of the vertebrates?
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A) arms B) nephridia C) eyes D) digestive tissues E) foot
36)
The partitions that separate the segments of the annelid body are known as A) pseudocoels. B) nephridia. C) setae. D) septa. E) radula.
37)
Annelids possess all of the following except A) muscles to swim, crawl, and burrow. B) ganglia to respond to light and respond to other environmental cues. C) circulatory, excretory, and neural elements in each segment. D) setae in each segment. E) adductormuscles.
38)
Each segment of an annelid typically contains bristles of chitin called A) cilia. B) parapodia. C) chaetae. D) leglets.
39)
The sexual reproduction of earthworms characteristically is
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A) hermaphroditic but cross-fertilizing. B) hermaphroditic but self-fertilizing. C) normal type between individuals who remain as males and females throughout their lifetime. D) normal appearing, but individuals change sex periodically. E) normal appearing, but individuals reproduce only once in their lives.
40)
Earthworms show all of the following features except A) containing segments with a mouth on the first and the anus on the last. B) containing touch-sensitive and light-sensitive organs in the segments. C) containing fewer setae than in polychaetes. D) containing distinct head regions and parapodia. E) being hermaphroditic.
41) The medicinal leech, once used to withdraw "unhealthy" blood from patients, produces_________blank to ensure blood flow from the host? A) antibiotics B) antibodies C) anticoagulants D) blood clots E) suture material
42) A biologist has been studying a mollusk that does not have a shell. It lives in the marine environment. Of the examples given below, which one did the biologist study? A) clam B) snail C) nautilus D) chiton E) octopus
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43) All of the following are either structures or characteristics of members of the Class Bivalvia of the Phylum Mollusca except A) the mantle. B) a radula. C) a shell. D) gills. E) open circulation.
44)
Select the mismatched pair of Phylum Mollusca classes and their examples. A) Polyplacophora—chitons B) Gastropoda—slugs C) Bivalvia—snails D) Cephalopoda—nautilus E) Gastropoda—nudibranchs
45) A marine biologist visits your biology class and begins his talk entitled, "Life as a Trochophore." A friend seated next to you asks, "What is a trochophore?" You explain that a trochophore is A) another name for the veliger stage in earthworm reproduction. B) a term used todescribe a larval form of either the phylum Mollusca or Annelida. C) another name for the veliger stage in the oyster. D) similar to a lophophore, but only found in the phylum Annelida. E) a parasite in the intestines of a bivalve mollusk.
46) The evolutionary innovation that first appeared in arthropods and is characteristic of the most successful of all animal groups is that of
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A) bilateral symmetry. B) coelomic body architecture. C) jointed appendages. D) segmentation. E) three primary types of tissues.
47)
In terms of the number of species, the most successful class of arthropods is A) Hexapoda. B) Chelicerata. C) Crustacea. D) Chilopoda. E) Myriapoda.
48) as a
In some arthropods, tagmatization has produced a combination of head and thorax known
A) cephalothorax. B) fused corpora. C) headless mite. D) larval instar. E) thoracotomy.
49)
The passage of an arthropod through stages from egg to adult is A) differentiation. B) evolution. C) graduation. D) metamorphosis. E) succession.
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50)
Nauplius, a unique kind of larva, is characteristic of A) mites. B) crustaceans. C) horseshoe crabs. D) insects. E) chelicerates.
51) it
The rigid chitinous exoskeleton of an arthropod has all of the following functions except
A) provides a place for muscle attachment. B) protects the animal from predators. C) impedes water loss. D) maintains a uniform size for all individuals of that species. E) prevents injury to the animal.
52)
Compound eyes are composed of independent visual units called A) apposition segments. B) ocelli. C) ommatidia. D) retinas. E) simple eyes.
53) Eyes with single lenses that respond to light and darkness are found in many arthropods; these are the
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A) compound eyes. B) ocelli. C) apposition eyes. D) ommatidia. E) superposition segments.
54) Air passage into the trachea of most insects is controlled by the closing and opening of valves, which operate special openings called A) spiracles. B) ocelli. C) ommatidia. D) book lungs. E) Malpighian tubules.
55) The excretory structures of terrestrial arthropods are slender projections from the digestive tract that are attached at the junction of the midgut and hindgut. These are called A) flame cells. B) kidneys and bladders. C) Malpighian tubules. D) nephridia. E) ocelli.
56)
Chelicerae function as A) eyes. B) fangs or pincers. C) jaws or mandibles. D) teeth. E) wings.
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57)
Decapod crustaceans (shrimps, lobsters, and crabs) all lack A) a carapace, a dorsal cephalothorax shield. B) a ventral line of appendages, swimmerets. C) a tail spine, telson. D) chelicerae.
58) An invertebrate biologist is conducting research with crabs. Her interest is ecdysis. This implies that she studies A) tagmatization processes in crustaceans. B) how ommatidia function individually in a compound eye. C) how the HOX gene controls the fusion of the head and thorax into the cephalothorax. D) how ocelli evolved from mere photoreceptors to imaging lens. E) the molting process.
59) A marine biologist makes a presentation about crustaceans to your biology class. He explains that he has recently received an NSF grant to study sessile crustaceans. You are only aware of one group of sessile crustaceans. This crustacean must be A) a lobster. B) a crayfish. C) a shrimp. D) a barnacle. E) the nauplius.
60) Which one of the following incorrectly matches a molluscan structure with its typical function?
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A) ctenidia—secretion of the shell (when present) B) visceral mass—houses organs of digestion, excretion, reproduction C) foot—locomotion D) nephrostome—collection of nitrogenous wastes E) radula—feeding organ
61) Which one of the following incorrectly matches a molluscan group with a feature characterizing that group? A) Gastropoda—torsion B) Nudibranchs—extensive gills in mantle cavity C) Bivalvia—reduced head and no radula D) Polyplacophora—eight calcareous plates E) Cephalopoda—closed circulatory system
62) Which one of the following annelid structures or events is not correctly paired with its role in locomotion? A) circular muscles contract—segment becomes thin and long B) longitudinal muscles contract—segment becomes thick and short C) fluid in coelom—provides a hydrostatic skeleton D) septum—allows each segment to move independently E) chaetae—provides gas exchange surface for body muscles
63)
Which one of the following statements about the phylum Brachiopoda is false? A) Brachiopods are often misidentified as bivalves. B) Brachiopods were much more diverse in the past. C) As in bivalves, the valves in brachiopods are lateral (left and right) to the body axis. D) Most brachiopods are sessile (attached). E) The lophophore resides within the brachiopod's shells.
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64) Which one of the following insect organ systems has placed the greatest limitation on their body size? A) nervous system B) digestive system C) respiratory system D) reproductive system E) excretory system
65)
How does a ribbon worm differ from a flatworm? A) A flatworm has acomplete digestive system. B) A ribbon worm hasa mouth and an anus. C) Flatworms aredeuterostomes. D) Flatworms areradially symmetrical and ribbon worms are bilaterally symmetrical.
66) It is clear that your classmate understands annelid anatomy and physiology well, but flatworms are not so clear. You decide to help by drawing comparisons between structures in the two groups. Although it is less complex, you tell your classmate that the annelid nephridium is similar in function to what flatworm structure? A) Scolex B) Flame cell C) Pharynx D) Proglottid
FILL IN THE BLANK. Write the word or phrase that best completes each statement or answers the question. 67) A_________blank is a circular or U-shaped ridge around the mouth, bearing either one or two rows of ciliated, hollow tentacles.
68)
Brachiopods develop as protostomes, but they show_________blank cleavage.
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69) Members of the class_________blank, which include octopuses, squids, and nautiluses, are highly intelligent.
70) In many arthropods, body segments have become fused into functional groups called_________blank.
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Answer Key Test name: Chap 33_13e_Raven 1) FALSE 2) [B, D, F, G]
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Clarify Question ● What is the key concept addressed by the question?● This question addresses arthropods. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about arthropods?● Spiders are chelicerates and insects are hexapods. They are both arthropods, and both members of Ecdysozoa. ● Spiders have two major body sections, while insects have three. ● All arthropods have a chitinous exoskeleton, and they grow discontinuously at each molt. ● Arthropods have an open circulatory system. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Of the listed options, only these are true for both spiders and insects: ● They have an open circulatory system. ● They have a chitinous exoskeleton. ● They molt. ● They are members of Ecdysozoa. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. Version 1
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● Did you recognize that the arthropods all have a chitinous exoskeleton that is molted, and an open circulatory system? ● Did you remember that the arthropod phylum is part of the larger group Ecdysozoa? 3) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses ecdysis. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content ● What do you already know about ecdysis?● The Ecdysozoa comprises animals that molt. When an animal grows large enough that it completely fills its hard external skeleton, it must lose that skeleton by molting (ecdysis). ● While the animal grows, it forms a new exoskeleton underneath the existing one. The first step in molting is for the body to swell until the existing exoskeleton cracks open and is shed. Upon molting that skeleton, the animal inflates the soft, new one, expanding it using body fluids (and sometimes air). When the new exoskeleton hardens, it is larger than the old one and has room for growth. ● So unlike other animals, the growth of ecdysozoans is step-wise. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Ecdysteroid hormones bind to ecdysteroid receptors to regulate molting. ● So these insecticides kill insects by blocking their ability to molt. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The Version 1
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question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that ecdysteroid hormones and their receptors are essential for insect molting? 4) D 5) D
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Clarify Question ● What is the key concept addressed by the question?● The question is addressing the feature that sets hexapods apart from other arthropods. ● What type of thinking is required?● You are being asked to take what you already know and use, or apply, it to the comparison of hexapods and other arthropods. Gather Content ● What do you already know about hexapods? What other information is related to the question?● Hexapods possess several features that place them in a subgroup of arthropods. ● Insects are hexapods. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● Hexapods exhibit typical arthropod features, but they are the only arthropods with wings. ● Arthropods in general have chitinous exoskeletons and jointed legs. ● Several different groups of arthropods have antennae and mandibles. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Answering this question correctly depended on your ability to recognize hexapods within a group of arthropods. If you got an incorrect answer, did you remember that hexapods include insects, or that hexapods have wings? Did you have trouble extending the features of hexapods to determine the correct answer?
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6) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses crustaceans. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about crustaceans?● A crab is a crustacean, which is a member of the arthropods, part of the Ecdysozoa. ● Like other arthropods, crabs molt periodically, they have an open circulatory system, and they have an external rigid skeleton called the exoskeleton. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Are both vertebrates and arthropods deuterostomes? No. There are a few invertebrates that are deuterostomes, but arthropods like crab are protostomes. ● Do both vertebrates and arthropods have closed circulatory systems? No. Vertebrates have a closed circulatory system, arthropods have an open circulatory system. ● Do both vertebrates and arthropods have a continuous growth pattern? No. Vertebrates do, but arthropods grow in steps at each molt. ● Do both vertebrates and arthropods have muscles that pull against rigid skeletons? Yes! In invertebrates, muscles pull against a rigid endoskeleton of bone; in arthropods, muscles pull against a rigid exoskeleton of chitin. Reflect on Process Version 1
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● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that arthropods like a crab also use muscles against a rigid skeleton? Their skeleton, however, is on the outside – an exoskeleton. 7) D 8) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses insect respiration. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content ● What do you already know about insect respiration?● The insect respiratory system consists of small, branched ducts called tracheae. ● Very small tracheoles allow oxygen and carbon dioxide to diffuse directly into individual cells. ● Since insects depend on the respiratory system (not the circulatory system) to carry oxygen to their tissues, all parts of the body must be near a respiratory passage, limiting their maximum size. ● Air passes into the tracheae through openings in the exoskeleton called spiracles along the thorax and abdomen. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Could the locust be speeding the flow of blood through its veins and arteries? No, because insects do not have veins and arteries – they have an open circulatory system. ● Could the locust be clearing its spinnerets? No, because spiders have spinnerets, but locusts don’t. ● Could the locust be stretching out its pedipalps? No, pedipalps are mouthparts on the head, not the abdomen. ● Could the locust be assisting gas exchange in the tracheal system? Yes. Spiracles are openings to the trachea along the abdomen, and Version 1
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movement of the abdomen can help pump air in and out of the spiracles. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that insects have respiratory openings along their abdomen? 9) A 10) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the lophophore. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about the lophophore?● The two marine phyla Bryozoa and Brachiopoda have a lophophore, a circular or Ushaped ridge around the mouth with one or two rows of ciliated tentacles. ● The lophophore functions as a surface for gas exchange, and the cilia of the lophophore serve to guide the organic detritus and plankton on which the animal feeds to the mouth. ● Because of the lophophore, bryozoans and brachiopods have been considered related to one another, but some recent data indicate that the structures may have evolved convergently. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Lophophores function as both respiratory and feeding structures. ● Their feathery structure provides high surface area for gas exchange. ● In bivalves – mollusks like clams and oysters – a similar structure for gas exchange is the set of internal gills. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The Version 1
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question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the lophophore is both a respiratory and feeding structure? 11) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses earthworm locomotion. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about earthworm locomotion?● The basic annelid body plan is a tube within a tube. ● The coelomic fluid creates a hydrostatic skeleton that gives each segment rigidity, like an inflated balloon. ● Annelids move by contraction of the circular and longitudinal muscles against the hydrostatic skeleton. ● When circular muscles are contracted around a segment, the segment decreases in diameter, so the coelomic fluid causes the segment to elongate. ● When longitudinal muscles contract, the segment shortens, so the coelomic fluid causes the segment to increase in diameter. ● Alternating these contractions and confining them to only some segments allows the worms to move in complex ways. ● In most annelid groups, each segment possesses bristles of chitin called chaetae or setae. By extending the chaetae in some segments so that they protrude into the substrate and retracting them in other segments, the worm avoids slipping. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● To stretch or elongate the body, an annelid contracts the circular muscles around the segment. This causes the segment to get longer. Version 1
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the two sets of muscles in an earthworm – circular and longitudinal – allow it to transform its body in different ways? 12) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses nematode diseases. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about nematode diseases?● About 50 species of nematodes, including ones in the United States, parasitize humans. ● Hookworms suck blood through the intestinal wall, causing anemia. ● Eating undercooked meat can cause trichinosis, an infection of the worm Trichinella, which can sometimes be fatal. ● The intestinal roundworm Ascaris lumbricoides infects approximately one of six people worldwide, but is rare in areas with modern plumbing. ● Filariasis is caused by several species of nematodes that infect at least 250 million people worldwide. Wuchereria bancrofti can cause elephantiasis, in which the lower extremities may swell to disfiguring proportions. The larvae are typically transmitted by a mosquito. ● Pinworms, Enterobius vermicularis, infect 11% of the people in the United States, mainly children. Adult pinworms live in the human rectum where they usually cause nothing more serious than itching of the anus; large numbers, however, can lead to prolapse of the rectum. The worms can easily be killed by drugs. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● A common need for every parasite is the necessity for offspring to travel to a new host. This is achieved in a variety of ways. Some use an intermediate Version 1
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host, like the mosquito. ● In the pinworm, however, the itching symptom induces the host to scratch, carrying eggs on the hands and allowing them to possibly infect a new host. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that causing itching benefits the parasite by helping it to spread? 13) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses lophophorates. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation./li> Gather Content ● What do you already know about lophophorates?● Both Bryozoa and Brachiopoda are phyla of marine organisms with a lophophore, a circular or U-shaped ridge around the mouth with one or two rows of ciliated tentacles. The lophophore functions for gas exchange, and the cilia of the lophophore help bring food to the mouth. ● Because of the lophophore, bryozoans and brachiopods have been considered related to one another, but some recent data indicate that the structures may have evolved convergently. ● Bryozoans are tiny and live in colonies that look like patches of moss on the surfaces of submerged objects. Bryozoans are the only exclusively colonial animals. Each individual bryozoan—a zooid— secretes a tiny chitinous chamber called a zoecium (plural, zoecia) that is attached to rocks or other substrates such as the leaves of marine plants and algae. ● Calcium carbonate is deposited in the wall of a zoecium in many marine bryozoans, and in early geological times, bryozoans formed reefs just as corals do today. A zooid can divide or bud to create asexually another zooid beside the existing one so one wall of the new zooid’s zoecium is shared with that of the existing one; this expanding group of zoecia constitutes a colony. Individuals in the colony communicate chemically through pores between the zoecia. Not all zoecia of a colony may be identical; some are specialized for functions such as feeding, reproduction, or defense. Version 1
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● Brachiopods and phoronids are solitary lophophorates. ● Brachiopods, or lamp shells, superficially resemble clams, but in brachiopods, the valves are dorsal and ventral. Many species attach to rocks or sand by the pedicle (a stalk) that protrudes through an opening in one shell, whereas in others one valve is cemented to the substrate and the animal lacks a pedicle. ● The gut in some brachiopods is U-shaped, as in bryozoans, whereas in others there is no anus at all. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The Bryozoa are always colonial, whereas the brachiopods are solitary. In other words, the zoecia (the shell-like chambers secreted by each bryozoan zooid) are always found in aggregates. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that bryozoans are always colonial, but brachiopods are solitary? 14) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses leeches. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content ● What do you already know about leeches?● Leeches use chitinous, bladelike jaws to make an incision to access blood; they secrete an anticoagulant to keep the blood from clotting. ● Both the anticoagulant and the leech itself have made important contributions to modern medicine. Hirudo medicinalis is the medicinal leech. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● If a leech did not produce normal levels of anticoagulants, when it bit a host, the blood would soon clot and stop flowing. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that leeches produce anticoagulants so that when they bite a host, the blood does not clot?
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15) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses mollusk feeding. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about mollusk feeding?● Gastropods are a type of mollusk – they are the snails and slugs. ● Mollusks feed using the radula – a rasping, tonguelike structure. ● The radula consists of dozens to hundreds of microscopic, chitinous teeth arranged in rows on an underlying membrane and lies in a chamber at the anterior end of the gut. ● The radula can be protruded through the mouth and move something like a sanding belt over what is being rasped. Benthic mollusks use their radulae to scrape up algae and other food materials. ● In some predatory gastropods, the radula is modified to drill through clamshells. In cone snails, the radula has been transformed into a venomous harpoon that can be lethal to humans. ● Bivalves are the only mollusks that have no radula – they use gills to filter food out of the water. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● The beak of an octopus is its feeding structure. ● The feeding structure of a gastropod is the radula. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the radula is the feeding structure of gastropods? Are you surprised to find that slugs and snails have “teeth”? 16) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses annelids. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about annelids?● The annelids comprise two major classes, Errantia (Polychaeta) and Sedentaria (Clitellata) (which combines the old groups Oligochaeta and Hirudinea). ● Errantia (Polychaetes) (“many chaetae”) are marine annelids characterized by numerous bristles or setae/chaetae. ● The Sedentaria (Clitellata) include earthworms and leeches. They have fewer chaetae (setae). (“Oligochaete" means few chaetae.) Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● The most obvious anatomical difference between polychaetes and clitellates is reflected in their former names: polychaetes have more chaetae (setae). Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that Errantia (polychaetes) are “bristly worms”?
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17) C 18) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses cephalopods. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about cephalopods?● The more than 700 species of cephalopods are strictly marine, and typically swift, active predators. ● They are the only mollusks with a closed circulatory system. ● Another difference with many other mollusks is that cephalopods have direct development—that is, they lack a larval stage, hatching as miniature adults. ● The foot has evolved into a series of arms equipped with suction cups, adhesive structures, or hooks that seize prey. ● After snaring prey with its arms, a cephalopod bites the prey with its strong, beaklike jaws, then pulls it into its mouth by the action of the radula. ● Cephalopods have the largest relative brain sizes among invertebrates and highly developed nervous systems. Cephalopod eyes are large and similar to those of vertebrates, although they evolved independently. ● Aside from the chambered nautiluses, living cephalopods lack an external shell. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Which mollusks have direct development (lack a larval stage)? Slug and octopus. Version 1
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● Which mollusk has a closed circulatory system? Octopus. ● Which mollusk has well-developed eyes? Octopus. ● Which mollusk has a large brain? Octopus. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the octopus and other cephalopods have many features unique amongst the mollusks? 19) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses mollusks. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about mollusks?● One of the best-known characters of the mollusk phylum is the shell, which protects against predators and adverse environmental conditions. ● A mollusk shell is secreted by the outer surface of the mantle. ● A typical mollusk shell consists of two layers of calcium carbonate, which is precipitated extracellularly. The outer layer consists of densely packed crystals. In some species, the inner layer is pearly in appearance, and is called mother-of-pearl or nacre. ● Pearls are formed when a foreign object, such as a grain of sand, becomes lodged between the mantle and the inner shell layer. The mantle coats the object with layer upon layer of nacre to reduce the irritation caused by the object. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Do a land snail and an oyster both have a radula for feeding? No. The snail does, but oysters are bivalves – they use their gills to filter feed. ● Do a land snail and an oyster both use siphons to obtain oxygen? No. The oyster does, but in a land snail the mantle acts like a lung ● Do a land snail and an oyster both have sensory antenna? No. Oysters lack these. ● Do a land snail and an oyster both have a mantle capable of secreting Version 1
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calcium carbonate? Yes. This is how they both create their shells. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that both land snails and oysters use their mantles to secrete the calcium carbonate that forms their shells? 20) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses mollusks. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about mollusks?● Mollusks (phylum Mollusca) are morphologically diverse and live in different environments. ● Mollusks include snails, slugs, clams, scallops, oysters, cuttlefish, octopuses, and others. The shells of many mollusks are beautiful and elegant; some mollusks lack a shell. Mollusks range in size from almost microscopic to huge. ● Like all major animal groups, mollusks evolved in the oceans, and most groups have remained there. Marine mollusks are widespread and many are abundant. Snails and slugs have invaded freshwater and terrestrial habitats, and freshwater mussels live in lakes and streams. The flat foot of a snail or slug allows it to crawl on land. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● A rain forest trail is not a typical habitat for a mollusk. Nearly all mollusks are aquatic, and most of them are marine aquatic species. Only one particular group of mollusks has successfully invaded terrestrial environments – the snails and slugs. ● Therefore, it could only be a gastropod. Reflect on Process Version 1
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● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that of all the mollusks, only gastropods are terrestrial? 21) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses mollusk feeding and shell formation. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about mollusk feeding and shell formation?● Gastropods are a type of mollusk – they are the snails and slugs. ● Mollusks feed using the radula – a rasping, tonguelike structure. ● The radula consists of dozens to hundreds of microscopic, chitinous teeth arranged in rows on an underlying membrane and lies in a chamber at the anterior end of the gut. ● The radula can be protruded through the mouth and move something like a sanding belt over what is being rasped. Benthic mollusks use their radulae to scrape up algae and other food materials. ● One of the best-known characters of the mollusk phylum is the shell, which protects against predators and adverse environmental conditions. ● A mollusk shell is secreted by the outer surface of the mantle. ● A typical mollusk shell consists of two layers of calcium carbonate, which is precipitated extracellularly. The outer layer consists of densely packed crystals. In some species, the inner layer is pearly in appearance, and is called mother-of-pearl or nacre. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Without chitin, would a snail have a demineralized shell? No, the hard, mineral component of a mollusk shell is calcium carbonate, not chitin. Version 1
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● Without chitin, would a snail fail to form its exoskeleton? Well, yes, but that is because mollusks do not have an exoskeleton – arthropods do. ● Without chitin, would a snail be unable to molt? Again, technically yes, but, mollusks never molt – arthropods and nematodes do. ● Without chitin, would a snail have difficulty feeding? Yes. The main structure in a snail that is composed of chitin is the radula – the hard, rasping tongue-like structure with which mollusks feed. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the radula of a mollusk is made of chitin? 22) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses rotifers and ciliates. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about rotifers and ciliates?● Rotifers are tiny, bilateral, unsegmented pseudocoelomates. Their ancestors may have resembled flatworms, with which they are classified in the spiralian Platyzoa. ● At 50 to 500 μm long, rotifers are smaller than some ciliate protists. But they have complex bodies with three cell layers, highly developed internal organs, and a complete gut. ● The corona, a conspicuous ring of cilia at the anterior end, is used for locomotion, and its cilia also sweep food into the rotifer’s mouth. Once food is swallowed, it is crushed with a complex jaw in the pharynx. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Like paramecia, rotifers use cilia for both swimming and feeding. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that rotifers use the ciliated corona for both Version 1
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locomotion and feeding? 23) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses tapeworms. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content ● What do you already know about tapeworms?● An adult tapeworm hangs onto the inner wall of its host’s intestine. ● It lacks a digestive cavity as well as digestive enzymes, absorbing food from the host’s gut through its outer surface. ● The long, flat body of a tapeworm is divided into three zones: the scolex, or attachment structure; the neck; and a series of repetitive sections, the proglottids. ● The scolex of many species bears four suckers and may also have hooks. The scolex is not a head: It has neither concentrated nervous tissue nor a mouth. ● Each proglottid is a complete hermaphroditic unit, containing both male and female reproductive organs. Proglottids are formed continuously in a growth zone at the base of the neck, with maturing ones being pushed posteriorly as new ones are formed. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The scolex is not a head, and the tapeworm doesn’t have a mouth anywhere. ● Since the tapeworm is an intestinal parasite, it doesn't need a mouth. It absorbs food directly across its outer surface.
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that endoparasites like tapeworms don’t have a mouth? 24) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses protostome phylogeny. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about protostome phylogeny?● The spider is an arthropod. Arthropods are part of Ecdysozoa – the molting animals. ● The other phyla in Ecdysozoa are: Loricifera, Kinorhyncha, Nematoda, Tardigrada, and Onychophora. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The most common representative of these other ecdysozoan groups is the roundworm – a member of Nematoda. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that arthropods and nematodes are closely related? 25) C 26) B 27) E
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28) D 29) B 30) E 31) C 32) B 33) B 34) D 35) C 36) D 37) E 38) C 39) A 40) D 41) C 42) E 43) B 44) C 45) B 46) C 47) A 48) A 49) D 50) B 51) D 52) C 53) B 54) A 55) C 56) B 57) D Version 1
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58) E 59) D 60) A 61) B 62) E 63) C 64) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses insects. ● What type of thinking is required?● This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. Gather Content ● What do you already know about insects?● The insect respiratory system consists of small, branched ducts called tracheae. ● Very small tracheoles allow oxygen and carbon dioxide to diffuse directly into individual cells. ● Since insects depend on the respiratory system (not the circulatory system) to carry oxygen to their tissues, all parts of the body must be near a respiratory passage, limiting their maximum size. ● Air passes into the tracheae through spiracles which are openings in the exoskeleton along the thorax and abdomen. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The respiratory system of insects does not allow them to grow too big, because oxygen must be able to diffuse to each cell. ● Larger insects could survive in the past when oxygen levels were higher. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The Version 1
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question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. ● Did you recognize that the insect respiratory system places an upper limit on body size, since oxygen must diffuse from the trachea to each cell? 65) B 66) B
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Clarify Question ● What is the key concept addressed by the question?● Comparison of a flatworm structure to an annelid nephridium ● What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to functionally similar structures in annelids and flatworms Gather Content ● What do you already know about flatworm and annelid anatomy? What other information is related to the question?● The annelid nephridium functions in waste removal and in osmotic regulation. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● Flatworms possess an excretory system that also functions in osmoregulation. ● Flame cells move water and waste into the tubules of the excretory system. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Answering this question correctly depended on your ability to compare annelid and flatworm anatomy. If you got an incorrect answer, did you remember that flatworms have excretory and osmoregulatory abilities, and there are structures that provide play similar roles in annelids? 67) lophophore 68) radial
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69) cephalopoda 70) tagmata
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Chapter 34 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) All mammals have hair, mammary glands, and a placenta. ⊚ ⊚
2)
true false
Animals with pentaradial symmetry have 5 planes of symmetry. ⊚ ⊚
true false
CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 3) Your neighbors found a rather rotund toad in the garden, and they excitedly tell you to come and look at this remarkable specimen that they refer to as a reptile. As a biologist, you would like them to understand that this is an amphibian. What features could you highlight in this toad that are present in an amphibian, but not in a reptile? A) Thoracic breathing B) Most species have external fertilization C) Pulmonary and systemic circulation paths D) Cutaneous respiration E) Eggs lack shells and are often laid in water F) Life history may include metamorphosis from a tadpole stage
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 4) What would be an easy way to determine if a skull is a mammal's skull? A) Look for openings in the skull for the attachment of jaw muscles. B) Examine the mouth for specialized teeth. C) Look for the openings for nostrils. D) Look for a hinged jaw.
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5)
Of the primates listed below, a human’s closest extant relative is a(n) A) South American spider monkey. B) mandrill. C) orangutan. D) ring-tailed lemur.
6) For human races to be considered valid biological groupings, the genetic diversity within the group would have to be_________blank the genetic diversity between groups. A) lower than B) equal to C) higher than
7)
The breast meat in a bucket of fried chicken is a muscle that normally allows a bird to A) run. B) jump. C) swim. D) feed. E) fly.
8)
A Tyrannosaurus rex' s closest relative is a A) Komodo dragon. B) bullfrog. C) squirrel. D) chicken.
9) A vertebrate paleontologist is hunting through chalk deposits and finds a set of fused clavicles with some other bone fragments. What has she found?
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A) The remains of anamphibian. B) The remains of a lobe-finned fish. C) The remains of abird. D) The remains of amammal.
10)
What feature do monkeys share with iguanas but not with bullfrogs? A) eyes B) eggs C) thoracic breathing D) four-chambered heart
11)
What would happen to an egg that had a nonfunctional chorion? A) The embryo wouldsuffocate or dehydrate. B) The embryo wouldstarve in the egg. C) The embryo woulddie due to high levels of toxic metabolic wastes. D) The embryo woulddevelop normally.
12)
Which group includes mammals, birds, and reptiles but excludes all other chordates? A) Vertebrates B) Amniotes C) Tetrapods D) Monotremes E) Deuterostomes
13)
Frog eggs most closely resemble
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A) chicken eggs. B) fish eggs. C) platypuseggs. D) alligatoreggs.
14)
Pulmonary veins carry A) oxygenatedblood. B) deoxygenatedblood. C) a mixture ofoxygenated and deoxygenated blood.
15) One of your closest fish relatives is the coelacanth. Where is its equivalent to your forearm? A) The claspers B) The pectoral fin lobe C) The operculum D) The gill arch extensions E) The pelvic fin lobe
16) Sharks have a number of fleshy gill slits instead of a bony gill cover. How does this affect their behavior? A) Their movements are slow due to low oxygen. B) They live only in highly oxygenated water. C) They keep swimming to move water across their gills. D) They do not maintain neutral buoyancy.
17) Scuba divers use a BCD to control buoyancy. It is essentially a bag that can be inflated or deflated to prevent excessive sinking or floating. How do bony fish accomplish this?
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A) They pump their operculum. B) They adjust the level of gasses in their swim bladder. C) They adjust their position using the pectoral and pelvic fins. D) They swim rapidly to saturate the blood with oxygen.
18) A tunicate looks like a sponge. How could a biologist distinguish it from a member of the Porifera? A) Tunicates do not filter feed. B) Only tunicatesproduce gametes. C) Unlike tunicates,sponges are symmetrical. D) Tunicates have a stomach.
19) Manta rays, sting rays, and eagle rays are similar to lampreys in that they have cartilaginous skeletons. How are they different from lampreys? A) They have closedcirculatory systems. B) They havegills. C) They havejaws. D) They have bonyfin lobes.
20)
If an adult human suffered a traumatic injury, could their notochord be damaged? A) Yes; because thenotochord is deep within the body only a severe injury could damage
it. B) No; the notochordis encased in bone and it not susceptible to damage. C) Yes; damage tothe notochord often results in paralysis. D) No; adult humansdo not have a notochord.
21)
What best describes the tunic of a tunicate?
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A) It is made of chitin, like the shell of a crab. B) It is made of calcium carbonate, like the shell of a clam. C) It is made of keratin, like human hair. D) It is made of cellulose, like the cell wall of a plant.
22)
When a tourist buys a sand dollar at a beach shop, what are they buying? A) A calcium carbonate shell secreted from the mantle B) An endoskeleton of calcium carbonate ossicles C) A molted exoskeleton made of chitin D) An endoskeleton made of bone E) An endoskeleton made of cartilage
23) In the lab, you observe that a mucous sheet produced by the endostyle in the pharynx of an animal traps the microscopic food particles in the water. What animal are you observing? A) arrow worm B) tunicate C) acorn worm D) lancelet E) crinoid
24) Small, fishlike marine chordates, pointed at both ends with no distinguishable head, in which the notochord runs the entire length of the nerve cord, are called A) arrow worms. B) tunicates. C) acorn worms. D) lancelets. E) lampreys.
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25)
Most bony fishes have a hard plate that covers the gills on each side of the head called the A) radula. B) pharyngeal slits. C) lateral lines. D) operculum. E) gill arches.
26) One of the most critical adaptations of the reptiles in relation to their life on land is the evolution of the A) amniotic egg. B) allantois egg. C) chorionic egg. D) diploid egg. E) swim bladder.
27) Birds, like mammals, can regulate their body temperatures within close limits. Therefore birds and mammals are called A) ectothermic. B) poikilothermic. C) endothermic. D) heterothermic.
28) Which of the following is considered the key innovation that started chordates along the evolutionary path that led to vertebrates?
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A) a flexible rod to which muscles are attached, which allowed lateral movement of the back B) an internal endoskeleton C) a skin covering the entire body to prevent desiccation D) a hard shell encasing the body E) amniotic egg
29)
In addition to a vertebral column, all vertebrates have A) a distinctive head or skull. B) an open circulatory system. C) gills. D) scales. E) a tunic.
30) It is generally accepted that the vertebrates that evolved during the early Devonian period are the A) sharks and bony fish. B) hominoids. C) birds. D) dinosaurs. E) mammals.
31)
Amphibians are thought to have evolved from A) ray-finned fish. B) lobe-finned fish. C) spiny fish. D) skates and rays. E) annelids.
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32)
Amphibians are not completely free to live on dry land because A) they lay amniotic eggs. B) their food organisms live in water. C) their reproduction depends on water. D) they can escape from predators by jumping into the water. E) they only have a partially-divided heart.
33) Features that have been retained by reptiles from the time they replaced the amphibians as the dominant terrestrial vertebrates include all of the following, except A) the amniotic egg. B) dry skin. C) thoracic breathing. D) reoriented appendages. E) endothermy.
34)
Reptiles can maintain their internal body temperature by A) behavioral mechanisms. B) drinking warm or cool water. C) eating and oxidizing more food. D) an effective insulating covering. E) rerouting blood to distribute heat.
35) Which of the following living reptiles care for their young and have a four-chambered heart, as birds do?
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A) turtles B) crocodiles C) lizards D) snakes E) tuataras
36) In terms of number of species, the most successful terrestrial vertebrates that invaded the air are A) insects. B) pterosaurs. C) birds. D) bats. E) flying monkeys.
37) The changes that were necessary to cope with the heavy energy demands of flight in birds include all of the following except A) efficient respiration. B) efficient circulation. C) endothermy. D) auxiliary air sacs and hollow bones. E) a three-chambered heart.
38)
Mammals are thought to have evolved from A) thecodonts. B) therapsids. C) dinosaurs. D) marsupials. E) archosaurs.
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39)
Mammals are the only vertebrates to possess A) hair. B) single loop circulation. C) a four-chambered heart with a pulmonary circuit. D) endothermy. E) live birth.
40)
Monotremes differ from the other mammals in their A) laying of shelled eggs. B) lack ofmilk-producing glands. C) fur. D) carnivorous nature. E) containing a pouch for young to live.
41)
The only marsupial mammal living in North America is the A) opossum. B) raccoon. C) ring-tailed cat. D) weasel. E) wombat.
42) The key specializations that occurred in the evolution of mammals include all of the following except
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A) warm-bloodedness. B) the presence of a placenta in most. C) different teeth suited to their diet. D) digestive tract specialization. E) reduction in brain size.
43)
If a human lacks pharyngeal pouches, what would not form? A) Esophagus B) Trachea C) Eustachian tube D) Bronchial tube E) Pharynx
44)
Which of the following statements about tunicates is incorrect? A) Tunicates are nonvertebrate chordates. B) Tunicates are all marine animals. C) Tunicates are sessile as adults. D) Tunicate larvae are tadpole-like with all of the basic chordate characteristics. E) Tunicate larvae can reproduce.
45)
The following classes of fish are matched with an example. Select the mismatched pair. A) Chondrichthyes—sharks B) Placodermi—lobe-finned fish C) Myxini—hagfish D) Actinopterygii—ray-finned fish
46) Bony fishes possess two features not found in other fish. Select the best choice from those listed below to complete the following sentence. Bony fishes have
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A) swim bladders andgill covers called opercula. B) swim bladders anda complete digestive system. C) swim bladders anda closed circulatory system. D) swim bladders andmovable jaws.
47) A friend of yours visited a natural history museum that had a replica of the Archaeopteryx. She told you the characteristics of Archaeopteryx that she either noticed or read at the display. Which one did she misread? A) Archaeopteryx had feathers, as do modern birds. B) Archaeopteryx lacked teeth, as do modern birds. C) Archaeopteryx had solid bones, unlike the hollow bones of modern birds. D) Archaeopteryx had wings as do modern birds. E) Archaeopteryx had a long tail, unlike modern birds.
48) Because of its association with tools, the earliest human was called_________blank meaning "handy man." A) Homo habilis B) Homo erectus C) Homo sapiens D) Neanderthal E) Cro-Magnon
49) Fossils of our own species,_________blank, that are as much as 100,000 years old, have been found in Africa. A) Homo habilis B) Homo erectus C) Homo sapiens D) Homo hominis E) Homo australopithecus
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50)
The European Neanderthals were replaced about 34,000 years ago by A) Homo habilis. B) Homo erectus. C) Homo heidelbergensis. D) Neanderthals. E) Cro-Magnons.
51)
All of the following features are true of primates except A) they are mammals with grasping fingers and toes. B) they belong to the order containing lemurs, monkeys, and apes. C) they have binocular vision. D) young are born as embryos and complete development in an external pouch.
52)
All of the following features are true of Anthropoids except A) they include monkeys, apes, and humans. B) almost all were diurnal. C) opposable thumbs. D) living in groups with complex social interactions. E) changes to eye design and increase in brain size.
53)
All of the following are true about prosimians except A) they are big-eyedmammals with increased visual acuity. B) only two lineages survive today. C) they are nocturnal. D) they are widespread.
54)
New world monkeys have all of the following features except
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A) they have flat spreading noses. B) they grasp objects with long prehensile tails. C) they evolved in isolation in South America. D) they are all arboreal. E) they have ischial callosities (thickened rump pads).
55)
Apes and humans together make up a group called A) hominids. B) hominoids. C) Homo sapiens. D) habilis. E) prosimians.
56)
DNA studies can be used to make all of the following conclusions except that A) The gibbon apeline diverged about 15 million years ago. B) Orangutans splitoff about 10 million years ago. C) The gorillalineage diverged about 8 million years ago. D) Modern manremained changeless for the last 1 million years.
57)
Modern humans share the greatest similarities with which one of the hominids? A) Australopithecines B) Neanderthals C) Cro-Magnons D) Prosimians E) Primates
58) Which of the following evidence obtained from fossil studies is generally accepted as marking the beginning of the hominids? Version 1
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A) large brain development B) walking upright C) bipedalism D) development of lower limbs longer than forelimbs E) manufacture and use of tools
59) The hominid australopithecines are generally accepted to be different from modern humans because A) only humans are bipedal. B) the human skull is apelike in appearance with a strongly projecting face. C) human brains on an average are at least twice as large in size. D) human arms are longer than legs. E) only humans are meat-eaters.
60)
All of the following about Homo habilis is true except A) the species lived in Africa for 500,000 years and then became extinct. B) the species coexisted with dinosaurs. C) the species was replaced by a new kind of human, which had a larger brain. D) the species was small in stature. E) the species was associated with tools.
61)
Homo erectus has been shown to have dispersed from A) Africa. B) Asia. C) South America. D) Europe. E) North America.
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62)
Homo erectus and the modern humans differ in A) social behavior. B) living as tribes. C) their brain size. D) their upright posture. E) opposable thumbs.
63)
Anthropoids or higher primates include all of the following except A) New World monkeys. B) Old World monkeys. C) apes. D) humans. E) lemurs.
64) New World monkeys evolved approximately 30 million years ago. These animals are easy to identify because they A) have opposable thumbs and binocular vision. B) have prehensile tails and hair. C) have protruding noses and prehensile tails. D) have flattened noses and prehensile tails. E) have opposable thumbs and protruding noses.
65)
One characteristic that New World monkeys have that Old World monkeys lack is A) binocular vision. B) opposable thumbs. C) hair covering their bodies. D) prehensile tails. E) females have mammary glands.
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66) Apes and monkeys differ in two noticeable characteristics. These characteristics are that apes have A) opposable thumbs and monkeys do not, and apes have binocular vision and monkeys do not. B) opposable thumbs and monkeys do not, and apes have tails and monkeys do not. C) binocular vision and monkeys do not, and apes have tails and monkeys do not. D) larger brains than monkeys do, and monkeys have tails and apes do not. E) opposable thumbs and monkeys do not, and monkeys have larger brain capacity than apes do.
67)
Which of the following has the longest fossil record? A) Homo sapiens B) Homo erectus C) Homo habilis D) Homo neanderthalensis E) Homo heidelbergensis
68) Of the following sequences, which one reflects the best scientific knowledge about the succession of Homo species from the past until the present? A) Homo heidelbergensis → Homohabilis → Homo sapiens → Homo erectus B) Homo habilis → Homoheidelbergensis → Homo erectus → Homo sapiens C) Homo heidelbergensis → Homosapiens → Homo erectus → Homo habilis D) Homo sapiens → Homoheidelbergensis → Homo habilis → Homo erectus E) Homo habilis → Homoerectus → Homo heidelbergensis → Homo sapiens
69)
Which one of the following structures is not found in all adult and larval tunicates?
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A) incurrent siphon B) excurrent siphon C) gill slits D) notochord E) pharynx
70) Which one of the following incorrectly pairs a vertebrate group with its major evolutionary innovation? A) Amphibians—paired lateral fins B) Dinosaurs—bipedalism C) Placoderms—jaws D) Sharks—teeth E) Ostracoderms—cartilaginous endoskeleton
71) To which group of fishes does the following description apply: swim bladder, bony skeleton, and paired fins supported by bony rays. A) Sarcopterygi B) Actinopterygii C) Chondrichthyes D) Placodermi E) Acanthodii
72)
Which one of the following was not an adaptation seen in the sharks (Chondrichthyes)? A) lateral line system B) internal fertilization and internal development C) swim bladder D) teeth E) calcified cartilaginous skeleton
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73) You dissect a specimen of a vertebrate during an anatomy laboratory. It has the following characteristics: lungs, abundant blood capillaries under thin skin, a partially-divided heart, a pulmonary circuit, and four walking legs. What is this animal? A) lungfish B) amphibian C) reptile D) placental mammal E) marsupial mammal
74) The invasion of the land by amphibians posed a number of challenges requiring evolutionary innovations. Which one of the following does NOT match a challenge with a corresponding adaptation found in amphibians? A) The force of gravity was greater without water's buoying effect, selecting for wellmuscled legs. B) Additional oxygen was needed for larger muscles, selecting for the partially-divided heart and pulmonary circuit. C) Eggs dry out in a terrestrial environment, selecting for the amniotic egg. D) Gills tend to collapse out of the water, selecting for lungs and cutaneous respiration.
75) Which one of the following does not match a component of the amniotic egg with its primary function? A) shell—porous, protective covering B) chorion—exchange of respiratory gases; retention of water C) amnion—encloses embryo within an oxygen-filled cavity D) allantois—segregates nitrogenous wastes from embryo E) yolk sac—provides food for the embryo
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76) You excavate a fossil of a small reptile during a paleontology field trip. It has the following characteristics: a skull with a pair of dorsal temporal openings and a pair of lateral temporal openings; bipedal with legs positioned directly under the pelvic girdle. Dating with radioisotopes shows that the specimen lived 100 million years ago (MYA). Do you conclude that the specimen belongs to which reptilian group (be specific as possible)? A) anapsid B) synapsid C) diapsid D) archosaur E) dinosaur
77)
Which of the following is NOT a bird adaptation that facilitates flight? A) hollow bones and air sacs B) bipedalism C) reduction in size of the breast muscles D) changes in the forearm bones E) feathers F) fused bones
78)
Which one of the following is not an adaptation shown by modern birds? A) a respiratory system that allows all of the air to pass through the lungs in one direction B) complete division of the heart into right and left halves C) endothermy D) wings and a long feathered tail E) modified beaks and feet to support feeding behavior
79) Which one of the following is the least likely reason that bipedalism evolved in hominins?
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A) requires less energy than walking with all four legs B) frees the hands for tool-making C) frees the hands for carrying food to be shared with others D) allows better surveillance for predators E) increases access to food resources
80)
Sea stars belong to the A) Asteroidea. B) Holothuroidea. C) Echinoidea. D) Crinoidea.
81)
What do echinoderms and chordates have in common? A) endoskeletons B) dorsal nervecords C) protostomedevelopment D) ecdysis
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Answer Key Test name: Chap 34_13e_Raven 1) FALSE 2) TRUE 3) [B, D, E, F]
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Clarify Question ● What is the key concept addressed by the question?● Amphibian characteristics ● What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to the comparison of amphibians and reptiles. Gather Content ● What do you already know about amphibian characteristics? What other information is related to the question? ● Amphibians are often more closely tied to water in their life history patterns. ● Amphibians practice cutaneous respiration. ● Amphibians have systemic and pulmonary circuits. ● Amphibians tend to lay eggs in water. ● Amphibians usually utilize external fertilization. ● Amphibians may metamorphose from tadpole to adult. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer? ● Thoracic breathing is characteristic of reptiles but not amphibians. ● Most amphibians do have external fertilization, but reptiles do not. ● Amphibians and reptiles have systemic and pulmonary circuits. ● Amphibians use cutaneous respiration, but reptiles cannot breathe through their skin. ● Amphibians often lay non-shelled eggs in water, but reptiles lay amniotic eggs on land. ● Many amphibians include a tadpole stage and metamorphosis in their life cycle, but reptiles do not exemplify this process. Reflect on Process Version 1
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● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use amphibian characteristics in a new situation… If you got an incorrect answer, did you remember that amphibians are usually closely tied to water, or that they can breathe through their skin? Did you have trouble extending amphibian characteristics to determine the correct answer? 4) B
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Clarify Question ● What is the key concept addressed by the question? ● Characteristics of the mammalian skull ● What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to the identification of a mammalian skull. Gather Content ● What do you already know about mammalian skulls? What other information is related to the question? ● A mammal is a tripod and an amniote and so shares several characteristics with other animal groups. Identifying a mammalian skull requires focusing on features unique to mammals. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● Mammals have an opening in the skull but other amniotes also have openings. ● Mammals have openings for nostrils and a hinged jaw but so do other tetrapods. ● Mammals have specialized teeth while animal groups have teeth but do not exhibit a specialization of teeth. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use the characteristics of the mammalian skull in a new situation… If you got an incorrect answer, did you remember that mammals have different types of teeth, or that the other features would not be identifying features for Version 1
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mammals? Did you have trouble extending the characteristics of the mammalian skull to determine the correct answer? 5) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses primate relationships. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about primate relationships?● The primates consist of several groups. ● Tarsiers, lemurs, and lorises used to be considered prosimians, but it is now realized that this group is paraphyletic, with tarsiers more closely related to monkeys and apes than they are to lemurs and lorises. ● Anthropoids include monkeys, apes, and humans. ● The monkeys fall into two groups, New World monkeys and Old World monkeys. The mandrill, despite its short tail, is an Old World monkey, not an ape. ● Anthropoids that remained in Africa gave rise to two lineages: the Old World monkeys and the hominoids (apes and humans). ● The apes include gibbons, orangutans, gorillas, and chimpanzees. The chimpanzees and hominids (humans and human ancestors) are sister groups. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● The ring-tailed lemur is the most distantly related to humans. It lies at the base of the primate phylogeny, in the clade of lemurs and lorises. ● The South American spider monkey is the second most distant from humans. It is a New World monkey. ● The mandrill is still distantly related to humans. It is an Old World Version 1
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monkey, not an ape. ● The orangutan is a hominoid and an ape. Of these options, it is the closest relative to humans. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that mandrills are Old World monkeys, not apes? 6) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the human race. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content ● What do you already know about the human race?● Humans have differentiated in their characteristics as they have spread throughout the world. For example, northern Europeans often have blond hair, fair skin, and blue eyes, whereas Africans often have black hair, dark skin, and brown eyes. These traits may play a role in adapting the particular populations to their environments. ● All humans are capable of mating with one another and producing fertile offspring. The reasons that they do or do not choose to associate with one another are purely psychological and behavioral (cultural). ● The number of groups into which the human species might logically be divided has long been a point of contention. Some contemporary anthropologists divide people into as many as 30 “races,” others as few as three. ● The characteristics used to define the races are usually not well correlated with one another, and so the determination of race is always somewhat arbitrary. Indeed, if one were to break the human species into subunits based on overall genetic similarity, the groupings would be very different from those based on skin color or other visual features. ● In humans, it is not possible to delimit clearly defined races that reflect biologically differentiated and well-defined groupings. Relatively little variation in the human species represents differences between the described races. The human racial categories do a very poor job in Version 1
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describing the vast majority of genetic variation that exists in humans. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Human races are not valid biological groupings. The reason is simple: Different groups of people have constantly intermingled and interbred with one another during the entire course of history. This constant gene flow has prevented the human species from fragmenting into highly differentiated subspecies. ● To be a valid grouping, each race would have to have less genetic variability within it than between races. But in fact, this is not the case. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that the human races are not valid biological groupings, because there is so much genetic overlap between them? People of different races may have less genetic variability than people of the “same” race. 7) E
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Clarify Question ● What is the key concept addressed by the question?● This question addresses bird adaptations. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about bird adaptations?● Birds have several adaptations for flight. ● The bones of birds are thin and hollow. Many of the bones are fused, making the bird skeleton more rigid than a reptilian skeleton. The fused sections of the backbone and of the shoulder and hip girdles form a sturdy frame that anchors muscles during flight. ● The power for active flight comes from large breast muscles that can make up 30% of a bird’s total body weight. They stretch down from the wing and attach to the breastbone, which is greatly enlarged and bears a prominent keel for muscle attachment. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● The large breast muscles of a bird are the muscles that power the wings in flight. ● Chickens can fly, although not well because they have been selected to put on extra mass. However, they still have large flight muscles that we call “breast meat”. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that breast meat is really the bird’s flight muscles? 8) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses reptile-bird relationships. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about reptile-bird relationships?● The first known bird was Archaeopteryx, a 150-million-year-old fossil. It had a skull with teeth, and very few of its bones were fused to one another. Its bones are thought to have been solid, not hollow like a bird’s. Also, it had a long, reptilian tail and no enlarged breastbone such as modern birds use to anchor flight muscles. Finally, the skeletal structure of the forelimbs was nearly identical to those of theropods. ● Because of its many dinosaur features, several Archaeopteryx fossils in which the feathers had not been preserved were originally misclassified as a small theropod dinosaurs. However, it in fact had feathers on its wings and tail. ● Almost all paleontologists have concluded that Archaeopteryx is the direct descendant of dinosaurs—indeed, that today’s birds are “feathered dinosaurs.” ● The dinosaur Caudipteryx, for example, is clearly intermediate between Archaeopteryx and dinosaurs, having large feathers on its tail and arms but also many features of dinosaurs like Velociraptor. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● The closest extant relative to the dinosaurs are the birds. ● Therefore the chicken is the correct option. Version 1
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that birds evolved from a group of dinosaurs? 9) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses bird adaptations. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about bird adaptations?● Birds have several adaptations for flight. ● The bones of birds are thin and hollow. Many of the bones are fused, making the bird skeleton more rigid than a reptilian skeleton. The fused sections of backbone and of the shoulder and hip girdles form a sturdy frame that anchors muscles during flight. ● The power for active flight comes from large breast muscles that can make up 30% of a bird’s total body weight. They stretch down from the wing and attach to the breastbone, which is greatly enlarged and bears a prominent keel for muscle attachment. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Birds are the group of vertebrates known for fused bones. The fused sections of backbone and of the shoulder and hip girdles form a sturdy frame that anchors muscles during flight. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this Version 1
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unfamiliar situation. ● Did you recognize that birds have many fused bones to help them fly? 10) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses reptile innovations. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about reptile innovations?● All living reptiles share certain fundamental characteristics that were innovations not seen in their amphibian relatives. These innovations include amniotic eggs, dry skin, and thoracic breathing. Furthermore, their hearts became more efficient – although only one group of reptiles evolved a four-chambered heart. ● Amniotic eggs: Most reptiles lay watertight eggs that contain yolk and a series of four membranes. All modern reptiles, as well as birds and mammals, share these membranes and are called amniotes. ● Dry skin: Reptiles have dry, watertight skin with a layer of scales that reduces water loss. ● Thoracic breathing: Amphibians breathe by squeezing their throat to pump air into their lungs; this limits their breathing capacity to the volume of their mouths. Reptiles developed pulmonary breathing, expanding and contracting the rib cage and diaphragm to suck air into the lungs and then force it out. The capacity of this system is limited only by the volume of the lungs. ● Heart chambers: The circulatory system of reptiles is an improvement over that of fish and amphibians, providing oxygen to the body more efficiently. The improvement is achieved by extending the septum within the heart from the atrium partway across the ventricle. This septum creates a partial wall that tends to lessen the mixing of oxygen-poor blood with oxygen-rich blood within the ventricle. Version 1
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Crocodiles independently evolved a fully four-chambered heart, like that in birds and mammals, by extending the septum to completely divide the ventricle. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Do monkeys and iguanas, but not bullfrogs, have eyes? No, they all have eyes. ● Do monkeys and iguanas, but not bullfrogs, have eggs? No, iguanas and bullfrogs both lay external eggs, ● Do monkeys and iguanas, but not bullfrogs, have a four-chambered heart? No. The monkey has a four-chambered heart, but the heart of an iguana is like those of most other reptiles (besides crocodiles) – the septum does not completely cross the ventricle to create four chambers. ● Do monkeys and iguanas, but not bullfrogs, have thoracic breathing? Yes, thoracic breathing was a new innovation in the reptiles, not found in the amphibians, and was maintained in the mammals. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that one of the innovations of reptiles was thoracic breathing? 11) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the amniotic egg. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content ● What do you already know about the amniotic egg?● Amphibians’ eggs must be laid in water or a moist setting to avoid drying out. Most reptiles lay watertight eggs that contain a food source (the yolk) and a series of four membranes: the yolk sac, the amnion, the allantois, and the chorion. Each membrane plays a role in making the egg an independent life-support system. All modern reptiles, as well as birds and mammals, show exactly this same pattern of membranes within the egg. These three classes are called amniotes. ● The outermost membrane of the egg is the chorion, which lies just beneath the porous shell. It allows the exchange of respiratory gases but retains water. ● The amnion encases the developing embryo within a fluid-filled cavity. ● The yolk sac provides food from the yolk for the embryo via blood vessels connecting to the embryo’s gut. ● The allantois surrounds a cavity into which waste products from the embryo are excreted. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● The function of the chorion is to allow gases to pass in and out of the egg, Version 1
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but to retain water, So if there was a problem with the chorion, the embryo would either suffocate or dehydrate. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that the chorion is the outermost membrane of the amniotic egg, and it allows gas in and out but keeps water in? 12) B
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Clarify Question ● What is the key concept addressed by the question?● Common features of reptiles, birds, and mammals ● What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to assembling a group composed of mammals, birds, and reptiles based on shared features. Gather Content ● What do you already know about features that are shared by reptiles, birds, and mammals? What other information is related to the question? ● These creatures share the designation of vertebrate, chordate, deuterostome, and tetrapods with amphibians. ● Amphibian eggs are not amniotic. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer? ● The eggs of reptiles, birds, and mammals are amniotic. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use the common features of reptiles, birds, and mammals in a new situation… If you got an incorrect answer, did you remember that all of the specified animals are amniotes and that the other features are shared by animals outside of this group? 13) B Version 1
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Clarify Question ● What is the key concept addressed by the question?● This question addresses eggs. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about eggs?● Both fish and amphibians’ eggs must be laid in water or a moist setting to avoid drying out. ● Most reptiles lay watertight “amniotic” eggs: eggs that contain yolk and a series of four membranes. All modern reptiles, as well as birds and mammals, share these membranes and are called amniotes. ● Each membrane of the amniotic egg plays a role in making the egg an independent life-support system. The outermost membrane of the egg is the chorion, which lies just beneath the porous shell. It allows the exchange of respiratory gases but retains water. The amnion encases the developing embryo within a fluid-filled cavity. The yolk sac provides food from the yolk for the embryo via blood vessels connecting to the embryo’s gut. The allantois surrounds a cavity into which waste products from the embryo are excreted. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Because both fish and amphibians lack the features of the amniotic egg, their eggs are more similar to each other than to eggs of any of the amniotes (reptiles, birds, and mammals). Reflect on Process ● Did your problem-solving process lead you to the correct answer? Version 1
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If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that fish and amphibian eggs lack the innovations of the amniotic egg? 14) A 15) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the coelacanths. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about the coelacanths?● The two major groups of bony fish differ in the structure of their fins: the ray-finned fishes and the lobe-finned fishes. ● In ray-finned fishes, the internal skeleton of the fin is composed of parallel bony rays that support and stiffen each fin. There are no muscles within the fins -- they are moved by muscles within the body. ● By contrast, coelacanths have paired fins that consist of a long fleshy muscular lobe supported by a central core of bones that form fully articulated joints with one another. There are bony rays only at the tips of each lobed fin. Muscles within each lobe can move the fin rays independently. ● Lobe-finned fish evolved 390 mya, shortly after the first bony fishes appeared. Only eight species survive today, two species of coelacanth (subclass Actinistia) and six species of lungfish (subclass Dipnoi). Although rare today, lobe-finned fishes played an important part in the evolutionary story of vertebrates because it was a coelacanth that crawled out of the water and colonized land, giving rise to the first amphibians. Lungfish are more closely related to tetrapods (legged vertebrates) than they are to coelacanths, thus making the Sarcopterygii a paraphyletic group. Choose Answer ● Given what you now know, what information and/or problemVersion 1
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solving approach is most likely to produce the correct answer?● The coelacanth’s lobed fins represent the limbs that evolved into the amphibian legs. ● So the pectoral lobe fins (toward the front of the coelacanth’s body) would be homologous to your forearms. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the coelacanth lobe fins are homologous to your arms and legs? 16) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the operculum. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about the operculum?● Most bony fishes have a hard plate called the operculum, or gill cover, that covers the gills on each side of the head. Sharks lack an operculum. ● In bony fish, flexing the operculum pumps water over the gills. The gills are suspended in the pharyngeal slits that form a passageway between the pharynx and the outside of the fish’s body. When the operculum is closed, it seals off the exit. When the mouth is open, closing the operculum increases the volume of the mouth cavity, so that water is drawn into the mouth. When the mouth is closed, opening the operculum decreases the volume of the mouth cavity, forcing water past the gills to the outside. Using this very efficient bellows, bony fishes can pass water over the gills while remaining stationary in the water. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Since sharks lack an operculum (or gill cover), they keep moving to keep oxygenated water passing over the gills. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The Version 1
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question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that the reason sharks must keep moving for respiration is because they lack an operculum, or gill cover? 17) B 18) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses tunicates. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about tunicates?● Tunicates are members of the subphylum Urochordata. Their morphology is simple on the outside, but more complex on the inside. ● Water enters through the incurrent siphon and exits through the excurrent siphon. The pharynx is lined with cilia that draw a stream of water into the pharynx, where microscopic food particles become trapped in a mucous sheet secreted from a structure called an endostyle. Captured food particles pass into the stomach and through the intestine. ● Tunicates change so much as they mature and adjust developmentally to an immobile, filter-feeding existence that it is difficult to discern their evolutionary relationships solely by examining an adult. Many adult tunicates secrete a tunic, a tough sac composed mainly of cellulose, a substance frequently found in the cell walls of plants and algae but rarely found in animals. The tunic surrounds the animal and gives the subphylum its name. Colonial tunicates may have a common sac and a common opening to the outside. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Sponges are morphologically simple on the outside and the inside, but tunicates have a gut and stomach inside. The stomach, therefore, identifies the sponge-like animal as a member of the Urochordata. Version 1
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that tunicates have a full digestive tract inside? 19) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the evolution of the jaw. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about the evolution of the jaw?● An important evolutionary advance in the late Silurian was the development of jaws. Jaws evolved from gill arches, which in jawless fish were cartilaginous struts used to reinforce the tissue between gill slits to hold the slits open. ● Each gill arch was formed by a series of several cartilages (which later evolved to become bones) arranged somewhat in the shape of a V turned on its side, with the point directed outward. Imagine the fusion of the front pair of arches at top and bottom, with hinges at the points, and you have the primitive vertebrate jaw. ● Armored fishes called placoderms and spiny fishes called acanthodians both had jaws. Spiny fishes and ostracoderms had internal skeletons made of cartilage, but their scales contained small plates of bone. Spiny fishes were jawed predators and far better swimmers than ostracoderms, with many fins reinforced with strong spines. ● The diverse and successful placoderms dominated the seas of the late Devonian. The placoderm jaw was much improved over the primitive jaw of spiny fishes, with the upper jaw fused to the skull and the skull hinged on the shoulder. ● At the end of the Devonian period, these pioneer vertebrates were replaced by sharks and bony fishes. ● In these fishes, the jaw was improved even further, with the upper part of the first gill arch behind the jaws being transformed into a supporting Version 1
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strut or prop, joining the rear of the lower jaw to the back of the skull. This allowed the mouth to open much wider than was previously possible. Soon, sharks became the dominant predators in the sea. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Like their relatives the sharks, rays have jaws. Lampreys do not. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that a major innovation of the cartilaginous fish was the refinement of the jaw? 20) D
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the notochord. ● What type of thinking is required?● This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. Gather Content ● What do you already know about the notochord?● One of the features that characterizes the chordates is the notochord. ● The notochord is a flexible rod that forms on the dorsal side of the primitive gut in the early embryo and is present at some developmental stage in all chordates. The notochord is located just below the nerve cord. The notochord may persist in some chordates; in others it is replaced during embryonic development by the vertebral column that forms around the nerve cord. ● During development of the vertebra, the flexible notochord is surrounded and eventually replaced by a cartilaginous or bony covering, the centrum. The neural tube is protected by an arch above the centrum. The vertebral column functions as a strong, flexible rod that the muscles pull against when the animal swims or moves. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Adult humans do not have a notochord. It is replaced by the vertebral column during embryonic development. Reflect on Process ● Did your problem-solving process lead you to the correct answer? Version 1
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If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. ● Did you recognize that in humans, the notochord is a feature only of the developing embryo? 21) D 22) B
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Clarify Question ● What is the key concept addressed by the question? ● Sand dollar anatomy ● What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to recognizing sand dollar anatomy in an unfamiliar setting. Gather Content ● What do you already know about sand dollar anatomy? What other information is related to the question? ● Sand dollars are echinoderms. ● Echinoderms have endoskeletons. ● The endoskeleton is made of calcareous plates called ossicles. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer? ● Mantles that secrete shells are characteristic of mollusks, not echinoderms. ● Echinoderms have endoskeletons, not exoskeletons. ● The echinoderm endoskeleton is done not consist of bone or cartilage. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use sand dollar anatomy in a new situation… If you got an incorrect answer, did you remember that sand dollars are echinoderms, or that echinoderms have calcareous endoskeletons? Did you have trouble extending sand dollar anatomy to determine the correct answer? 23) B Version 1
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Clarify Question ● What is the key concept addressed by the question? ● The endostyle is a characteristic feature ● What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to the recognition of an animal-based on the endostyle Gather Content ● What do you already know about the endostyle? What other information is related to the question? ● The endostyle is characteristic of chordates. ● Adult urochordates are known for their large pharynx and filter feeing abilities. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● Tunicates are urochordates with a pharynx and an endostyle that secretes mucus for food capture. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use the endostyle in a new situation… If you got an incorrect answer, did you remember that an endostyle is a characteristic of chordates, or that urochordates have a large pharynx with an endostyle? Did you have trouble extending the endostyle to determine the correct answer? 24) D 25) D Version 1
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26) A 27) C 28) A 29) A 30) A 31) B 32) C 33) E 34) A 35) B 36) C 37) E 38) B 39) A 40) A 41) A 42) E 43) C
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Clarify Question ● What is the key concept addressed by the question? ● The fate of the pharyngeal pouches in humans ● What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to predict the effect of lacking pharyngeal pouches. Gather Content ● What do you already know about pharyngeal pouches? What other information is related to the question? ● Pharyngeal pouches are a chordate characteristic. ● In humans, most of the pharyngeal pouches are lost. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer? ● The pharyngeal pouches that are not lost in humans become the Eustachian tubes. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use pharyngeal pouches in a new situation… If you got an incorrect answer, did you remember that pharyngeal pouches are mainly lost, or that one pair of pharyngeal pouches become the Eustachian tubes? 44) E 45) B 46) A
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47) B Clarify Question ● What is the key concept addressed by the question?● The characteristics of Archaeopteryx ● What type of thinking is required?● You are being asked to take what you already know and use, or apply, it to the comparison of features that are present or absent in Archaeopteryx. Gather Content ● What do you already know about the characteristics of Archaeopteryx? What other information is related to the question?● Archaeopteryx had some bird-like characteristics. ● Archaeopteryx had reptilian characteristics. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● Archaeopteryx had feathers and wings. ● Archaeopteryx had a long tail and solid bones. ● Archaeopteryx had teeth. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Answering this question correctly depended on your ability to use the characteristics of Archaeopteryx in a new situation… If you got an incorrect answer, did you remember that Archaeopteryx had had wings and feathers, or that Archaeopteryx had teeth? 48) A
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49) C 50) E 51) D 52) C 53) D 54) E 55) B 56) D 57) C 58) C 59) C 60) B 61) A 62) C 63) E 64) D 65) D 66) D 67) B 68) E 69) D 70) A 71) B 72) C 73) B
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Clarify Question ● What is the key concept addressed by the question?● This question addresses amphibians. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about amphibians?● Amphibians include frogs, salamanders, and wormlike, nearly blind organisms called caecilians. Amphibians have several key characteristics in common: ● 1. Legs. Frogs and most salamanders have four legs and can move about on land quite well. ● 2. Lungs. Most amphibians possess a pair of lungs, although the internal surfaces have much less surface area than do reptilian or mammalian lungs. ● 3. Cutaneous respiration. Frogs, salamanders, and caecilians all supplement the use of lungs by respiring directly through their skin, which is kept moist and provides an extensive surface area for gas exchange. ● 4. Pulmonary veins. After blood is pumped through the lungs, two large veins called pulmonary veins to return the aerated blood to the heart for repumping. In this way, aerated blood is pumped to the tissues at a much higher pressure. ● 5. Partially divided heart. A dividing wall helps prevent aerated blood from the lungs from mixing with nonaerated blood being returned to the heart from the rest of the body. The separation is imperfect, however, because no dividing wall exists in one chamber of the heart, the ventricle. Choose Answer Version 1
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● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Could the animal be a lungfish? No, they don’t have four proper walking legs. ● Could the animal be a reptile? No, they don’t have thin skin with abundant capillaries. Their skin is covered with scales. ● Could the animal be a placental or marsupial mammal? No, they have a fully divided, four-chambered heart. ● Could the animal be an amphibian? Yes. Amphibians respire partly through their skin, and they lack scales, so their skin is thin and there are abundant capillaries underneath for gas exchange. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that amphibians respire partially through their skin? 74) A
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Clarify Question ● What is the key concept addressed by the question?● This question addresses amphibian adaptations to land. ● What type of thinking is required?● This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content ● What do you already know about amphibian adaptations to land?● The successful invasion of land by amphibians posed a number of major challenges: ● Because amphibian ancestors had relatively large bodies, supporting the body’s weight on land as well as enabling movement from place to place was a challenge. Legs evolved to meet this need. ● The delicate structure of fish gills requires the buoyancy of water to support them, and they cannot function in air. Therefore, other methods of obtaining oxygen were required. ● Delivering great amounts of oxygen to the larger muscles needed for movement on land required modifications to the heart and circulatory system. ● Reproduction still had to be carried out in water so that eggs would not dry out. ● The body itself had to be prevented from drying out. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Of all the features listed, only the amniotic egg is not a feature of amphibians. ● Reptiles were the first amniotes, because they were the first to lay their eggs out of the water.
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to take what you already know and apply it to this unfamiliar situation. ● Did you recognize that amphibians lay their eggs in water? ● Did you remember that reptiles first evolved the amniotic egg, not amphibians? 75) C 76) E
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Clarify Question ● What is the key concept addressed by the question?● This question addresses reptile skulls and dinosaur adaptations. ● What type of thinking is required?● This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content ● What do you already know about reptile skulls and dinosaur adaptations?● An important feature of reptile classification is the presence and number of openings behind the eyes. Reptiles’ jaw muscles were anchored to these holes, which allowed them to bite more powerfully. The first group to rise to dominance were the synapsids, whose skulls had one hole behind the openings for the eyes. (Anapsids had no openings – they are represented among extant reptiles only by the turtles.) ● Diapsids have skulls with two pairs of holes on each side of the head, and like amphibians and early reptiles, they were ectotherms. A variety of different diapsids occurred in the Triassic period (213 to 248 mya), but one group, the archosaurs, were of particular evolutionary significance because they gave rise to crocodiles, pterosaurs, dinosaurs, and birds. ● Among the early archosaurs were the largest animals the world had seen, up to that point, and the first land vertebrates to be bipedal—to stand and walk on two feet. By the end of the Triassic period, however, one archosaur group rose to prominence: the dinosaurs. ● Dinosaurs evolved about 220 mya. Unlike previous bipedal diapsids, their legs were positioned directly underneath their bodies. This design placed the weight of the body directly over the legs, which allowed dinosaurs to run with great speed and agility. Subsequently, a number of Version 1
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types of dinosaur evolved to enormous size and reverted to a four-legged posture to support their massive weight. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Based on the two sets of holes in the skull, you can rule out the skeleton being an anapsid or synapsid. It must be a diapsid. ● The bipedal stance with legs directly under the pelvis tells you that this diapsid was not only an archosaur – it was specifically a dinosaur. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. ● Did you recognize that if there are two temporal openings on each side, it must be some kind of diapsid? ● Did you recognize that the vertical placement of legs under the pelvis was a dinosaur adaptation? 77) D 78) D 79) B 80) A 81) A
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Chapter 35 13e MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 1) Plant cells that give rise to two cells, one of which is free to differentiate into various kinds of cells that contribute to the plant body, are called A) endodermal cells. B) primary cells. C) lateral cells. D) parenchyma cells. E) meristematic cells.
2) Cell division in the apical meristems at the tips of a plant that results in increases in height or length is called A) primary growth. B) secondary growth. C) vascular cambium growth. D) mitotic growth. E) herbaceous growth.
3) A growing root comes into contact with a chemical that inhibits the golgi bodies. Which of the following would be a probable effect of this contact? A) The root would begin to growing in an upward direction. B) The root would not be slick enough to move through the soil easily. C) The root would begin to simultaneously grow in multiple directions. D) The root would produce too much mucigel and oxygen uptake would be inhibited. E) The root cap cells would begin to divide rapidly.
4) You propose an experiment where root hairs of a particular plant species are continuously treated with an antibiotic while nutrient levels in the plant tissue are monitored. Based on your knowledge of root hairs, you hypothesize the plant will experience a deficiency in what nutrient?
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A) potassium B) nitrogen C) calcium D) phosphorus E) carbon
5)
An increase in plant diameter results from cell division in which type of meristem? A) Intercalary meristem B) Lateral meristem C) Primary meristem D) Secondary meristem E) Stele meristem
6)
Parenchyma, collenchyma, and sclerenchyma are all types of cells derived from A) procambium tissue. B) ground tissue. C) vascular cambium tissue. D) cork cambium tissue. E) epidermal tissue.
7)
If thewer gene were expressed in every root epidermal cell, the plant would A) greatly increase its absorptive capacity. B) strengthen its attachment to the soil. C) increase in the diameter of its roots. D) greatly reduce its water and nutrient uptake. E) greatly reduce its ability to exchange gases at the epidermal surface.
8)
A stem that cannot increase in diameter is lacking what type of tissue?
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A) xylem B) ground meristem C) procambium D) protoderm E) vascular cambium
9)
The slender stalk that connects the flattened leaf blade to the stem in most dicots is the A) meristem. B) petiole. C) stele. D) receptacle. E) vein.
10) You are given a sample of plant tissue and asked to identify the type of tissue and its location in the plant. Using your microscope, you notice two distinct layers of cells. One layer contains cells that are tightly compacted together while the other layer has loosely arranged cells. The cells in both layers contain many chloroplasts. Based on this information, you determine the tissue is A) mesophyll tissuefrom a leaf. B) ground tissue from a stem. C) vascular tissue from a leaf. D) mesophyll tissue from a stem. E) vascular tissue from a root.
11) You are asked to determine if a tissue sample taken from a plant stem comes from a monocot or eudicot. How will you accomplish this?
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A) Look at the ground tissue to see if it is arranged in concentric rings or in parallel bundles. B) Examine the vascular cambium and determine if it is divided into segments or is continuous throughout the stem. C) Determine if the xylem and phloem are located in separate vascular bundles or are bundled together. D) Examine the epidermis and determine the depth of the cuticle layer. E) Locate the vascular bundles and analyze their pattern.
12)
Xylem tissue may contain each of these cell types, except which? A) vessel members B) tracheids C) sieve cells D) fibers E) rays
13)
Which of the following cell types does not move materials through the body of the plant? A) sclerenchyma B) xylem vessel members C) sieve tube members D) tracheids E) sieve cells
14) by
A plant that has the mutant form of the WEREWOLF gene ( wer) would be identifiable
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A) the excessive number of vascular bundles in stem. B) the lack of fibers in the outer portions of the stem. C) the abundance of microscopic hairs on the root. D) the extra thick layer of mesophyll cells in the leaf. E) the lack of microscopic hairs along the epidermis of the root.
15) Primary growth at the apical meristems can produce cells that differentiate into each of these cell types, except which? A) leaves B) ground tissue C) procambium D) cork cambium E) epidermis
16)
Primary growth in plants originates in A) apical meristems. B) lateral meristems. C) vascular cambium. D) cork cambium. E) tracheids.
17)
Which of the following is not true about meristems?
A) They can be apical or lateral. B) Meristematic cells divide into two cells, one of which remains a meristem cell and another that becomes a plant body cell. C) Apical meristems give rise to three types of embryonic tissues. D) Meristematic cells are found only in eudicots and not in monocots. E) They are responsible for primary and secondary growth.
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18) You have been assigned the task of identifying the cells in a plant tissue sample. Using your microscope you determine the cells are living and their cell walls vary in thickness. Upon further observation you note that the cells are arranged in strands just below the epidermal surface. What cell type do you determine the cells to be? A) Collenchyma B) Parenchyma C) Sclerenchyma D) Sieve elements E) Tracheids
19)
All of the following describe characteristics of sclerenchyma cells, except which? A) Their function is primarily to transport oxygen and carbon dioxide throughout the leaf. B) They have thick, tough secondary walls. C) Their secondary walls may be impregnated with lignin. D) They form fibers and sclereids. E) They lack living protoplasts when mature.
20)
Which of the following cell types conducts water most rapidly through a plant? A) parenchyma cells B) sclerenchyma cells C) sieve tubes D) vessel members E) phloem
21) You have been given a plant sample and asked to identify a specific tissue. Upon investigation, you find the cells are all long in length and some of them have small pores. They all contain fluid. You test the fluid using various biochemical tests and discover the fluid contains an abundance of disaccharides. What type of tissue are you looking at?
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A) xylem B) phloem C) root hair cells D) sclerenchyma E) meristematic
22)
In plants with only primary growth, the epidermis is not A) one cell thick. B) the outer protective coating of the plant. C) produced by the protoderm. D) covered by a waxy layer that constitutes the cuticle. E) covered with bark.
23)
Horizontal rows of parenchymal cells that transport materials horizontally are called? A) rays B) tracheids C) vessel elements D) fibers E) sieve tubes
24)
Root hairs grow actively in which area of the developing roots? A) root cap B) zone of maturation C) zone of elongation D) zone of cell division E) endodermis
25)
Which of the following statements correctly describes the vascular cambium?
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A) It develops between the primary xylem and the primary phloem in dicots. B) It occurs only in monocot stems. C) It is important in the elongation of roots. D) It is formed by the ground meristem. E) It is responsible for all cell types that result from primary growth.
26) In certain plants, some of the roots may be modified to carry out unusual functions. Which of these is not an example of one of these special functions? A) help absorb oxygen B) store food or water C) carry out photosynthesis D) parasitize other plants E) discourage herbivores
27)
Compound leaves A) have two or more petioles per blade. B) have a blade divided into leaflets. C) are toothed at the edges. D) are alternately arranged. E) have palmate venation.
28)
Which of the following is not a modified stem? A) rhizome B) tendril C) tuber D) corm E) spine
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29)
Axillary buds A) add length to a plant. B) develop into roots when water is scarce. C) form flowers or branches. D) increase the diameter of a stem. E) form lateral meristems.
30)
The most distinctive characteristic of leaf mesophyll cells is that they are filled with A) centralvacuoles. B) many chloroplasts. C) oxygen bubbles. D) veins. E) stomata.
31) Various modifications in leaves can make plants better adapted to their habitats. Which of the following is not an evolutionary modification of leaves? A) floral leaves B) fruit-bearing leaves C) spines D) reproductive leaves E) insectivorous leaves
32) A birdhouse is nailed into a tree 6 feet up from the ground. If the tree grows about 2 feet taller each year, how far from the ground will the birdhouse be 25 years later?
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A) 50 feet B) 56 feet C) 26 feet D) 6 feet E) 4 feet
33)
Which statement about secondary growth in plants is not correct?
A) Secondary growth in plants is a result of lateral meristems. Trees and shrubs have active lateral meristems. B) Secondary growth in plants increases the girth (diameter) of woody plants. C) Secondary growth in woody plants results from two cylinders of actively dividing cells, the cork cambium and vascular cambium. D) The cork cambium produces secondary phloem while the vascular cambium produces secondary xylem. E) Only some plants have secondary growth.
34) You are doing research on rodent populations in a cornfield at night and are hearing popping noises. Your research assistant is getting scared. Having taken biology, you can explain to your assistant that the popping sound is due to A) the apical meristem cells in the corn stalks elongating. B) the developing of the kernels of corn on the ears of the corn stalks. C) the expansion of the lateral meristems increasing the girth of the corn stalk. D) the growth of the intercalary meristems inside the corn stalk. E) the development of the tassels on top of the corn stalk.
35) If you examined a cross-section of a woody stem under the microscope and located the vascular cambium, the tissues on the inside of the vascular cambium ring (toward the center of the stem) would be
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A) xylem (primary and secondary). B) xylem (only primary). C) phloem (primary and secondary). D) phloem (only secondary). E) phelloderm.
36)
Of the following structures, which one is not a specialized cell of the epidermis? A) guard cells B) trichomes C) sclereids D) root hairs E) oil glands
37)
Which statement concerning root hairs is not correct? A) Root hairs are tubular extensions of individual epidermal cells. B) A root hair is isolated from its epidermal cell with a cross wall. C) Root hairs generally live only a few days before being sloughed off. D) Root hairs increase the absorption of water and minerals. E) Root hairs are located in the zone of maturation of a root.
38) You come across a recipe for rhubarb pie. Never having heard of rhubarb, you do a little research. You find out that the part of a rhubarb plant that people eat is the petiole of a large leaf. You purchase some rhubarb for your pie and notice that it contains many long stringy fibers. Based on your knowledge of plant tissues, you know that the stringy fibers are A) parenchyma tissue. B) phloem tissue. C) sclerenchyma tissue. D) collenchyma tissue. E) xylem tissue.
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39) A friend who is not a biologist tells you that she grows irises from iris roots. You explain to her that the "root" she is planting is not a root, but instead is called a rhizome. "Why?" she asked. You explain: A) "A root grows vertically, not horizontally." B) "A rhizome has nodes and internodes and is really a modified stem that can exist underground." C) "A root stores nutrients, but rhizomes are underground stems that do not store nutrients." D) "A rhizome, although a modified stem, acts as a root does. In other words, a rhizome is a stem-root combination." E) "A rhizome is a modified root that is able to grow leaves."
40) the
The name of the meristem that ultimately gives rise to secondary xylem and phloem is
A) vascular cambium. B) cork cambium. C) intercalary meristems. D) ground meristem. E) primary meristem.
41)
The pattern of leaf arrangement on a stem is called A) protodermis. B) phyllotaxy. C) nodular termini. D) meristematic spacing. E) axillary arrangement.
42)
Primary xylem and phloem are produced by the
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A) procambium. B) protoderm. C) leaf primordial. D) ground meristem. E) proembryo.
43) The waterproof cuticle covering the epidermis of land plants helps prevent dehydration, much like the skin of some land animals. As a consequence of having a cuticle, what other evolutionary adaptation was important for most land plants? A) the endodermis in the root B) root hairs on the root epidermis C) collenchyma fibers just beneath the surface of the epidermis D) stomata in the leaves E) trichomes on leaf surfaces
44)
Which of these is not a function of the root cap? A) gravity perception B) rapid cell division C) protection of the root tip D) pushing away soil particles as the root grows E) releasing a slimy lubricant fluid
45) In an experiment, some herbaceous, nonwoody plants were exposed to frequent windy conditions or mechanical shaking for several hours per day. The flexibility of these plants was due to the_________blank cells.
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A) parenchyma B) aerenchyma C) periderm D) collenchyma E) sclerenchyma
46) Linen is woven from strands of sclerenchyma_________blank that occur in the phloem of flax ( Linum spp.). A) tracheid B) sieve C) sclereid D) collenchyma E) fiber
47) the
A major distinguishing feature between monocot and eudicot stems is the organization of
A) epidermis. B) conducting system. C) vascular tissue. D) secondary tissues. E) ground tissues.
48)
How could you distinguish between a root hair versus a very small root? A) Root hairs are white, while roots are brown. B) Root hairs are extensions of single cells, while roots are multicellular. C) Root hairs only absorb water, not nutrients like roots. D) Root hairs do not have a cuticle. E) The epidermis of a root hair is thinner than the epidermis of a root.
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49) What type of cells are joined end-to-end, conduct water and are connected to each other with strips of wall material? A) sieve cells B) tracheids C) sieve tube members D) vessel members E) companion cells
50) In the vascular bundles of most dicot stems, primary phloem differentiates toward the_________blank of the stem, while primary xylem differentiates toward the_________blank of the stem. A) middle; outside B) cork cambium; vascular cambium C) outside; middle D) shoot tip; roots E) middle; middle
51)
Damage to the ground meristem of a plant would result in A) the inability to move water but not sugar through the plant. B) decreased sugar production. C) an increase of gas exchange at the surface of the leaf. D) dehydration of the plant. E) inability to move sugar but not water through the plant.
52)
Secondary phloem
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A) includes live companion cells and dead sieve cells. B) encompasses more stem volume than secondary xylem. C) primarily stores carbohydrates. D) is part of the inner bark. E) is produced by the cork cambium.
53)
Which of these can found in oak wood but not in pine wood? A) secondary xylem B) secondary phloem C) vessel members D) tracheids E) ray cells
54)
Which plant cells are the most common and the least specialized? A) epidermis B) collenchyma C) sclerenchyma D) parenchyma E) meristem
55) Your lab instructor hands you a root slide and asks you to show her a cell with condensed chromosomes arranged in a straight line. In which section of the root would you begin your search? A) It doesn't matter, all zones have the same level of mitotic activity. B) zone of elongation C) zone of maturation D) zone of cell division E) root cap
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56) Maple syrup is made by concentrating the sucrose-rich sap of a maple tree in the spring when the days are warm and the nights are below freezing. To get the sap, metal taps are hammered into the trunk of a maple tree. Conditions must be right so that the sap rises from the root in the xylem during the day (flowing out the tap as it does) and flows back to the roots during the night. How deep should the tap be driven into the trunk? A) The tap should be placed a bit past the vascular cambium B) Just past the bark C) Until the tip is in the phelloderm just past the cork cambium D) So that it is near, but not through, the vascular cambium E) All the way into the heartwood.
57) During a woodworking class, Kim’s instructor lectures on the grain of the wood. The instructor explains that when you look at the end of a board cut perpendicular across the tree trunk, the curved lines you see (called end grain) are actually the growth rings of the tree. Kim has also taken a biology class, and realizes that these lines composed of what types of cells? A) Vessels B) Xylem rays C) Cork cambium D) Sieve plates E) Phelloderm
58) Many monocots use a modified photosynthetic pathway, C4 photosynthesis, that maximizes the amount of CO2 relative to O2 to reduce energy loss through photorespiration. Which of the following is an anatomical feature that corresponds with C4 photosynthesis? A) Stomata closed during hot days B) Thin epidermis lacking a cuticle C) Well-differentiated palisade and spongy mesophyll D) Prominent bracts E) Insectivorous leaves to meet resulting nutritional deficiencies
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59) The red mangrove, Rhizophora mangle, grows along the Gulf coast of the southeastern United States. These trees are sometimes called “walking trees”, because throughout their lives they spread out across the water and the branches periodically grow down into the salt water to provide support for the spreading canopy. These thin leglike roots provide habitat for a wide variety of sea life and trap sediments that can form islands. What do we call these specialized roots? A) Prop roots B) Pneumatophores C) Tubers D) Buttress roots E) Aerial roots
SECTION BREAK. Answer all the part questions. 60) Choose the letter of the best match from the following: A. protoderm B. vascular cambium C. apical meristem D. procambium E. ground meristem
60.1)
Ultimate source of all cells that contribute to growth in length of stem or root.
60.2)
Lateral meristem that contributes to the increase in thickness of a stem or root.
60.3)
Source of cells that differentiate into primary vascular tissues.
60.4) The three primary meristems are the_________blank, which forms the epidermis; the procambium, which produces primary vascular tissues (primary xylem and primary phloem); and the ground meristem, which differentiates further into ground tissue.
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60.5)
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Answer Key Test name: Chap 35_13e_Raven 1) E 2) A 3) B
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Clarify Question ● What is the key concept addressed by the question?● The role of the Golgi bodies to a growing root in a plant. ● What type of thinking is required?● You must apply what you know about the function of the Golgi to deduce the effects of their inhibition in a plant. ● What key words does the question contain and what do they mean?● Golgi, which is an organelle that processes macromolecules. Gather Content ● What do you already know about the function of golgi bodies in plant root cells? How does it relate to the question?● Golgi bodies produce mucigel. ● Mucigel moves through the plant cell walls. ● The passage of roots through soil is eased by mucigel. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Mucigel does not directly affect the cell division rate or growth direction of the root. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Recall that Golgi in general are in involved in macromolecule processing in cells. ● In root cells, the Golgi produce mucigel, which is a slimy substance that moves through the cell wall to the outside of the cell. Version 1
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● Mucigel allows the root tip to slide through the soil as it grows. ● If the Golgi bodies are inhibited, mucigel production will be inhibited. ● If mucigel is not produced, the root tip will not move through the soil smoothly as it grows. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● This question asked you to utilize the importance of the Golgi. Answering this question correctly depended on your ability to use the function of the Golgi in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that Golgi produce mucigel, or that mucigel allows root tips to move through the soil more readily? Did you have trouble extending the function of the Golgi to determine the correct answer? 4) B
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Clarify Question ● What is the key concept addressed by the question?● The question addresses the effects of the removal of symbiotic bacteria from a plant. ● What type of thinking is required?● Apply, because you must take what you know about the effects of antibiotics and apply that to symbiotic relationships that occur between plants and microorganisms. ● What key words does the question contain and what do they mean?● Root hairs, which is an extension from a root that absorbs minerals and water. ● Antibiotic, which is a chemical that kills bacteria. ● Nutrient, which is an element of food that helps a living thing to survive. Gather Content ● What do you already know about the funtion of symbiotic bacteria in plants? How does it relate to the question?● Certain antibiotics kill certain bacteria. ● Plants have symbiotic bacteria that fix nitrogen from the atmosphere. ● Root hairs provide a pathway for symbiotic bacteria into the plant. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Bacteria aid in the absorption and storage of nitrogen, particularly for some groups of plants (the legume family Fabaceae), acting as symbionts which form nodules on the roots. ● Other nutrients do not require bacterial intervention.
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Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The indicator that the question was focused on nitrogen is the use of the antibiotic. ● Since antibiotics kill certain bacteria, the use of the antibiotic would remove the nitrogen-fixing symbionts from the plant. ● Without the nitrogen-fixing bacteria, the plant would be deficient in nitrogen. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● This question asked you to understand the relationship between bacteria and plants. Answering this question correctly depended on your ability to use the role of bacteria in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that bacteria fix nitrogen into a usable form for some plants, or that antibiotics kill bacteria? Did you have trouble extending the role of bacteria to determine the correct answer? 5) B 6) B 7) D
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the role of the wer gene. ● What type of thinking is required?● You must apply what you know about the wer gene to deduce the effects on the structure of a plant. ● What key words does the question contain and what do they mean?● wer, which is a gene that limits root hair growth. ● Root epidermal cell, which occur at the periphery of roots. Gather Content ● What do you already know about the function of the WER gene in root epidermal cells of plants? How does it relate to the question?● The wer gene limits the growth of root hairs. ● The wer gene mutation causes an excess of root hairs. ● wer is a reference to werewolf. ● Root hairs increase the surface area for absorption of materials into the root. Consider Possibilities ● What other information is related to the question? Which information is most useful?● The wer gene does not affect root diameter. ● The wer gene does not promote attachment of the root to the soil. ● If wer is expressed, absorption of materials would not increase, because fewer root hairs would be present Choose Answer Version 1
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● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● To answer this question, you need to associate the expression of the wer gene with decreased root hairs. ● Decreased water and nutrient uptake occur with decreased root hairs. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● This question asked you to infer the consequences of a mutation in the wer gene. Answering this question correctly depended on your ability to use the function of wer in a new situation… If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that wer limits the growth of root hairs or that if mutated, this gene causes an excess of root hairs to grow? Did you have trouble extending the function of wer to determine the correct answer? 8) E Monocot stems lack a vascular cambium (and cork cambium) and therefore do not increase in girth (diameter). 9) B 10) A
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Clarify Question ● What is the key concept addressed by the question?● Plant tissue can be specifically identified by using a microscope and examining the shape, characteristics, and placement of cells. ● What type of thinking is required?● Apply, because you must remember what you know about plant tissues, and then apply it to an unknown sample ● What key words does the question contain and what do they mean?● Chloroplast, which is the organelle in which photosynthesis occurs. ● Loosely arranged cells, which can have a spongy appearance and in plants can refer to a specific mesophyll. ● Compacted cells, which can refer to a specific type of mesophyll. Gather Content ● What do you already know about the shape, characteristics, and arrangement of plant cells? How does it relate to the question?● Mesophyll tissue has spongy and a compact (palisade) layers in eudicots. ● Chloroplasts are found throughout the mesophyll. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Vascular tissue would have bundles of xylem and phloem, and would not have chloroplasts. ● Ground tissue would have parenchyma, sclerenchyma, and collenchyma Choose Answer Version 1
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● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● To answer this question, you need to recall the cellular characteristics of each of the major tissue types of a plant. ● Focusing on the presence of chloroplasts, as well as the spongy and compacted cell layers, leads to only one conclusion ● The presence of the spongy and compact layers with chloroplasts is sufficient to determine this is mesophyll. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● This question asked you to identify cells in plant tissue. Answering this question correctly depended on your ability to use your knowledge of cells and tissues in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that mesophyll has spongy and compact layers, or that chloroplasts are plentiful in mesophyll? Did you have trouble extending your knowledge of plant tissues to determine the correct answer? 11) E Both monocots and eudicots have vascular bundles that contain both xylem and phloem. Monocots have these vascular bundles arranged randomly throughout the stem while eudicots have these bundles located in a circular pattern toward the outside of the stem. 12) C Sieve cells are characteristic of phloem. 13) A Version 1
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Sclerenchyma cells function in adding strength to plant tissues. 14) C The WEREWOLF gene ( wer) inhibits root hair development in root epidermal cells. In contrast, the mutant form of the gene ( wer) facilitates the development of root hairs. 15) D Cork cambium as well as vascular cambium are tissues generated from a lateral meristem and are therefore referred to as secondary plant growth. 16) A Apical meristems produce the primary plant body while the lateral meristems produce the secondary plant body. 17) D Meristems are areas of a plant that produce growth. Apical meristems add length and produce the primary plant tissues while lateral meristems add girth and produce the secondary plant tissues. 18) A
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Clarify Question ● What is the key concept addressed by the question?● Plant cells can be identified by examining its microscopic characteristics. ● What type of thinking is required?● Apply, because you must remember what you know about plant cells, and then apply it to an unknown sample. ● What key words does the question contain and what do they mean?● Strands, which refers to a long growth pattern of cells in tissue. ● Epidermal surface, which refers to the tissue that covers the plant body. Gather Content ● What do you already know about the characteristics of plant cells as viewed through a microscope? How does it relate to the question?● Collenchyma cells have walls of varying thicknesses. ● Collenchyma cells often form strands. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Parenchyma have thin walls and are initially spherical. ● Sclerenchyma have tough, thick walls. ● Tracheids are dead, hollow cells. ● Sieve elements are narrow and stacked Choose Answer ● Given what you now know, what information and/or problem solving Version 1
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approach is most likely to produce the correct answer?● When you are presented with an identification question, you must look for identifying characteristics that are possessed by only one of the possible cell types. Collenchyma cells can be identified by their variable cell wall thickness, and by their tendency to form strands. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● This question asked you to recognize plant tissues. Answering this question correctly depended on your ability to use the characteristics of plant tissues in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that collenchyma cells tend to form strands, or that collenchyma cells have variable cell wall thickness? Did you have trouble extending plant tissue characteristics to determine the correct answer? 19) A Unlike other cells derived from ground tissue, sclerenchyma die at maturity. Their secondary cell wall is lignified which makes the cell very rigid and this adds strength to the plant tissue. 20) D
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Xylem, which transports water through the body of a plant, is composed of tracheids and vessel members. Both of these cell types are dead at maturity. Water moves between tracheids, which sit next to one another, through pits. The vessel member cells are joined end to end with the space between cells almost completely open or punctuated with strips of cell wall material. This allows water to travel faster through the vessel members. 21) B
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Clarify Question ● What is the key concept addressed by the question?● Plant tissues can be identified by looking at their cellular composition. ● What type of thinking is required?● You must apply what you know about plant tissues to identify an unknown sample. ● What key words does the question contain and what do they mean?● Biochemical tests, which include tests that can be used to detect macromolecules such as carbohydrates, proteins, lipids, etc. ● Monosaccharides, which are carbohydrates that are composed of one sugar building block. Gather Content ● What do you already know about the cellular composition of different types of plant cells? How does it relate to the question?● Glucose, a product of photosynthesis, is a monosaccharide. ● Phloem transports nutrients, including monosaccharides. ● Phloem cells are long and have small pores. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Xylem transports water. ● Root hair cells are tubular and occur just behind the roots. ● Sclerenchyma cells have tough, thick walls. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● The Version 1
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abundance of monosaccharides is an important clue to the identification of this phloem tissue. Also, the physical characteristics noted in the question are only found in phloem. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where ● Apply level:● This question asked you to deduce an unknown tissue type. Answering this question correctly depended on your ability to use known characteristics of tissue in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that phloem carries monosaccharides, or that phloem cells tend to be long with small pores? Did you have trouble extending the characteristics of the tissues to determine the correct answer? 22) E Only plants with lateral meristems exhibit secondary growth. Bark results from secondary growth. 23) A Rays are parenchyma cells produced in horizontal rows by special ray initials (meristematic cells) of the vascular cambium. They function in lateral conduction and food storage. Remember that vascular cambium is part of the secondary plant body and it produces woody tissues. 24) B Root hairs are common only in the zone of maturation. 25) A
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Some dicots have both primary growth (initiated by apical meristems) and secondary growth (initiated by lateral meristems). There are two types of lateral meristems, cork cambium and vascular cambium. The vascular cambium initially develops between the primary phloem and primary xylem. As it produces new vascular tissue, it becomes surrounded by secondary phloem and secondary xylem. 26) E Evolution has resulted in many types of modified roots. 27) B Unlike simple leaves, compound leaves are divided into smaller sections. 28) E Spines form from modified leaves not stems. 29) C Apical buds that form at the tips of stems add length to the plant. Axillary buds that form primary plant tissues are located in the space between a leaf and a stem and form either branches or flowers. 30) B Since leaves are the main photosynthetic organ of a plant, the mesophyll cells within a leaf are filled with chloroplasts. The chloroplasts function to capture sunlight energy and convert it into chemical energy. 31) B 32) D
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Clarify Question ● What is the key concept addressed by the question?● The mechanism of growth in a plant. ● What type of thinking is required?● You must apply what you know about plant growth to a new situation. ● What key words does the question contain and what do they mean?● Tree, which is a perennial plant with an elongated stem and branches. ● 25 years later, which means the tree will have changed in height. ● 6 feet up from the ground, which is the original location on the stem/trunk for the birdhouse. Gather Content ● What do you already know about a tree grows? How does it relate to the question?● Apical meristems cause an increase in plant height. ● Apical meristems occur at the top of a plant. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Trees to not increase in height from the bottom up; rather they grow at their upper margins. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● To answer this question, you need to understand that increases in the height of plant occur from the top. Any structures lower than the apical meristem do not change in elevation, even as the tree grows. As long as the bird house is Version 1
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not placed at the top of a tree, it will not change in elevation, even as the tree grows. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● This question asked you to extrapolate the position of a birdhouse in a growing tree. Answering this question correctly depended on your ability to use the mechanism of growth in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that the apical meristem is where increases in height occur, or that the apical meristem occurs at the top of a tree? Did you have trouble extending the mechanism of plant growth to determine the correct answer? 33) D Secondary growth, which increases the diameter of a plant, occurs in some eudicots. This increase in diameter or girth, is due to the presence of lateral meristems. There are two types of lateral meristems, the cork cambium and the vascular cambium. The cork cambium contributes to the outer bark while the vascular cambium produces both secondary xylem and secondary phloem. 34) D
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In addition to apical meristems, some plants have intercalary meristems. Both apical and intercalary meristems add length to the plant. Apical meristems are located at the tip of the stem while intercalary meristems are located within the internodes of the plant. Intercalary meristems can produce growth so quicky that it can cause a popping sound. 35) A
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Clarify Question ● What is the key concept addressed by the question?● A cross section of a woody stem is made up of different tissues. ● What type of thinking is required?● You must apply what you know about individual tissues of the woody to identify those in the central region of the stem. ● What key words does the question contain and what do they mean?● Cross section, which is a section of tissue that is cut perpendicular to the long axis of the organism. ● Woody stem, which is the trunk of the tree. ● Vascular cambium, which is the tissue between the xylem and the phloem. Gather Content ● What do you already know about the different tissues in a woody stem? How does it relate to the question?● The vascular cambium lies just inside the bark of a woody stem. ● Xylem is added to the inside of the vascular cambium. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Phloem is added to the outside of the vascular cambium. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● To answer this Version 1
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question, you need to focus on the reference to the tissue inside the vascular cambium ring. If you connect that to the location of xylem on the inside of that ring, you have the correct answer. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● This question asked you to asses a section of tissue. Answering this question correctly depended on your ability to use the characteristics of the tissue in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that xylem is on the inside of the vascular cambium, or that phloem is on the outside of the vascular cambium? Did you have trouble extending the characteristics of the plant tissues to determine the correct answer? 36) C Sclereids are part of the ground tissues of plants. Ground tissue cells function in storage, photosynthesis, and secretion. Sclereids are a type of sclerenchyma cell which may have an irregular shape. Their function is to strengthen the tissues where they are found. 37) B A root hair is an extension of an epidermal cell and is not separated from the cell by a cross-wall. 38) D
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Clarify Question ● What is the key concept addressed by the question?● Plant cell types can be differentiated by individual characteristics. ● What type of thinking is required?● You must apply what you know about individual cell types to identify an unknown cell type in a sample. ● What key words does the question contain and what do they mean?● Petiole, which is a stalk on the leaf that attaches it to the stem of a plant. Gather Content ● What do you already know about the characteristics of different plant cell types? How does it relate to the question?● Collenchyma cells have walls of varying thicknesses. ● Collenchyma cells often form strands. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Parenchyma may have thin cell walls, but it is not stringy. ● Phloem has long cells with small pores, but it is not stringy. ● Xylem contains vessels, but is not stringy. ● Sclerenchyma cells are typically dead at maturity, and is not stringy. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● If you connect the ideas that the unknown cells are from the petiole of the leaf, and that they are stringy, you can only conclude this is collenchyma. Version 1
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Collenchyma is known for its fibrous, stringy nature. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● This question asked you to identify an unknown plant tissue. Answering this question correctly depended on your ability to use your knowledge of the characteristics of plant tissue in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that collenchyma is known for its fibrous, stringy nature., or that other tissues are not of this nature? Did you have trouble extending your knowledge of the characteristics of plant tissue to determine the correct answer? 39) B A rhizome is a type of modified stem that functions in plant propagation. These tend to run horizontally underground. Because a rhizome is a stem, it contains nodes and internodes. The nodes contain leaves and axillary buds. Roots do not have nodes/internodes/leaves or axillary buds. 40) A Vascular cambium is one of two types of lateral meristems in woody tissues. The cork cambium contributes to the outer bark while the vascular cambium, as its name suggests, generates vascular tissues. 41) B Phyllotaxy refers specifically to the arrangement of leaves on a stem.
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42) A The apical meristem produces three tissue systems. The protoderm goes on to produce the epidermis of the plant. The ground meristem produces the ground tissues. The procambium gives rise to the primary vascular tissues (primary xylem and primary phloem). 43) D The cuticle is a waxy coating of a leaf. Although the cuticle is an effective way to reduce water loss, it can interfere with the exchange of gases (carbon dioxide into the leaf, oxygen out of the leaf). So stomata, small pores in the leaf epidermis were another necessary evolutionary adaptation for land plants. 44) B The area of the root responsible for rapid cell division is the Zone of cell division. 45) D
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Clarify Question ● What is the key concept addressed by the question?● Different types of plant cell types have different functions within a plant. ● What type of thinking is required?● You must apply what you know about the functions of individual cell types to recognize an unknown cell type in a sample. ● What key words does the question contain and what do they mean?● Nonwoody plant, which refers to a plant that is herbaceous, with a green rather than a wood-based stem. ● Flexibility, which means there is a great range of movement. Gather Content ● What do you already know about the composition and function of various plant cells types? How does it relate to the question?● Collenchyma cells provide flexibility to a plant. ● Collenchyma cells often form strands. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Parenchyma may have thin cell walls. ● Sclerenchyma cells are typically dead at maturity, and are not flexible. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● If you connect the ideas that the unknown cells are from the stem of the plant and that they are flexible and strong, you can only conclude this is collenchyma. Version 1
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Collenchyma is known for its flexible nature. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● This question asked you to identify a plant tissue. Answering this question correctly depended on your ability to use the known characteristics of plant tissues in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that collenchyma is known for its flexibility, or that other tissues are not nearly as flexible? Did you have trouble the known characteristics of plant tissues to determine the correct answer? 46) E 47) C Monocots and eudicots vary in the arrangement of the vascular tissues within the stem. In monocots, the vascular bundles are scattered through the stem. In eudicots, the vascular bundles are arranged in a ring around the periphery of the stem. 48) B Root hairs are simply extensions of individual root epidermal cells. So root hairs are much smaller than roots. Since root hairs are small and can access tiny areas within the soil, root hairs function to keep the plant in intimate contact with the soil. The majority of water and nutrient absorption takes place via the root hairs. Root hairs are confined to the zone of maturation on a root.
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49) D Sieve cells, companion cells and sieve tube members are all part of the phloem, tissue that conducts food (sugar) materials throughout the plant. Tracheids and vessel members conduct water. Vessel members are cells that are joined end to end. Where two cells meet, they are connected by strips of cell wall material (called perforation plates). The gaps between these strips allows water to travel very efficiently through the plant. 50) C In eudicots, the primary vascular tissues are arranged in a ring toward the periphery of the stem. The xylem develops on the inside of this ring while the phloem develops toward the outside of the ring. 51) B
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Clarify Question ● What is the key concept addressed by the question?● The ground meristem plays an important role in the life of a plant. ● What type of thinking is required?● You must apply what you know about the functions of the ground meristem to identify the effects of damage to that tissue. ● What key words does the question contain and what do they mean?● Ground meristem, which has functions that include giving rise to photosynthetic tissues. Gather Content ● What do you already know about the function of ground meristem in plants? How does it relate to the question?● Ground meristem functions in photosynthesis, storage, secretion, support, and protection. ● Photosynthesis produces sugar. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Ground meristem is not involved in transport of water and nutrients. ● Ground meristem is not involved in gas exchange. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● You need to connect the functions of ground meristem to this example by imagining what would happen to the plant if the ground meristem is compromised. Version 1
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Since the ground meristem, gives rise to the photosynthetic tissues, if the ground meristem is compromised, there would be fewer photosynthetic tissues. With lower rates of photosynthesis, there would be less sugar produced. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● This question asked you to extrapolate the effects of tissue damage. Answering this question correctly depended on your ability to use the function of specific tissues in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that ground meristem gives rise to tissues that photosynthesize? Did you have trouble extending the function of specific tissues to determine the correct answer? 52) D Woody plants have a vascular cambium that develops just beneath the bark. The vascular cambium produces secondary vascular tissues. Secondary xylem is produced towards the inside of the tree while secondary phloem is produced towards the outside of the tree and is part of the inner bark. 53) C The xylem of pine trees and other gymnosperms contains only tracheids. In comparison, the xylem of angiosperms, which includes flowering trees like oaks, has both tracheids and vessel members.
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54) D Ground tissue contains three primary cell types. Collenchyma cells remain alive for many years, have cell walls of various thicknesses and provide flexibility and strength for the plant. Sclerenchyma cells are dead at maturity and have thick lignified secondary cell walls that function to strengthen plant tissues. Parenchyma cells are the least specialized, alive at maturity and function in storage, photosynthesis and secretion. 55) D
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Clarify Question ● What is the key concept addressed by the question?● The cellular activities of the root zones. ● What type of thinking is required?● You must apply what you know about the nature of a root to identify the location of the process at hand. ● What key words does the question contain and what do they mean?● Root tip, which is an area of active growth and cell division. Gather Content ● What do you already know about the appearance of root cells in the different zones? How does it relate to the question?● The zone of cell division in a plant root is a site of active mitosis. ● Students often use slides from this zone to examine all of the mitotic phases. ● Chromosomes are visible using a light microscope during mitosis. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Zone of maturation contains cells that differentiate. ● Zone of elongation contains cells that elongate via the merging of small vacuoles. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● You need to connect the zone of cell division to the highest amount of mitosis. Version 1
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Abundant mitosis would provide the best opportunity to view condensed chromosomes that are in a straight line, as they would be in mitotic metaphase. You can rule out options that include functions not covered by the zone of cell division. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● This question asked you to differentiate the roles of the zones in a root tip. Answering this question correctly depended on your ability to use your knowledge of each zone in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that the zone of cell division has active mitosis, or that chromosomes condense and are visible during mitosis? Did you have trouble extending the functions of each zone to determine the correct answer? 56) A
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Clarify Question What is the key concept addressed by the question? ● What tissue transports xylem sap? What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to determine where to tap for maple sap. Gather Content What do you already know about eudicot stems? What other information is related to the question? ● Eudicot stems undergo secondary growth. ● Vascular cambium produces xylem on the inside of the shoot and phloem on the outside. ● Cork cambium produces phelloderm on the inside of the cambium and cork on the outside. ● The xylem closest to the vascular cambium, called sapwood, conducts water and dissolved substances. ● The xylem at the center of the shoot, heartwood, does not conduct water anymore. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● To harvest the xylem sap for maple sugar, you want to place the tap into the sapwood. This is located just past the vascular cambium. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use knowledge of eudicot structure in a new situation… If you got an incorrect answer, did you notice that maple sugar is made from xylem Version 1
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sap, or that xylem sap is transported by sapwood located on the interior side of the vascular cambium? Did you have trouble extending eudicot structure to determine the correct answer? 57) A
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Clarify Question What is the key concept addressed by the question? ● Can you recognize the structures of a woody trunk? What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to recognize the cellular structure of wood grain. Gather Content What do you already know about growth rings? What other information is related to the question? ● The growth rings in trees are the rings of xylem laid down by the vascular cambium. ● The xylem cells run parallel to the shoot (trunk) so that they can transport water up the tree. ● If you cut across the trunk (like when you cut down a tree) you can see the rings formed by the cross section of the xylem cells, which are called vessels or tracheids. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● The end grain of a board the pattern of openings in the ends of vessels running up the trunk. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use knowledge of eudicot shoot structure in a new situation… If you got an incorrect answer, did you remember that wood is composed of xylem, or that xylem cells run up the length of the trunk? Did you have trouble extending eudicot structure to determine the correct answer? Version 1
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58) A
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Clarify Question What is the key concept addressed by the question? ● What is the advantage of C4 photosynthesis? What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to identify how plants avoid dehydration… Gather Content What do you already know about photosynthesis and photorespiration? What other information is related to the question? ● The reactants in photosynthesis are carbon dioxide (which plants take in through stomata) and water (which plants take in through roots). ● When stomata are open, oxygen (produced by photosynthesis) and water will exit the plant. ● In hot, dry environments, plants can close their stomata to avoid dehydration, but doing so causes the amount of CO2 relative to O2 to decrease, resulting in photorespiration. ● Photorespiration is an extra energy expense for the plant. ● By using a modified photosynthetic pathway, C4 plants can avoid photorespiration, and thus the energy loss, when they close their stomata to conserve water. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● The advantage of the C4 pathway is the ability to conserve water in a hot, dry environment by closing stomata and still avoiding photorespiration. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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● Answering this question correctly depended on your ability to use knowledge of leaf structure in a new situation… If you got an incorrect answer, did you remember that stomata control exchange of oxygen, carbon dioxide, and water with the atmosphere? Did you understand that the amount of CO2 relative to O2 is problematic when the stomata are closed? Did you have trouble extending knowledge of leaf structure to determine the correct answer? 59) A
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Clarify Question What is the key concept addressed by the question? ● Can you a type of modified root? What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to the case of the red mangrove. Gather Content What do you already know about modified roots? What other information is related to the question? ● Aerial roots, typical of epiphytes, extend into the air as an adaption to water loss. ● Pneumatophores are outgrowths from underwater roots that aid in oxygen uptake. ● Buttress roots are huge roots toward the base of trunks that provide considerable stability. ● Tubers, which may be roots or shoots, store starch. ● Prop roots are adventitious growing from the stem that provide support.Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● The legs of the walking tree are prop roots, growing down from the shoots to provide support. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use knowledge of modified roots in a new situation… If you got an incorrect answer, did you remember prop roots are adventitious roots (meaning they grow from the shoot), or that they are much thinner than buttress Version 1
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roots (which also provide support)? Did you have trouble extending understanding of modified roots to determine the correct answer? 60) Section Break 60.1) C 60.2) B 60.3) D 60.4) A 60.5) E
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Chapter 36 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) Closing the stomata for an extended period of time would lead to an increase in G3P in the mesophyll cells. ⊚ ⊚
true false
2) If the soil around a plant is treated with a fungicide, the plant may experience a decline in DNA synthesis. ⊚ ⊚
3)
true false
Cavitation would have no effect on translocation. ⊚ ⊚
true false
4) An application of too much fertilizer will negatively affect the movement of materials in the phloem. ⊚ ⊚
true false
5) If a mutation decreased the radius of a xylem vessel threefold, there would be an 81-fold increase in the volume of liquid moving through the vessel. ⊚ ⊚
true false
6) An increase in root pressure will result in the rapid release of abscisic acid (ABA) and the subsequent opening of the stomata. ⊚ ⊚
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7)
If the proton pumps of guard cell were damaged, transpiration would decrease. ⊚ ⊚
true false
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 8) The process by which water is "pulled" up through the xylem columns of plants as it evaporates out of the leaves is called A) respiration. B) transpiration. C) osmosis. D) an hydration. E) somatization.
9) The most important ion in controlling the movement of water into and out of the guard cells is A) sodium. B) hydrogen. C) carbon. D) nitrogen. E) potassium.
10)
Water is able to cross plant plasma membranes by a combination of A) osmosis and aquaporins. B) evaporation and diffusion. C) root pressure and turgidity. D) diffusion and phloem. E) transpiration and Casparian strips.
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11)
On a short-term basis, water loss in plants may be controlled by the A) bending of the petioles on the leaves. B) closing of the stele in the roots. C) closing of the stomata in the leaves to limit transpiration. D) opening of the stomata in the leaves to allow more carbon dioxide to enter. E) opening the Casparian strips in the roots.
12) Mangrove plants live in areas regularly flooded with salt water. Which of these is not a possible mechanism for controlling their salt balance? A) The roots block salt uptake. B) The succulent leaves contain large quantities of water that dilute salt that is absorbed. C) Absorbed salt is secreted from special salt glands. D) Modified roots emerge above the water level and help oxygen diffuse into the roots. E) Excess salt is stored in special tissues.
13) Some plants are able to endure frequent flooding events because they contain a tissue with loose parenchyma cells and large air spaces called A) xylem. B) spongy mesophyll. C) pneumatophores. D) aerenchyma. E) epidermal tissue.
14) Even in the absence of transpiration, some water can move into the roots and partially up the xylem columns. This phenomenon is due to
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A) flooding. B) stomatal opening. C) root pressure. D) proton pumps. E) phloem translocation.
15)
Which of the following statements does not apply to aquaporins? A) They are water transport channels. B) They are unique to plant cells. C) They occur in the plasma membrane. D) They speed up osmosis. E) They do not alter the direction of water movement.
16)
Which of the following statements about transport through phloem is true? A) Transport only occurs from the roots to the shoot. B) It is aided by root pressure. C) The direction of flow can change at different times if the sources and sinks change. D) No energy is required. E) Mostly dissolved starch is transported.
17) Which of the following is not transported within the plant by the xylem and/or the phloem? A) dissolved minerals B) sucrose C) growth-regulating hormones D) water E) starch
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18)
Turgor is most directly related to the plant cells' A) total water potential. B) pressure potential. C) solute potential. D) osmosis. E) gravity potential.
19)
Water moves through a plant by each of the following methods except A) from cell to cell through plasmodesmata. B) through the Casparian strip. C) through the spaces between cells. D) through vessel members. E) from cell to cell across plasma membranes.
20)
The movement of oxygen through the aquatic plant may depend on A) osmotic absorption by the roots. B) aquaporins. C) negative pressures created by transpiration. D) differences in the water potential of different tissues. E) aerenchyma tissue.
21)
Most of the water that evaporates from leaves passes out through the A) cuticle. B) ends of xylem vessels. C) epidermis. D) spaces between epidermal cells. E) stomata.
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22)
Most of the water absorbed by the plant enters through the A) root apical meristem. B) root cap. C) root hairs. D) stomata. E) lenticels.
23)
Stomatal opening requires each of the following conditions, except A) expenditure of energy. B) a reduction of turgor in the guard cells. C) water entering the guard cells by osmosis. D) a lower water potential in the guard cells. E) pumping of potassium ions into the guard cells.
24) The plasma membranes of root hair cells contain a variety of protein transport channels through which specific ions are transported, even against large concentration gradients, by A) electron pumps. B) carbohydrate pumps. C) water pumps. D) proton pumps. E) root pumps.
25)
A plant will usually wilt when which component of water potential reaches 0 MPa? A) solute potential B) turgor pressure C) total water potential D) gravity potential
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26)
Cavitation can occur when what happens? A) Root pressure pushes water up the xylem. B) Starch grains block the sieve tubes. C) Gas bubbles expand inside a tracheid or vessel member. D) Stomata get stuck closed. E) Clouds block sunlight shining on the leaves.
27)
Which of the following actions occurs in many plants when CO2 concentrations are high? A) Guard cells lose turgor, and the stomata close. B) Water evaporates at a higher rate than usual. C) CAM photosynthesis fixes CO2 at night. D) Oxygen is used by plants for photosynthesis. E) Calcium ions are transported faster through the phloem.
28) The Calvin Cycle can only produce sugar if_________blank can enter through the pores of the leaves. A) O2 B) CO2 C) water D) potassium E) N2
29)
Plants living in standing water often face which of the following problems?
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A) increased CO2 levels B) chilling of the roots C) oxygen deprivation D) loss of stomata E) harmful root pressure
30) A plant is exposed to a toxin that blocks ABA receptor sites in the plasma membrane. What is the likely consequence of this exposure? A) Oxygen deprivation will trigger the release of ethylene, which will in turn suppress root growth. B) Gibberellin production will increase, allowing the plant to access more nutrients in the soil. C) ABA will enter the cells by an alternative route and normal function will be restored. D) The plant will lose excess water through transpiration and suffer dehydration. E) The guard cells will become flaccid and gas exchange will cease.
31) Which of the following must occur in order to maintain a high-pressure potential within guard cells? A) Potassium ions must be actively transported out. B) Energy must be constantly expended. C) Water must exit guard cells by osmosis. D) Stomata must take up more oxygen and less carbon dioxide. E) The rate of transpiration must increase.
32)
Mechanisms that evolved in plants to regulate the rate of water loss do not include
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A) becoming dormant during dry times of the year. B) losing leaves. C) producing leaves that are thick and hard. D) containing stomata in crypts or pits. E) increasing the number of water vacuoles in the cells.
33) The uneven distribution of an impermeable solute on either side of a membrane will result in A) an increase in oxygen deprivation. B) proton pumping. C) root pressure. D) osmosis. E) stomatal closing.
34) Most carbohydrates manufactured in leaves and other photosynthetic parts are transported through the phloem to the rest of the plant by the process of A) transpiration. B) translocation. C) osmosis. D) receptor-mediated transport. E) turgor pressure.
35)
Which of the following does not require expenditure of energy? A) accumulation of ions inside a cell B) transport against a concentration gradient C) flow of sucrose and other carbohydrates once inside the sieve tubes D) the loading and unloading of carbohydrates from the sieve tubes E) opening or closing stomata
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36)
Which of the following hormones increases when plants are flooded? A) gibberellin B) auxin C) ethylene D) cytokinin E) abscisic acid
37)
Some plants can tolerate flooding conditions by A) formation of aerenchyma. B) opening their lenticels. C) forming additional adventitious roots. D) shedding their bark. E) pumping water out of their roots.
38) The process of moving water through a plant by transpiration works because water molecules stick to each other with A) turgor pressure. B) osmosis. C) ionic bonds. D) adhesion. E) hydrogen bonds.
39)
Which of the following equations represents the total water potential of a plant? A) s2 + p2 = w2 B) ψs = ψp + ψw C) ψp = ψw + ψs D) ψw = ψp + ψs E) ψw = ψp _ ψs
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40)
Pure water without applied pressure has a water potential that is equal to A) infinity. B) 0.0 MPa. C) 1.6 MPa. D) -2.0 MPa. E) atmospheric pressure.
41)
Water molecules can "stick" to certain surfaces by A) adhesion. B) cohesion. C) root pressure. D) water pressure. E) pneumatophores.
42) Water may be lost in the form of liquid from the surface of leaves through a process known as A) guttation. B) cohesion. C) phloem loading. D) mesophyll adhesion. E) aeration.
43)
The pressure-flow hypothesis describes
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A) how hormones move through the phloem. B) how carbohydrates enter the sieve tubes. C) how carbohydrates in solution move through the phloem. D) how water and minerals move through the xylem. E) how carbohydrates and minerals move through the xylem.
44)
Most often, the largest gradient in water potential is between A) roots and soil water. B) root xylem and shoot xylem. C) xylem and phloem. D) leaf cells and the intracellular spaces inside the leaves. E) the relative humidity inside the leaf and the relative humidity outside the plant.
45)
Mycorrhizal fungi interact with plants at the A) stomata. B) seed coat. C) roots. D) edge of ponds. E) cuticle.
46) A large watermelon fruit is very heavy and contains nearly 90% water. Since the skin of a watermelon is thick and lacks stomata, transpiration does not "pull" water into the watermelon. So, how does all that water get into the fruit? A) Root pressure pushes water into the watermelon. B) Water enters by osmosis from the soil. C) Water is pumped in by active transport. D) Water is transported in the phloem along with the sugars while they are being translocated into the fruit. E) Watermelons, like other fruit, contain an abundance of xylem.
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47) Which of these structures is not likely to contain significant amounts of aerenchyma tissue? A) mangrove pneumatophores B) rice roots C) water lily leaves D) cypress "knees" E) coconut tree roots
48) Halophytes are plants that live in saline soils. The high osmotic potential of the salt solution in the soil creates a very negative water potential. What can halophytes do so that water will flow into the roots? A) They can close their stomata so that less water is lost through transpiration. B) They can open all their stomata so that transpiration "pulls" more water into the roots. C) They can increase the solute concentration in their roots creating a water potential that is more negative than the soil. D) They can pump ions out of the plant creating a water potential in the roots that is more positive than the soil. E) They can remove the mycorrhizal fungi from their roots decreasing the competition for water.
49)
Which of these situations regarding phloem sources and sinks is not correct? A) The root of a carrot plant is a source. B) Young leaves are sinks. C) A growing pumpkin is a sink. D) In a seedling, the cotyledons would be sources. E) During autumn, deciduous tree roots would be a sink.
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50) You a given a plant tissue in lab and asked to determine if the tissue is a source or a sink. Microscopic analysis reveals an abundance of colorless parenchyma cells with plastids. Only one biochemical test reacts positively with your sample. In the presence of iodine, the plastids turn a dark purplish color. Based on this information you determine your sample is A) a source because your sample is rich in carbohydrates. B) a source because your sample contains plastids. C) a sink because your sample is rich in carbohydrates. D) both a source and sink because it contains both plastids and carbohydrates.
51) Mimosa pudica, sometimes called the sensitive plant, is able to rapidly move its leaves in response to touch. The leaves are connected to the stem by a flexible joint called a pulvinus. Touching the leaves results in a flow of ions out of the symplast of the inner cells of the pulvinus and an upregulation of aquaporins. How does this affect the water potential and the movement of water? [Insert image] A) The solute potential in the inner cells decreases and the water flows out of those pulvinus cells into the apoplast. B) The pressure potential in the inner cells increases and water flows into those pulvinus cells. C) The solute potential in the inner cells increases and the water flows into those pulvinus cells. D) The water potential in the apoplast increases and the water flows out of those pulvinus cells. E) The pressure potential in the apoplast decreases and the water flows out of those pulvinus cells.
52)
Which of the following statements about routes of travel through a plant is correct?
A) Dissolved minerals moving from roots to leaves in vessels are in the apoplast. B) Water can move from a root hair to the stele in the apoplast route. C) Sugars moving from a source to a sink in sieve-tube elements are in the apoplast. D) Movement from apoplast to symplast in an endodermal cell requires active transport. E) Dissolved ions in the symplast of an endodermal cell require a membrane protein to cross the Casparian strip.
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53) You may understandably think that maple syrup is made by tapping the sucrose-rich phloem sap, but in fact it is sap from dead cells located further into the trunk that is harvested and distilled to make this sweet pancake topping. The movement of sugar into the apoplast involves starches stored in the stem, hydrolyzed into sucrose in the spring, and moved into the sap. The sap is harvested only in the spring when the nights are below freezing and the days are warm, a situation which causes the sap to repeatedly expand (thus rising up the stem) and contract. If you wanted to make some maple syrup, what type of cell would you need to tap to get the sap? A) Vessels B) Vascular cambium C) Companion cells D) Sieve tube elements E) Mesophyll
54)
Which of the following cannot be used to move substances into vascular tissue? A) Active transport water from the apoplast into a vessel. B) Active transport sugar from the apoplast into a sieve-tube member. C) Active transport ions into a sieve tube member so that water will move into the cell. D) Passive transport water from endodermis cell to vessel. E) Passive transport sugar from mesophyll to sieve-tube member via symplast route.
SECTION BREAK. Answer all the part questions. 55) Consider the following plant cells floating in an open beaker containing 0.2M sucrose. By definition, an open beaker has a pressure potential of 0 MPa. Assume that the cells have come to equilibrium with the solution in the beaker. Component Solute potential
Beaker -0.5 MPa
Cell 1 -1.0 MPa
Cell 2 -0.75 MPa
Cell 3 -0.5 MPa
Ψs
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Pressure potential
0.0 MPa
?
?
?
-0.5 MPa
?
?
?
Ψp
Total water potential
Ψw
55.1)
In Cell 1,
A) ψp = 0.0 MPa and ψw = 0.0 MPa. B) ψp = 0.0 MPa and ψw = -1.0 MPa. C) ψp = +0.5 MPa and ψw = -0.5 MPa. D) ψp = -0.5 MPa and ψw = -0.5 MPa. E) ψp = 0.0 MPa and ψw = +0.5 MPa.
55.2)
In Cell 2,
A) ψp = 0.75 MPa and ψw = 0.0 MPa. B) ψp = 0.0 MPa and ψw = -0.75 MPa. C) ψp = -0.25 MPa and ψw = -0.5 MPa. D) ψp = +0.25 MPa and ψw = -0.5 MPa. E) ψp = +0.25 MPa and ψw = +0.25 MPa.
55.3)
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A) ψp = 0.0 MPa and ψw = -0.5 MPa. B) ψp = 0.0 MPa and ψw = 0.0 MPa. C) ψp = +0.5 MPa and ψw = -0.5 MPa. D) ψp = -0.5 MPa and ψw = -0.5 MPa. E) ψp = 0.0 MPa and ψw = +0.5 MPa.
56) Choose the letter of the best match from the following: A. abscisic acid B. trichomes C. aquaporin D. endodermis E. stoma
56.1)
Pore in plasma membrane that allows water movement.
56.2)
Triggers K+ to pass rapidly out of guard cells.
56.3)
Pore in leaves that regulates gas exchange.
56.4)
Regulates movement of mineral ions into root xylem.
56.5)
Reflects sunlight at leaf surface.
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Answer Key Test name: Chap 36_13e_Raven 1) FALSE While the stomata are closed, gases cannot be exchanged. As a consequence, oxygen levels rise and carbon dioxide levels decrease within the plant. Without carbon dioxide, the Calvin Cycle lacks the material to produce G3P, the precursor to glucose. Refer to section 36.4 for more information on stomata. 2) TRUE
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Clarify Question What is the key concept addressed by the question? ● The key concept is the role of fungi in the life of plants. What type of thinking is required? ● You are being asked to take what you already know and apply it to a new situation in which fungi are removed from their plant symbionts. What key words does the question contain and what do they mean? ● Fungicide, which is a chemical that kills fungi. ● DNA, which is the genetic material of living things. ● Synthesis, which means to produce. Gather Content What do you already know about the role that fungi play in plant cell function? How does it relate to the question? ● Mycorrhizal fungi are associated with the roots of certain plants. ● Myco refers to fungi, while rhizzal pertains to roots. ● These fungi aid the absorption of water and minerals from the soil. ● Phosphorus absorption from the soil is especially enhanced. ● Phosphorus is an important building block of DNA. Consider Possibilities What other information is related to the question? Which information is most useful? ● Since DNA synthesis is dependent on available building blocks, mycorrhizal fungi would aid this process by making phosphorus available. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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● To answer this question, you must connect the concept of associating with mycorrhizal fungi, the minerals they make available, and the role those minerals play in DNA synthesis. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to identify the contributions of mycorrhizal fungi to plant biology. Answering this question correctly depended on your ability to use the idea that these fungi contribute minerals to plants in a new situation… If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that these fungi make phosphorus available, or that phosphorus is a building block of DNA? Did you have trouble extending this benefit of mycorrhizal association to determine the correct answer? 3) FALSE
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Clarify Question What is the key concept addressed by the question? ● The concept in this question is cavitation and its effects on a plant. What type of thinking is required? ● You are being asked to take what you already know and apply it to the effects of cavitation. What key words does the question contain and what do they mean? ● Cavitation, which is the blockage of xylem. ● Translocation, which refers to the movement of nutrients through a plant. Gather Content What do you already know about cavitation in plants? How does it relate to the question? ● Xylem carries water through plant tissue. ● Phloem carries nutrients through plant tissue. ● Water flows from xylem to phloem, since the water potential in xylem is greater. ● Phloem relies on the influx of water to push nutrients into tissues. ● Cavitation refers to the presence of an air bubble in xylem. ● If a xylem vessel is blocked, associated phloem will be impeded too. Consider Possibilities What other information is related to the question? Which information is most useful? ● Content specific to key concept. Choose Answer Given what you now know, what information and/or problem solving Version 1
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approach is most likely to produce the correct answer? ● If water flow is blocked, nutrient flow will be blocked as well. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to apply what you know about cavitation. Answering this question correctly depended on your ability to use cavitation and its effects on translocation in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that cavitation stops the flow of water in xylem, or that if a xylem vessel is blocked, associated phloem will be impeded in function? Did you have trouble extending these ideas of cavitation and translocation to determine the correct answer? 4) TRUE
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Clarify Question What is the key concept addressed by the question? ● For water to move into plant roots, the water potential must be less inside of the plant than it is outside of the plant. What type of thinking is required? ● You are being asked to take what you already know and apply it to the effects of changing tonicity in the soil around a plant. What key words does the question contain and what do they mean? ● Fertilizer, which is an applied substance that increases plant growth. ● Phloem, which is vascular tissue that transports nutrients. Gather Content What do you already know about water potential and how it effects the movement of water in plants? How does it relate to the question? ● Adding fertilizer to the soil increases the solute concentration of the soil. ● If the solute concentration of the soil is too high, the water potential will decline below that of the plant. ● If the water potential is lower outside of the plant, water will flow out of the plant. ● If water flows out of the plant, it will not be drawn into the xylem. ● If water flow in the xylem ceases, the phloem will also be affected. ● Without water flow from the xylem, nutrients will not be pushed from the phloem into the tissue. Consider Possibilities What other information is related to the question? Which information is most useful? ● Since fertilizer is a solute, adding it to the soil would affect the Version 1
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tonicity of the soil, which will affect water flow in the plant. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● You need to connect the presence of fertilizer with increased tonicity. ● Increased tonicity in the soil can result in water loss from the plant. ● With water loss, the flow of water and nutrients in the xylem and phloem are impeded. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to predict the effects of increasing tonicity by the additional of fertilizer. Answering this question correctly depended on your ability to use your knowledge of water flow in a new situation… If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that water flows into xylem under normal conditions, or that water in the xylem flows into the phloem,, which pushes nutrients into the tissues? Did you have trouble extending these ideas of nutrients and water flow to determine the correct answer? 5) FALSE
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Clarify Question What is the key concept addressed by the question? ● The key concept is the relationship between vessel radius and volume through the vessel. What type of thinking is required? ● You are being asked to take what you already know and apply to a new situation. What key words does the question contain and what do they mean? ● Xylem, which is the vascular tissue that carries water through a plant. ● Mutation, which refers to a mistake or misreading in the genetic material. Gather Content What do you already know about the relationship between the radius and volume in a vessel? How does it relate to the question? ● Xylem carries water through plant tissue. ● As the radius of xylem increases, the volume increases by r4. Consider Possibilities What other information is related to the question? Which information is most useful? ● A decrease in the radius of xylem would decrease volume. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● You need to connect the idea that an increase in radius is linked to an increase in volume. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● This question asked you to relate the concept of increasing xylem radius to increasing volume. Answering this question correctly depended on your ability to use the relationship between xylem radius and volume to a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that as xylem radius increases, volume increases by r4? Did you have trouble extending this direct relationship to determine the correct answer? 6) FALSE
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Clarify Question What is the key concept addressed by the question? ● The key concept is root pressure. What type of thinking is required? ● You are being asked to take what you already know and apply it to changing root pressure in a plant. What key words does the question contain and what do they mean? ● Root pressure is an accumulation of ions in root tissue, which causes an influx of water. ● ABA is a plant hormone that causes stomata to close. ● Stomata are openings on leaves that allow gas exchange to occur. Gather Content What do you already know about root pressure and its effect on ABA? How does it relate to the question? ● Increasing root pressure causes guttation, which is the loss of water from small veins in the leaf. ● Guttation bypasses the stomata. Consider Possibilities What other information is related to the question? Which information is most useful? ● ABA acts to close the stomata. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● If you connect root pressure to guttation and not ABA and stomata, you will arrive at the correct answer. Version 1
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to separate the effects of root pressure from those of ABA. Answering this question correctly depended on your ability to use root pressure in a new situation… If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that root pressure is connected to guttation, or that guttation is unrelated to the stomata? Did you have trouble extending root pressure to determine the correct answer? 7) TRUE
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Clarify Question What is the key concept addressed by the question? ● The key concept is transpiration. What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to proton pumps and transpiration. What key words does the question contain and what do they mean? ● Proton pump, which creates a proton gradient across a membrane, and thereby stores potential energy. ● Transpiration, which is the evaporation of water in the stomata. ● Guard cell, which is a cell that opens and closes the stomata. Gather Content What do you already know about the relationship between guard cells and transpiration? How does it relate to the question? ● Guard cells require ATP to actively transport ions. ● Proton pumps are used in this active transport. ● As ions move in, so does water. ● Water increases the turgor of the guard cells. ● Increased turgor in guard cells opens the stomata. ● Open stomata allow transpiration to occur. Consider Possibilities What other information is related to the question? Which information is most useful? ● If proton pumps are damaged, guard cells could not stockpile ions, and so they would not fill with water. If guard cells do not fill with water, the stomata remain closed. If guard cells remain closed, transpiration would not occur. Version 1
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Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● To answer this question, you need to connect the function of the proton pumps to the opening of the stomata. Once the stomata are open, transpiration can occur. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to connect proton pump function with guard cells and transpiration. Answering this question correctly depended on your ability to use the mechanics of transpiration in a new situation… If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that the opening of guard cells requires the build up of ions via the use of proton pumps, or that if guard cells do not open, transpiration cannot occur? Did you have trouble extending transpiration to determine the correct answer? 8) B Transpiration is evaporation of water through the stomata. Because water molecules stick to one another through cohesion, as one water molecule evaporates it pulls other water molecules up toward the stomata. Refer to section 36.1 for more information on transpiration. 9) E The hormone ABA triggers the outflux of potassium from guard cells. As the potassium exits the guard cells water follows. This results in a loss of turgor pressure and the cells cover the stomatal opening. Please refer to section 36.4 for more information. Version 1
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10) A Water moves from regions of higher pressure to lower pressure (osmosis). In cells, this movement of water is facilitated by small membrane channels called aquaporins. These channels allow water, which is a polar molecule, to rapidly cross the nonpolar cell membrane. Please refer to section 36.1 for more information. 11) C When water needs to be conserved, guard cells block the openings of the stomata. This prevents water loss due to transpiration. Please refer to section 36.4 for more information on guard cells. 12) D Many plant adaptations have evolved for dealing with salt in the environment. Please read section 36.5 for more information on these adaptations. 13) D Aerenchyma is a tissue composed of loose parenchyma cells intermixed with large air spaces. The tissue functions in transporting oxygen to the parts of the plant that are submerged. Please read section 36.5 for more information. 14) C Root pressure is due to osmosis in the roots. The roots continue to accumulate ions even when the plant is not transpiring. Because the roots have such a high ion concentration, water enters via osmosis and enters the xylem. Please read section 36.3 for more information. 15) B Aquaporins occur in both plant and animal cells. Please refer to section 36.1 for more information.
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16) C Sources and sinks change through time and therefore, the direction of phloem flow changes. Please read section 36.6 for more information. 17) E Sugars produced from photosynthesis are transported from the source via the phloem to storage areas (sinks) within the plant. Some sugars are then converted to starch for storage. If the plant needs to access its sugar stores, the starch is converted back to transportable molecules like sucrose. Starch does not travel through the plant. Please refer to section 36.6 for more information. 18) B Turgor results from pressure against the cell wall. This pressure is also known as pressure potential. Turgor pressure increases as the pressure potential increases. Please refer to section 36.1 for more information. 19) B Casparian strips block water transport through cell walls of the endodermis. The strips force water through the plasma membranes and protoplasts of the endodermal cells. This controls water and nutrient flow into the xylem. Please refer to section 36.2 for more information. 20) E Aerenchyma is a tissue that has evolved in freshwater plants to facilitate the transport of oxygen from the above-water portion of the plant to the parts that are below the water. Aerenchyma is a loose parenchymal tissue with large air spaces. Please refer to section 36.5 for more information. 21) E
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The majority of water exits a plant through the stomata. Since water exits through the stomata, the plant can regulate water loss. The opening of the stomata are regulated by guard cells. When the plant needs to conserve water, the guard cells close the openings to the stomata. Please refer to section 36.1 and also 36.4 for more information. 22) C Regions of the root with root hairs absorb the most water. Root hairs, which are extensions of the epidermis, greatly increase the surface area of the root for absorption. Please refer to section 36.2 for more information. 23) B When guard cells absorb water and become turgid, the stomata are opened. When guard cells lose water and turgidity, the cells cover the stomatal opening which blocks transpiration. Refer to section 36.4 for more information. 24) D The endodermal cells of the root actively transport nutrients using proton pumps. Refer to section 36.2 for more information. 25) B When the pressure potential reaches 0 MPa within a cell, there is no more turgor pressure. This pressure is necessary to keep the cell wall rigid and to keep the plant from wilting. Please refer to section 36.1 for more information. 26) C A gas bubble in the xylem can block the movement of water through the plant. This can cause dehydration and even death of the plant. Please refer to section 36.3 for more information.
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27) A When carbon dioxide levels are high the stomata can close because the Calvin Cycle has the material needed to produce sugar. It is only when the cells are deficient in carbon dioxide that the stomata need to open. Please refer to section 36.4 for more information. 28) B The pores in the leaves are called stomata. When open, they allow the entry of carbon dioxide and the exit of oxygen. The carbon dioxide is fixed into sugar in the Calvin Cycle of photosynthesis. Please refer to section 36.4. 29) C Plants need oxygen for cellular respiration. Standing water does not contain as much oxygen as moving water. Plants that have evolved in habitats with standing water have adaptations that allow them to facilitate the flow of oxygen to the tissues below water. Please read section 36.5 for more information. 30) D
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Clarify Question ● What is the key concept addressed by the question?● The key concept is the function of ABA. ● What type of thinking is required?● Apply, because you must take what you know about ABA and apply it to a new situation. ● What key words does the question contain?● ABA receptor sites, which are molecules that receive ABA and signal the cell to open ion channels. Gather Content ● What do you already know about ABA? How does it relate to the question?● The hormone ABA is abscisic acid. ● ABA binds to receptors in the cell membrane. ● As a result, K+ and other ion channels open. ● This causes guard cells to lose K+. ● Water loss follows, and turgor pressure decreases. ● This causes guard cells to close. ● Closed guard cells become flaccid, and cover the openings of the stomata. ● This prevents excess water loss. Consider Possibilities ● What other information is related to the question? Which information is most useful?● ABA acts on the guard cells that surround the stomata, so root function is not impacted. ● If guard cells do not become flaccid, stomata will remain open, and gas exchange can occur. Choose Answer Version 1
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● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● As soon as you identify the function of ABA, you can deduce what would happen to a plant that did not have functional ABA receptors. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● This question requires you to connect what you know about ABA function in a normal plant with a sudden loss of ABA activity due to the toxin. First, you must recognize that ABA functions in guard cells that surround the stomata of the leaf. When you recall that ABA causes the stomata to close, you know that by closing, the stomata are preventing excess water loss. Therefore, if ABA is not received by the guard cells, the cells will remain open, which would allow evaporation of water without limit. 31) B
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Clarify Question ● What is the key concept addressed by the question?● The key concept is the mechanical function of the guard cells. ● What type of thinking is required?● Apply, because knowledge of how the guard cells function must be applied to a different concept. ● What key words does the question contain?● High pressure potential, which is a high hydrostatic pressure inside a cell. ● Guard cells, which open and close stomata on the leaf surface. Gather Content ● What do you already know about how guard cells function? How does it relate to the question?● High pressure potential is directly related to turgor. ● Turgor is maintained in plant cells by the active uptake of K+ and other ions. ● As solute concentration increases through this active uptake, water potential decreases. ● Water flows into the cell, toward the area of lower water potential. ● This and any active process requires the use of energy. Consider Alternatives ● What other information is related to the question? Which information is most useful?● Gas exchange is not directly related to the mechanics of the guard cells. ● Any loss of water or ions would cause the guard cells to lose turgor and pressure potential. Choose Strategy ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● To answer this Version 1
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question you must connect the concepts of pressure potential and turgor. To maintain turgor, ions must be actively transported (using ATP) into the cell. This lowers the water potential, which brings water in and increases turgor and the pressure potential. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● The question is asking you to relate the active uptake of ions with increased turgor. If you arrived at the correct answer, well done! If you came up with an incorrect answer, where did the process break down? Did you remember that as pressure potential increases, turgor increases? Turgor is maintained by the active uptake of K+ and other ions. 32) E Section 36.5 describes plant adaptations to limit water loss. Increasing the number of water vacuoles would provide water storage for cells but would not prevent water loss via transpiration. 33) D The side of the membrane with the most solute would be hypertonic relative to the other side. This means water would flow via osmosis towards the side with the most solute. Please refer to section 36.1 for more information. 34) B Translocation is the process where the carbohydrates manufactured during photosynthesis are transported from the leaves and other green parts to the rest of the plant. This is a function of the phloem. Section 36.6 discusses translocation.
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35) C Once inside the sieve tubes, water flows via osmosis from xylem into the phloem. This raises the pressure within the tubes and this pressure moves the material through the phloem. Section 36.6 discusses this in more detail. 36) C A plant that is experiencing flooding will release ethylene, a hormone that suppresses root growth. Please refer to section 36.5 for more information. 37) A Flooding reduces oxygen availability to the plant. Many plants that have evolved in environments with standing water have a tissue called aerenchyma. This tissue contains large air spaces that helps facilitate the flow of oxygen from the parts of the plant above water to those parts submerged in water. Please refer to section 36.5 for more information. 38) E Cohesion is the attraction of one water molecule to another. This attraction is caused by the formation of hydrogen bonds. Water is a polar molecule which means that part of the molecule has a weak positive charge and part of it has a weak negative charge. When the positive charge on one water molecule is attracted to a weak negative charge on another water molecule, a hydrogen bond forms. 39) D The total water potential of a cell is the sum of its pressure potential and solute potential. Please read section 36.1 for more information. 40) B Since pure water does not have any solutes, it does not have any solute potential. Section 36.1 discusses water potential. Version 1
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41) A Adhesion is when a water molecule is attracted to something other than another water molecule. Water molecules are attracted via adhesion to the walls of the xylem vessels. Section 36.1 discusses adhesion and cohesion. 42) A Guttation occurs when root pressure is so strong that it forces water up to the leaves. Section 36.3 discusses guttation. 43) C The pressure-flow hypothesis describes how carbohydrates flow from a source to a sink. This topic is discussed in section 36.6. 44) E The driving force of transpiration is the gradient that exists between the outside of the leaf (low humidity) and the inside of the leaf (high humidity). Please refer to section 36.3. 45) C Mycorrhizal fungi interact with the roots of many species of plants. They extend the surface area for absorption of water and nutrients and therefore are beneficial to the plant. See section 36.2. 46) D
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Clarify Question What is the key concept addressed by the question? ● The key concept in this question is the movement of water into a fruit. What type of thinking is required? ● You are being asked to take what you already know and apply it to the heavy water content of a fruit. What key words does the question contain and what do they mean? ● Stomata are small opening on leaves that allow gas exchange to occur, but also allow water loss through evaporation. ● Transpiration, which is the process of pulling water into a plant through the roots via the evaporation of water through the leaves. Gather Content What do you already know about how water moves through the tissues in a plant? How does it relate to the question? ● The question tells you that water cannot enter the watermelon through transpiration or through the stomata. You know that the phloem is heavy in solutes, as it carries sugars and other nutrients in a water-based solution. Since this material in the phloem is solute-heavy, it is hypertonic, and has lower water potential. Solutions with lower water potential such as this would receive water from surrounding tissues, which would have higher water potential. Consider Possibilities What other information is related to the question? Which information is most useful? ● Actively transporting water into a watermelon would be energetically costly and unnecessary. Xylem already inside the watermelon would not help to transport water into the watermelon. The question tells you that the skin of the watermelon is thick, so that would not promote the Version 1
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movement of water from the soil directly into the watermelon. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● The question itself tells you it is not feasible for water to flow directly from the environment into the watermelon due to the thick skin and lack of stomata on the watermelon. To answer this question, you must recall the internal consistency of the watermelon. The watermelon becomes a sink for the hypertonic sap that is carried in the phloem. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to take what you know about the flow of materials within a plant, and apply it to the synthesis of fruit. Answering this question correctly depended on your ability to use the nature of the fluid within the phloem in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that the fluid within the phloem is hypertonic, or that the skin of a watermelon is too thick to allow water to flow in? Did you have trouble extending the nature of the fluid in the phloem to determine the correct answer? 47) E Plants that have roots that grow in water would likely have aerenchyma tissues. Coconut trees do not grow in the water. Please refer to section 36.5 for more information on plant adaptations to water-stress. 48) C
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Clarify Question What is the key concept addressed by the question? ● The question addresses adaptations of plants that live in high salt environments. What type of thinking is required? ● You are being asked to take what you already know to explain how certain plants can cope with an extreme environment. What key words does the question contain and what do they mean? ● Halophytes, which are plants that can tolerate high salt conditions. ● Saline, which refers a salty environment. ● High osmotic potential, which is a high solute concentration. ● Negative water potential, which is a lower proportion of water. Gather Content What do you already know about the adaptations that occurs in plants that live in salty environments? How does it relate to the question? ● In salty soil, the water potential inside the plant is higher than that outside, so plants dry out. ● Halophytes are salt-loving plants, which can tolerate much higher levels of salt in the soil compared to other plants. ● Some halophytes add extra ions to their root tissue. ● The addition of excess ions in the root reverses the usual water potential gradient. ● Water flows into the plant, from high to low water potential. Consider Possibilities What other information is related to the question? Which information is most useful? ● Stomata must be able to open at some point, or gas exchange would be Version 1
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negatively impacted. ● If stomata were consistently to remain open, too much water loss would occur. ● A loss of ions would negatively impact the physiology of the plant. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● Plants must have water enter through the roots. Water flows from high water potential to low water potential. In salty soil, the water potential gradient causes water to flow out of plants. Halophytes reverse this gradient by pumping ions into the root tissue, thereby creating a lower water potential inside the root. This makes water flow into the roots of halophytes. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● This question asked you to explain how a halophyte survives extreme conditions. Answering this question correctly depended on your ability to use concept your knowledge of halophytes and water potential in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that water potential is greater inside the root of a plant in salty soil, but halophytes can reverse this gradient? Did you have trouble extending the concept of water potential to determine the correct answer? 49) B
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A source is a photosynthetic tissue that produces sugars. Sinks are the parts of a plant where the sugar is utilized. Please refer to section 36.6 for more information. 50) C
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Clarify Question What is the key concept addressed by the question? ● The key concept is that a sink can be differentiated by the presence of stored carbohydrates. What type of thinking is required? ● You are being asked to take what you already know apply it to the analysis of unknown tissue to determine whether the tissue is a source or a sink. What key words does the question contain and what do they mean? ● Source, which is the part of the plant that is photosynthetic. ● Sink, which is the part of the plant that uses or stores carbohydrates. ● Iodine, can be used as an indicator for starch. Gather Content What do you already know about the function of a sink in a plant? How does it relate to the question? ● Colorless tissue is not photosynthetic. ● The product of photosynthesis is glucose. ● Glucose is stored by plants as starch. ● A positive iodine test for starch turns blue black in color. Consider Possibilities What other information is related to the question? Which information is most useful? ● Content specific to key concept. Choose Answer Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● Sources are photosynthetic, so they are green in color. They would not Version 1
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contain colorless plastids. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● This question asked you to apply what you know about sources and sinks to a sample of unknown origin. Answering this question correctly depended on your ability to use these ideas about sources and sinks in a new situation… If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that sinks are sites of carbohydrate use and storage, or that iodine indicates starch by turning blue-black? Did you have trouble extending these concepts to determine the correct answer? 51) A
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Clarify Question What is the key concept addressed by the question? ● How does changing solute concentration affect the movement of water? What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to predict the movement of water in a plant. Gather Content What do you already know about water potential? What other information is related to the question? ● Water will always move from a cell with higher water potential to a cell with lower water potential. ● The total water potential of a plant cell is the sum of its pressure potential and its solute potential. ● As a solution increases in solute concentration, it decreases in solute potential. ● As ions are pumped out of the pulvinus cells, the solute potential increases. ● Aquaporins are transport proteins that increase the rate of osmosis, but don’t affect its direction. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● As the solute potential increases in the pulvinus cells, water moves out into the apoplast. The upregulation of aquaporins increases the rate at which this happens. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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● Answering this question correctly depended on your ability to use water potential in a new situation. If you got an incorrect answer, did you remember that removing ions from the pulvinus cells through an aquaporin would move them into the apoplast, or that adding ions to the apoplast would decrease the solute potential and cause water to leave the pulvinus cells? Did you have trouble extending the concept of water potential to determine the correct answer? 52) A
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Clarify Question What is the key concept addressed by the question? ● Can you identify a true statement about transport routes in a plant? What type of thinking is required? ● This question is asking you to weight and judge, or evaluate, five statements about they routes of travel through a plant. Gather Content What do you already know about transport in a plant? What other information is related to the question? ● The apoplast route includes movement through the cell walls and the space between cells. The symplast route is the continuum of cytoplasm between cells connected by plasmodesmata. ● Vessels are dead at maturity, so any water and dissolved substances are in the apoplast. ● Sieve-tube elements are living cells, so sugars transported by them are in the symplast. ● Water moving from a root hair to the stele in the apoplast route will be blocked by the Casparian strip and will need to move into the symplast of an endodermal cell. ● Movement from apoplast to symplast for ions would require a transport protein, but active transport is only required if the ion is moving up its concentration gradient. ● The Casparian strip closes the apoplast in the endodermal cells, so substances must move across from the symplast through plasmodesmata. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Since dissolved minerals moving from roots to shoots are in vessels, they are moving in spaces between the cell walls (the apoplast route) not Version 1
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inside the cytoplasm of cells (the symplast route). Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to weight and judge, or evaluate, the movement of material through a plant. If you got an incorrect answer, did you remember that the apoplast route includes movement through cell walls and the space between cells, or that this includes vessels, since they are dead at maturity? Did you have trouble comparing symplast and apoplast to determine the correct answer? 53) A
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Clarify Question What is the key concept addressed by the question? ● What types of cells transport maple sap? What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to the harvesting of maple sap. Gather Content What do you already know about plant transport? What other information is related to the question? ● Phloem is composed of living cells called sieve tube members that transport sugars and companion cells that support them. ● Xylem is composed of dead cells called vessels (or tracheids) that transport sugar and dissolved substances. ● In trees, xylem is found on the interior of the vascular cambium and phloem is found to the exterior. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Dead cells located further into the trunk that can transport water with dissolved sugars are xylem cells. Vessels are a type of xylem cell. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use knowledge of vascular tissue a new situation. If you got an incorrect answer, did you remember that xylem cells are vascular cells that are dead at maturity, or that vessels are a type of xylem cell? Did you have trouble extending knowledge of vascular tissue to determine the correct
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answer? 54) A
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Clarify Question What is the key concept addressed by the question? ● How are materials transported into vascular tissue? What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to identify an incorrect statement about loading into xylem or phloem. Gather Content What do you already know about moving substances into vascular tissue? What other information is related to the question? ● Xylem is vascular tissue that moves water and dissolved substances through a plant. The cells, called vessels and tracheids, are dead at maturity. ● Phloem is a vascular tissue that moves sugars through a plant. The cells, called sieve tube members and companion cells, are living at maturity. ● Moving substances into a living cell requires movement over the cell membrane. When the substance is moving down its concentration gradient, it is passive transport. When the substance is moving up its concentration gradient, it requires energy and is called active transport. ● Water moves by osmosis (passive transport) from higher to lower water potential. ● Nothing can move by active transport from apoplast to vessels, since the dead vessel cells do not have a cell membrane. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Nothing can move by active transport from apoplast to vessels, since the dead vessel cells do not have a cell membrane. Reflect on Process Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use knowledge of vascular tissue in a new situation. If you got an incorrect answer, did you remember that passive and active transport both involve movement over a cell membrane, or that vessels do not have a membrane since they are dead at maturity? Did you have trouble extending knowledge of vascular tissue to determine the correct answer? 55) Section Break 55.1) C
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Clarify Question What is the key concept addressed by the question? ● The key concept in this question is water potential. What type of thinking is required? o You are being asked to take what you already know and use, or apply, it to water potential in a cell. What key words does the question contain and what do they mean? ● Water potential, which refers to the potential energy of a solution. ● Pressure potential, which is the outward pressure exerted by the water in a cell. ● Solute potential, or the pressure that is a result of the solute molecules that are present. Gather Content What do you already know about water potential? How does it relate to the question? ● Water potential is equal to solute pressure plus pressure potential. ● Solute potential is always negative. ● As solute increases, solute potential decreases. ● Decreasing solute potential causes a decrease in water potential. Consider Possibilities What other information is related to the question? Which information is most useful? ● Recall that numerically solute potential and pressure potential must together equal water potential. Choose Answer Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer? ● In cell 1, the solute potential is given as -1.0MPa. To solve this problem, you must select a choice that takes this given solute concentration into consideration. There is only one choice in which water potential equals the sum of solute potential and pressure potential. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? The question is asking you to deduce the water potential and pressure potential for a given cell, given the solute potential. If you arrived at the correct answer, well done! If you came up with an incorrect answer, where did the process break down? Did you remember that water potential must equal the sum of pressure potential and solute potential? 55.2) D
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Clarify Question What is the key concept addressed by the question? ● The key concept in this question is water potential. What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to water potential in a cell. What key words does the question contain and what do they mean? ● Water potential, which refers to the potential energy of a solution. ● Pressure potential, which is the outward pressure exerted by the water in a cell. ● Solute potential, or the pressure that is a result of the solute molecules that are present. Gather Content What do you already know about water potential? How does it relate to the question? ● Water potential is equal to solute pressure plus pressure potential. ● Solute potential is always negative. ● As solute increases, solute potential decreases. ● Decreasing solute potential causes a decrease in water potential. Consider Possibilities What other information is related to the question? Which information is most useful? ● Recall that numerically solute potential and pressure potential must together equal water potential. Choose Answer
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Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● In cell 1, the solute potential is given as -0.75 MPa. To solve this problem, you must select a choice that takes this given solute concentration into consideration. There is only one choice in which the number for water potential equals the sum of solute pressure and pressure potential. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? The question is asking you to deduce the water potential and pressure potential for a given cell, given the solute potential. If you arrived at the correct answer, well done! If you came up with an incorrect answer, where did the process break down? Did you remember that water potential must equal the sum of pressure potential and solute potential? 55.3) A
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Clarify Question What is the key concept addressed by the question? ● The key concept in this question is water potential. What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to water potential in a cell. What key words does the question contain and what do they mean? ● Water potential, which refers to the potential energy of a solution. ● Pressure potential, which is the outward pressure exerted by the water in a cell. ● Solute potential, or the pressure that is a result of the solute molecules that are present. Gather Content What do you already know about water potential? How does it relate to the question? ● Water potential is equal to solute pressure plus pressure potential. ● Solute potential is always negative. ● As solute increases, solute potential decreases. ● Decreasing solute potential causes a decrease in water potential. Consider Possibilities What other information is related to the question? Which information is most useful? ● Recall that numerically solute potential and pressure potential must together equal water potential. Choose Answer
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Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? ● In cell 1, the solute potential is given as -0.50 MPa. To solve this problem, you must select a choice that takes this given solute concentration into consideration. There is only one choice in which the number for water potential equals the sum of solute pressure and pressure potential. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Three components: The question is asking you to deduce the water potential and pressure potential for a given cell, given the solute potential. If you arrived at the correct answer, well done! If you came up with an incorrect answer, where did the process break down? Did you remember that water potential must equal the sum of pressure potential and solute potential? 56) Section Break 56.1) C 56.2) A 56.3) E 56.4) D 56.5) B
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Chapter 37 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) Plants that sequester heavy metals utilize pressure-flow where they move toxins from the source (soil) to a sink (such as the leaves). ⊚ ⊚
true false
2) A magnesium deficiency would impact the light-independent reactions but not the lightdependent reaction of photosynthesis. ⊚ ⊚
3)
A parasitic plant without chlorophyll is likely to lack leaves. ⊚ ⊚
4)
true false
true false
A plant with 80 available ATP could produce 10 molecules of NH3. ⊚ true ⊚ false
5) Blocking the proton pumps in a root would result in a more negative membrane potential and an increase in uptake. ⊚ ⊚
true false
6) <p>A soil sample with an aluminum. ⊚ true ⊚ false
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M may also have high levels of
1
7) As global temperatures increase, evidence suggests that ribulose 1, 5-biphosphate carboxylase/oxygenase (rubisco) is likely to denature and photosynthesis rates will decrease. ⊚ true ⊚ false
8)
Saline soils have a higher water potential than plant roots. ⊚ ⊚
9)
true false
Most parasitic plants like other land plants have mycorrhizal symbionts. ⊚ ⊚
true false
CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 10) When plants are grown in hydroponic culture, their roots are suspended in an aerated solution. Why is the solution aerated? Check all that apply. A) Both the light-dependent and the light-independent reactions of photosynthesis require oxygen. B) Oxygen is necessary for the root cells to produce ATP. C) Without oxygen, membrane transport in the roots would be impaired. D) A lack of oxygen would cause the water potential within the roots to decrease. E) Without oxygen, the xylem would stop flowing.
11) Humus often enhances the water and nutrient-retaining properties of topsoil. Which of the following might increase the humus content of a soil? Check all that apply.
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A) mushroom compost B) leaf litter C) ground limestone D) phosphate fertilizer E) fish meal
12) In the lab, you are studying the long-term effects of elevated carbon dioxide levels on photosynthesis in C3 and C4 plants. The C3 and C4 plants are growing in separate closed chambers. Both chambers are constantly given elevated but equal amounts of carbon dioxide. Which of the following are likely results of this experiment? Check all that apply. A) There would be a decrease in levels in both chambers. B) There would be an increase in levels in both containers. C) Both the C3 and the C4 plants would show equal gains in biomass. D) The C4 plants would gain more biomass relative to the C3 plants. E) The C3 plants would gain more biomass relative to the C4 plants.
13) Which of the following is a natural process of plants that can be used by humans to remove toxins from soils? Check all that apply. A) secretion of a substance from the roots that breaks down the toxic chemical B) "storage" of a toxic chemical in plant tissues, which are then removed from the site C) root pressure pushing toxins from deep in the soil towards the surface D) physiological breakdown of the chemical into harmless products E) transport of toxins absorbed by the roots into the shoots, where they can be collected more easily
14) Which of the following statements about plant macronutrients is/are true? Check all that apply.
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A) They approach or exceed 1% of a healthy plant's dry weight. B) They reduce the need for CO2 during photosynthesis. C) A deficiency in any one can have severe effects on a plant's growth. D) They can have important implications for human nutrition. E) The ability of the plants to take up minerals is affected by soil pH.
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 15) Plants can remove harmful chemicals from the soil by the process of A) glandular secretion by leaves. B) CO2 activation. C) phytoremediation. D) fertilization. E) root nodule formation.
16)
Trichloroethylene (TCE) is toxic to humans because it A) depletes nitrogen from soils. B) is carcinogenic. C) contains heavy metals. D) prevents CO2 production by plants. E) causes a decrease in the yield of crop plants.
17) Heavy metals in contaminated soils can be taken up by hyperaccumulating plants. Lead and cadmium taken up this way are often accumulated in the plants' A) rhizomes. B) trichomes. C) stomates. D) sclerenchyma. E) root nodules.
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18) Natural communities recycle nutrients, but cultivated communities often require an input of mineral nutrients due to losses through A) erosion. B) humus. C) nitrogen fixation. D) crop rotation. E) iron accumulation.
19) Carnivorous plants evolved because which of the following nutrients is often extremely limited in their habitats? A) carbon B) CO2 C) O2 D) nitrogen E) iron
20)
Which of the following statements about plants grown in hydroponic culture is true? A) They no longer need to transport water through their xylem. B) They cannot be used for commercial purposes. C) They rarely get enough micronutrients. D) They are unable to photosynthesize. E) They are suspended with their roots in a nutrient solution.
21) A primary advantage of using integrated nutrient management compared to inorganic chemical fertilizers is that
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A) less organic fertilizer is needed than chemical fertilizers. B) only organic fertilizers contain micronutrients. C) organic fertilizers release nutrients more slowly. D) chemical fertilizers are not soluble in water. E) chemical fertilizers break down very slowly.
22)
Certain plants have been genetically modified to secrete citrate, which helps A) make the phosphate in soils more soluble. B) plants make necessary micronutrients. C) reveal mineral deficiencies in a plant. D) make hydroponic growth possible. E) plants add metals to the soil in which they are growing.
23)
A deficiency in a plant micronutrient A) is less serious than a deficiency in a macronutrient. B) makes that plant susceptible to herbivores. C) can have a severe effect on plant growth. D) results in no visible symptoms. E) has no impact on the agriculture of a region.
24)
Inserting a cloned gene for a plasma membrane transporter into crop plants could lead to A) the ability of a plant to produce its own micronutrients. B) extra uptake of minerals that would fortify the crop for human consumption. C) the evolution of nodule-formation on the crop plant. D) elevated CO2 levels in the atmosphere. E) plants taking up enough minerals that they no longer need to photosynthesize.
25) A deficiency of ammonia would inhibit the production of which of the following molecules? Version 1
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A) proline and alanine B) starch C) short-chain fatty acids D) glucose and fructose E) long-chain fatty acids
26)
The Nod factor is an important component of A) the formation of the digestive enzymes of carnivorous plants. B) legume-bacterial interactions. C) mycorrhizal-terrestrial plant interactions. D) the Calvin Cycle. E) trichloroethylene metabolism.
27) Although symbiotic relationships between nitrogen-fixing bacteria and plants are rare, many plants have symbiotic relationships with A) other plants. B) nematode worms in the soil. C) filamentous algae. D) mycorrhizal fungi in the soil. E) soil insects.
28)
The effects of elevated atmospheric CO2 concentrations A) have the potential to alter the nutritional status of plants. B) have the potential to allow herbivores to eat less plant matter. C) have no effect on nutrient levels found in plant leaves. D) allow the plant to use O2 more efficiently in photosynthesis. E) cause an increase in rubisco production.
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29) in
Insectivorous plants such as the Venus flytrap, pitcher plant, and bladderworts often grow
A) alkaline soil. B) sandy soil. C) clay soil. D) marshes. E) acidic soils.
30) The habitats most favorable for the growth of legumes in symbiosis with nitrogen-fixing bacteria are A) potassium-poor soils. B) phosphorus-poor soils. C) manganese-poor soils. D) calcium-poor soils. E) nitrogen-poor soils.
31) Which of the following is most limiting for plant growth, especially in relation to the plant's carbon uptake? A) phosphorous B) potassium C) nitrogen D) calcium E) magnesium
32)
Which of the following is required by plants in the smallest quantity?
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A) boron B) potassium C) phosphorus D) nitrogen E) sulfur
33) During the initiation of nitrogen-fixation nodules, a host plant with genetic mutations releases altered forms of flavonoids. What is the likely consequence of this? A) Infection threads will grow in the wrong direction. B) More nodules will form than necessary. C) The bacteria will not produce any Nod factors. D) Nodules will be misshapen. E) The bacterial will produce higher levels of Nod factors.
34) During the initiation of nitrogen-fixation nodules, the Rhizobium bacteria release what type of molecules to signal the host plant? A) sugars B) proteins C) transcription factors D) flavonoids E) Nod factors
35) During the initiation of nitrogen-fixation nodules, how do the Rhizobium bacteria enter into the cortex of the root? A) through the plasmodesmata of the root hairs B) via the apoplastic pathway C) using proton pumps D) through a membrane tube called an infection thread E) by repeated cell divisions
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36)
Why do nitrogen-fixation nodules contain large amounts of leghemoglobin? A) It helps transport oxygen to the bacteria. B) The nitrogenase enzyme interacts with the iron in the leghemoglobin. C) The leghemoglobin helps break the triple bond of N2. D) It stimulates the Nod factors. E) It prevents carbon dioxide from inhibiting the nitrogenase enzyme.
37) When legumes with nitrogen-fixation nodules are given chemical fertilizers with high nitrogen concentrations, they abandon support of the nodules and end the symbiosis. Why? A) The mineral nutrients inhibit nitrogenase activity. B) Nitrogen gas is no longer available in the soil. C) The plant can conserve valuable energy sources by terminating the symbiotic relationship. D) The dissolved chemical nutrients are toxic to Rhizobium bacteria. E) Dissolved nitrogen uncurls the root hairs, releasing the nodule.
38)
Which of these insectivorous plants does not use an active trapping mechanism? A) pitcher plants B) Venus flytraps C) sundews D) the aquatic waterwheel E) bladderworts
39)
Mycorrhizae are especially effective in helping plant roots uptake
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A) nitrogen. B) phosphorus. C) potassium. D) iron. E) magnesium.
40) If increased CO2 concentrations result in plant tissue that is less nutritious, which of these is not a potential consequence for insect herbivores? A) They must eat more tissue. B) Their development may be slowed. C) They grow fatter because their diet has more carbohydrates. D) They use up more energy trying to eat for food. E) Their reproductive cycles may be disrupted because their rate of growth changes.
41) A plant cell with 64 available ATP molecules could split how many assistance of nitrogenase?
molecules with the
A) 2 B) 4 C) 16 D) 32 E) 64
42)
What makes a mineral element essential for plant growth? A) It is part of typical chemical fertilizers. B) It can only be found in organic fertilizers. C) If it is missing, the plant cannot grow or reproduce normally. D) As its concentration increases, the plant grows more. E) It contributes to the solute potential of the plant.
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43)
Why is it beneficial to plants that soil particles have negatively-charged surfaces?
A) It helps maintain the water potential of the soil. B) They attract positively-charged ions and prevent them from being washed deep into the soil. C) Negatively-charged ions are pushed towards the roots. D) Toxic metals are trapped and kept away from the plants. E) They capture negatively-charged ions.
44) In magnesium-deficient plants, the older leaves show more severe symptoms of chlorosis which is a yellowing of the leaves than younger leaves. What is the best explanation? A) There is more time for the symptoms to develop in older leaves. B) Chlorophyll is transported from the older leaves to the younger leaves. C) Magnesium is more soluble in younger leaves. D) Scarce magnesium is removed from older leaves and translocated to support younger, more active leaves. E) Older leaves need less chlorophyll.
45)
Inside nitrogen-fixing nodules, one N2 molecule is converted into two A) N. B) NO. C) NO2. D) NO3. E) NH3.
46) In several studies of plant responses to elevated CO2 concentrations in the atmosphere, scientists often found that the stimulation of growth gradually diminished because
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A) more photorespiration occurred. B) C3 plants were replaced with C4 plants. C) the soil did not contain sufficient nitrogen and other nutrients to support the enhanced growth. D) the plants could not store the extra biomass. E) weedy plants took over the experimental plots.
47)
Which of these is considered a potentially dangerous heavy metal contaminant in soil? A) cadmium B) iron C) copper D) molybdenum E) zinc
48) In acidic soils or in habitats subjected to prolonged acid rain, what element is often released from rocks that is toxic to many plants? A) iron B) chlorine C) molybdenum D) selenium E) aluminum
49) Researchers studying forests have found that trees interact with each other and with other organisms in the soils beneath the woods. Trees share resources with each other through their roots and through collaborations with mycorrhizal fungi. The term common mycorrhizal networks is sometimes used to describe this interacting network of roots and mycelium, but a catchier name often used is the “Wood Wide Web”. Which of the following types of interactions would NOT be enabled by the Wood Wide Web?
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A) The Wood Wide Web can be used to share the nitrogen fixed by mycorrhizae to trees that are growing in nutrient deficient soils. B) A tree suffering herbivory can use the Wood Wide Web to chemically communicate information about the presence of herbivores to other trees. C) Trees use the Wood Wide Web to compete with other species by spreading allelopathic chemicals further away from their trunks and roots. D) Trees with a surplus of phosphate can use the Wood Wide Web to share phosphates absorbed by the fungal mycelium with other trees with a deficit. E) An older, dying tree can use the Wood Wide Web to donate its remaining resources to younger trees in the forest.
SECTION BREAK. Answer all the part questions. 50) Choose the letter of the best match from the following: A. nitrogen B. calcium C. potassium D. phosphorus E. magnesium
50.1)
Contained in amino acids, proteins, nucleic acids, chlorophyll.
50.2)
Required for protein synthesis and operation of stomata.
50.3)
Component of cell walls, involved in maintenance of membrane structure.
50.4)
Component of chlorophyll, activates many enzymes, divalent cation.
50.5)
Component of ADP, ATP, nucleic acids, and several coenzymes.
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Answer Key Test name: Chap 37_13e_Raven 1) FALSE
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Clarify Question ● What is the key concept addressed by the question?● The question asks how a plant can move heavy metal from one tissue to another. ● What type of thinking is required?● You are being asked to take what you already know and apply it to the movement of a toxin from one location in a plant to another. ● What keywords does the question contain and what do they mean?● Pressure flow, which explains the movement of sugar within the phloem of a plant from source to sink. ● Source, which is a nutrient-producing structure such as a leaf. ● Sink, which is an area in a plant where nutrients are delivered and used. Gather Content ● What do you already know about heavy metals in plants? How does it relate to the question?● The phloem contains sugars that are made within the leaves of the plant. ● Phloem transports materials from the leaves to the stem and roots. ● Water enters the plant through the roots and is carried upward to other tissues via the xylem. ● Heavy metals may be present in the soil, so if they enter the plant, they would enter through the roots. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Phloem carries nutrients made within the plant, usually from leaves to other tissues.
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Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● To answer this question you need to connect the idea that the toxins are found in the soil with what you know about the transport system that moves water up from the roots. It is the xylem, not the phloem and pressure flow, that accomplishes this movement. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Apply level: ● This question asked you to apply what you know about transport within a plant. Answering this question correctly depended on your ability to use transport of material from the roots in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that the xylem moves material up from the roots, or that phloem moves material from source to sink? Did you have trouble extending how material moves upward in a plant to determine the correct answer? 2) FALSE
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Clarify Question ● What is the key concept addressed by the question?● The question is asking about the specifics of the importance of magnesium in photosynthesis. ● What type of thinking is required?● You are being asked to take what you already know and apply it to a magnesium deficiency during the stages of photosynthesis. ● What keywords does the question contain and what do they mean?● Magnesium, which is a macronutrient that is a component of chlorophyll. ● Light-dependent reactions, which capture sunlight and convert it into stored energy. ● Light-independent reactions, which used stored energy to fix CO2 into glucose. Gather Content ● What do you already know about the importance of magnesium in photosynthesis? How does it relate to the question?● Chlorophyll is a pigment that captures the majority of light energy that is used in photosynthesis. ● Magnesium is a necessary component of chlorophyll. ● In light-dependent reactions, chlorophyll captures light and stores the energy as ATP and NADPH. ● In light-independent reactions, the stored energy is used to fix CO2 into glucose. Consider Possibilities ● What other information is related to the question? Which Version 1
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information is most useful?● Without magnesium, chlorophyll cannot be synthesized. Without chlorophyll, the light-dependent reactions and consequently the light-independent reactions will not occur. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● To answer this question, you need to see the direct relationship between the presence of magnesium, the presence of chlorophyll, and the reactions of photosynthesis. If magnesium is removed, chlorophyll cannot be synthesized and photosynthesis cannot occur. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Apply level: ● This question asked you to predict what would happen to the reactions of photosynthesis if magnesium is not present. Answering this question correctly depended on your ability to use the role of magnesium in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that magnesium is required for chlorophyll structure, or that chlorophyll drives the light-dependent and in turn the light-independent reactions? Did you have trouble extending the function of magnesium to determine the correct answer? 3) TRUE
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the nature of a parasitic plant. ● What type of thinking is required?● You are being asked to take what you already know and apply it to how parasitic plants survive. ● What keywords does the question contain and what do they mean?● Parasitic, which involves one species that feeds off another. ● Chlorophyll, which is the chief light-absorbing pigment in photosynthesis. ● Leaves, which are structures in which photosynthesis occurs. Gather Content ● What do you already know about parasitic plants? How does it relate to the question?● Chlorophyll absorbs light energy, which drives the process of photosynthesis. ● Leaves are the primary site of photosynthesis. ● Parasitic plants obtain their energy from other organisms. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Since they lack chlorophyll, leaves would not be useful to the parasitic plant. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● To answer this question, the lack of chlorophyll must be correlated with a Version 1
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lack of photosynthesis. Since the plant is not photosynthetic, it would not need leaves. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Apply level: ● This question asked you to understand the nature of parasitic plants. Answering this question correctly depended on your ability to connect the concept of parasitic plants with the lack of need for leaves and chlorophyll. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that parasitic plants are not photosynthetic, or that the main function of leaves is photosynthesis? Did you have trouble extending the concept of parasitic plants to determine the correct answer? 4) TRUE
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the number of NH3 molecules that can be made with a designated amount of energy. ● What type of thinking is required?● You are being asked to take what you already know and apply it to the number of NH3 molecules that can be made with a given amount of energy. ● What key words does the question contain and what do they mean?● ATP, which is adenosine triphosphate, a usable form of cellular energy. ● NH3, which is ammonia, a molecule that is made from atmospheric nitrogen. Gather Content ● What do you already know about the energy required to produce NH3 molecules? How does it relate to the question?● 16 ATP molecules are required to split one N2 molecule. ● Splitting one N2 molecule would yield two nitrogen atoms, each of which could be converted into NH3. Consider Possibilities ● What other information is related to the question? Which information is most useful?● The relationship of 16 ATP to split one molecule N2 must be used to determine the number of NH3 that can be made with 80 ATP. Choose Answer Version 1
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● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Since 16 ATP molecules are required to split every N2, the number of N2 that can be split can be obtained by dividing the total number of ATP available, which is 80 ATP, by the number required to split one N2, which is 16 ATP. ● 80 divided by 16 equals 5. ● Each N2 molecule that is split yield two N atoms, each of which can be converted into NH3. ● 5 N2 molecules multiplied by 2 N atoms from each yields 10 N atoms, each of which can be built into a NH3 molecule. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Apply level: ● This question asked you to calculate the number of NH3 that can be made using 80 ATP molecules. Answering this question correctly depended on your ability to use the known amount of energy required to split N2 in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that 16 ATP are required to split every N2, and every N2 when split gives rise to two NH3? Did you have trouble extending this standard measure of energy to determine the correct answer? 5) FALSE
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the farreaching effects of proton pumps in the roots of a plant. ● What type of thinking is required?● You are being asked to take what you already know and apply it to the nature of proton pumps in a plant root. ● What keywords does the question contain and what do they mean?● Proton pump, which moves materials such as ions from one location to another. ● Membrane potential, which refers to a charge differential across a membrane.
Gather Content ● What do you already know about the effects of proton pumps in plant root cells? How does it relate to the question?● Proton pumps move H+ out of a plant. ● This makes it easier for the plant to move positively charged ions into the plant. ● Proton pumps move K+ into a plant.
Consider Possibilities ● What other information is related to the question? Which information is most useful?● If proton pumps were blocked, the H+ would not leave the plant. This additional positive charge would make it more difficult to move more positively charged ions in.
Choose Answer ● Given what you now know, what information and/or problem-solving approach is most likely to produce the correct answer?● Since proton pumps move ions in a way that promotes the entry of K+, if they were blocked, K+ would not enter the plant.
Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Apply level: ● This question asked you to connect the function of proton pumps with the entry of K+. Answering this question correctly depended on your ability to use the result of the action of proton pumps in a new situation. If you got the correct answer, great job! If you got an incorrect Version 1
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answer, where did the process break down? Did you remember that proton pumps move ions in such a way that K+ entry is facilitated? Did you have trouble extending the role of proton pumps to determine the correct answer?
6) TRUE Clarify Question ● What is the key concept addressed by the question?● This question is asking about the relationship between [OH-] and the aluminum content of the soil. ● What type of thinking is required?● You are being asked to take what you already know and apply it to a specific soil condition. ● What keywords does the question contain and what do they mean?● OH+ concentration, which can be used to calculate the pH of a substance. ● Aluminum, which is a metallic element that can be toxic to many plants. ●
7) FALSE Evidence suggest that enzymes like rusbico will experience an increase in activity for awhile and then acclimate to the temperature change. 8) FALSE
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about how water potential is affected by saline soil. ● What type of thinking is required?● You are being asked to take what you already know and apply it to the water potential of a new soil type. ● What key words does the question contain and what do they mean?● Saline, which refers to something that contains salt. ● Water potential, which is the relative proportion of water. Gather Content ● What do you already know about how water potential is affected by saline soil? How does it relate to the question?● As solute concentration increases, water potential decreases. ● Water flows from areas of higher water potential to areas of lower water potential. ● If roots have lower water potential than the soil, water flows into the roots. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Saline is a solute. Increased saline (solute) in the soil would not raise the water potential. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● In Version 1
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saline soil, the saline is a solute. This increased solute level would lower the water potential of the soil. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Apply level: ● This question asked you to relate salinity to water potential. Answering this question correctly depended on your ability to use the indirect relationship between solute concentration and water potential in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that saline is solute, or that increased solute lowers water potential? Did you have trouble extending concept the relationship between solute concentration and water potential to determine the correct answer? 9) FALSE
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the way parasitic plants obtain nutrients. ● What type of thinking is required?● You are being asked to take what you already know and apply it to the parasitic life style of some plants. ● What key words does the question contain and what do they mean?● Parasitic, which is the relationship by which one organism draws it nutrients from another. ● Mycorrhizae, which are fungi that aid plants the uptake of phosphorus. ● Symbionts, which are organisms that coexist. Gather Content ● What do you already know about how parasitic plants obtain nutrients? How does it relate to the question?● Parasitic plants do not undergo photosynthesis. ● Many parasitic plants lack roots and leaves. ● Parasitic plants obtain their nutrients from other organisms. ● Mycorrhizal fungi aid 90% of vascular plants with phosphorus and nutrient uptake. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Mycorrhizae would not benefit parasitic plants, as nutrients are obtained from host species. Choose Answer Version 1
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● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Since parasitic plants do not depend on nutrient uptake through the soil, an association with mycorrhizae would not be beneficial. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Apply level: ● This question asked you to understand nutrient uptake in parasitic plants. Answering this question correctly depended on your ability to recognize the role of mycorrhizal fungi in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that parasites do not undergo photosynthesis, and that do not take up nutrients from the soil? Did you have trouble extending concept the relationship between parasitism and nutrient uptake to determine the correct answer? 10) [B, C, E]
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the importance of oxygen at a molecular level in plants. ● What type of thinking is required?● You are being asked to take what you already know and apply it to an unknown situation involving the needs of plants grown using the hydroponic methodology. ● What keywords does the question contain and what do they mean?● Hydroponic, which is a method of growing plants in water instead of soil. ● Aerated, which means supplied with air. Gather Content ● What do you already know about the importance of oxygen in plants at the molecular plants? How does it relate to the question?● The cells of living things use oxygen to make ATP. ● In-plant roots, ATP is used to actively transport ions into the root. ● The movement of ions into the root lowers the water potential of the root. ● When water potential is lowered, water flows into the root where it can be carried further into the plant. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Oxygen is not required for photosynthesis. Choose Answer Version 1
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● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● To answer this question, you must recognize the importance of ATP in ion transport and subsequently of water flow into and through the plant. Without oxygen, ATP would not be synthesized and this transport would cease. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Apply level: ● This question asked you to understand the importance of oxygen in the physiology of plants. Answering this question correctly depended on your ability to use the importance of oxygen to plants in a new situation… If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that oxygen is necessary for ATP synthesis, or that ATP synthesis is necessary to drive ions and water into plants? Did you have trouble extending the need for oxygen and ATP to determine the correct answer? 11) [A, B, E]
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the nature of humus. ● What type of thinking is required?● You are being asked to take what you already know and apply it to the composition of humus. ● What key words does the question contain and what do they mean?● Humus, which is decaying organic material. ● Topsoil, which is a mixture of minerals, humus, and living things. Gather Content ● What do you already know about humus? How does it relate to the question?● Humus is a layer of material that is made of decaying organic material. ● Humus is a component of topsoil. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Limestone and phosphorus are inorganic. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● To answer this question, you have to realize that any material that was living contributes to humus. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Apply level: ● This question asked you to link materials to the formation of humus. Answering this question correctly depended on your ability to use the concept of humus in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that humus is composed of organic material or that inorganic material is classified differently? Did you have trouble extending the concept of humus to determine the correct answer? 12) [B, E]
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the effects of increasing on photosynthesis. ● What type of thinking is required?● You are being asked to take what you already know and apply it to an increase in in a sample. ● What keywords does the question contain and what do they mean?● Carbon dioxide, which is a molecule that is required for photosynthesis. ● C3, which refers to the most common type of plant. ● C4, which is a plant that cycles
into a 4-carbon product in photosynthesis.
Gather Content ● What do you already know about the effects of
on photosynthesis? How does it relate
to the question?● Photosynthesis uses and releases . ● C3 plants are more efficient in cool, wet climates. ● C4 plants are less efficient at photosynthesis, but avoid photorespiratory losses in tropical climates.
Consider Possibilities ● What other information is related to the question? Which information is most useful?● Since is released during photosynthesis, if photosynthesis increases, output would increase.
Choose Answer ● Given what you now know, what information and/or problem-solving approach is most likely to produce the correct answer?● To answer this question, you must connect the increase in with an increase in photosynthesis and release. You must also associate C4 plants with lower rates of photosynthesis when compared to C3 plants.
Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Apply level: Version 1
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● This question asked you to link increased to increased photosynthesis. Answering this question correctly depended on your ability to use the direct relationship between and photosynthesis in a new situation that also involves C3 and C4 metabolism. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that is a raw ingredient for photosynthesis, or that C3 plants are more efficient than C4 plants at photosynthesis? Did you have trouble extending concept the relationship between plant types and the role of in photosynthesis to determine the correct answer?
13) [A, B, D] 14) [A, C, D, E] 15) C Phytoremediation is the use of plants to concentrate or break down pollutants. 16) B TCE or trichoroethylene is a chemical that has many commercial uses. TCE is a confirmed carcinogen and prolonged exposure can damage the liver. 17) B Some plant species have evolved the ability to sequester heavy metals within their tissues. Many of these plants partition off these contaminants in the trichomes found on the surface of their leaves. 18) A Practices associated with cultivation such as plowing and harvesting disrupt the topsoil layer. This leads to erosion and the loss of the topsoil. 19) D Carnivorous plants are found in very acidic soils such as bogs that lack nitrogen. Consuming insects and other small organisms is an adaptation that evolved to obtain nitrogen. 20) E
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In hydroponic cultures, plants are grown with their roots suspended in aerated water containing nutrients. 21) C Organic fertilizers like animal manure release nutrients very slowly as they decompose. This reduces nutrient leaching and water pollution. 22) A Some plants have been genetically modified to secrete citrate. This is an organic acid that help make phosphate soluble. 23) C A deficiency in a micronutrient can have severe effects on plant growth. 24) B For many plants, the uptake of nutrients from the soil is limited by plasma membrane transport. Genes that code for these membrane transporters are being inserted into crop plants to make them more efficient at obtaining nutrients from the soil. 25) A
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Clarify Question ● What is the key concept addressed by the question?● The question is asking about the importance of ammonia to plants. ● What type of thinking is required?● You are being asked to take what you already know and apply it to the use of ammonia in plants. ● What keywords does the question contain and what do they mean?● Ammonia, which is an important source of nitrogen to plants. Gather Content ● What do you already know about ammonia in plants? How does it relate to the question?● Amino acids and proteins require nitrogen in their structure. ● Ammonia is an important source of nitrogen. ● Proline and alanine are amino acids. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Starch, glucose, and fructose are carbohydrates. ● Fatty acids and carbohydrates lack nitrogen in their structure. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● To answer this question, you must first realize that ammonia can be used as a nitrogen source in plants. You must then connect the fact that proline and alanine are amino acids with the fact that amino acids require Version 1
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ammonia. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level: ● This question asked you to identify proline and alanine as amino acids, and also to know that ammonia is a source of nitrogen. Answering this question correctly depended on your ability to use ammonia as a source of nitrogen in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that nitrogen can be obtained from ammonia, or that proline and alanine as amino acids require nitrogen? Did you have trouble extending ammonia as a nitrogen source to determine the correct answer? 26) B Nod factors are signals produced by rhizobia bacteria that induce a plant root hair to grow and curl around the bacteria. This is one of the stages in root nodule formation. 27) D About 90% of all vascular plants have a mutualistic symbiotic relationship with mycorrhizal fungi. The fungi help the plant to extract phosphorus in the soil in exchange for sugar. 28) A
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If the nitrogen availability does not increase along with the carbon dioxide, the tissues of the plant will be deficient in nitrogen and other macronutrients. This means that other organisms would need to eat more plant mass to obtain adequate nutrition. 29) E Acidic soils lack nitrogen. Consuming insects and other small animals supplies carnivorous plants with nitrogen. 30) E Rhizobium bacteria develop mutualistic symbiotic relationships with plants in nitrogen-poor soils. The bacteria fix nitrogen for the plants in exchange for carbohydrates and oxygen. 31) C Nitrogen availability limits plant growth. Nitrogen is a necessary component of proteins (including enzymes) , DNA and other molecules. As carbon dioxide levels rise, plant growth will still be limited by a lack of nitrogen in the soil since photosynthesis does not provide nitrogen to the plant. 32) A All the nutrients listed are macronutrients except boron. 33) C
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the effects of a mutation on the function of flavonoids in plants. ● What type of thinking is required?● You are being asked to take what you already know and apply it to a new situation in which flavonoids are altered. ● What keywords does the question contain and what do they mean?● Nitrogen fixation, which is the process by which unusable atmospheric nitrogen gas is converted into a usable form. ● Flavonoids, which are molecules that are produced in plant roots that signal bacteria to produce factors (Nod factors) that cause nodules to form around the bacteria. ● Nodule, which is a structure in a plant root that houses nitrogen-fixing bacteria. Gather Content ● What do you already know about flavonoids in plants? How does it relate to the question?● Flavonoids are produced by legume roots. ● Flavonoids are molecules that signal bacteria to produce Nod factors. ● Nod factors induce the formation of nodules. ● Nodules are the locations of nitrogen fixation in plants. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Without functional flavonoids, Nod factors will not be released, so no new nodules will not form.
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Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● To answer this question, you must connect flavonoids to the availability of Nod factors. If flavonoids are altered, Nod factors would be absent. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Apply level:● This question asked you to examine the role of flavonoids in Nod factor release. Answering this question correctly depended on your ability to use this role of flavonoids in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that flavonoids allow being released? Did you have trouble extending the function of flavonoids to determine the correct answer? 34) E Once the bacteria receive chemical signals called flavonoids from the plant root hair, they release chemical signals called Nod factors. This signals the root hair to grow and curl around the bacteria and the nodule begins to form. 35) D In the process of root nodule formation, the root hair grows and curls around the bacteria. The bacteria then initiate an infection thread which in an entryway for the bacteria into the root. 36) A Version 1
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Leghemoglobin is hemoglobin produced by the legume plant. It is similar to human hemoglobin in structure and function. It carries oxygen to the rapidly respiring aerobic bacteria in the root, but it controls its availability so that nitrogenase activity is not affected. 37) C
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Clarify Question ● What is the key concept addressed by the question?● This question addresses the benefit of nitrogen-fixation nodules. ● What type of thinking is required?● You are being asked to take what you already know and apply it to a situation in which the environment of a plant has changed. ● What keywords does the question contain and what do they mean?● Legume, which is a plant such as a bean or a pea that puts its seeds in a long case. ● Nitrogen-fixation nodule, which is a structure that contains nitrogenfixing bacteria. ● Symbiosis, which refers to two organisms that live together. Gather Content ● What do you already know about nitrogen-fixation nodules? How does it relate to the question?● Legumes form nodules when they are in nitrogen-poor soil. ● Nodules contain nitrogen-fixing bacteria that take unusable atmospheric nitrogen and convert it into a usable form. ● This helps to mitigate the nitrogen-poor environment. Consider Possibilities ● What other information is related to the question? Which information is most useful?● The only change is that nitrogen is more freely available. Since this has occurred, the plant no longer requires nitrogen-fixing bacteria. These bacteria are kept at a cost, which is the oxygen and carbohydrates that they require. By no longer supporting the nodules, the plant conserves resources. Version 1
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Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● To answer this question, you must connect the role of the nitrogen-fixing bacteria in the nodules with the nitrogen that they make available. Since nitrogen is newly added to the soil in the fertilizer and therefore readily available, the plant no longer needs the nodules. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Apply level: ● This question asked you to understand the main reason that it is beneficial to a plant to retain nodules. Answering this question correctly depended on your ability to use the function of these nodules in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that nodules function to make nitrogen available in nitrogen-poor soils, or that this would no longer be necessary if nitrogen is readily available? Did you have trouble extending the role of nodules to determine the correct answer? 38) A Pitcher plants curl their leaves into a pitcher-like shape. Inside the rim of the pitcher, they secrete a sugary solution. When insects and small animals try to feed off of the solution, they fall down to the bottom of the pitcher which is filled with water and digestive enzymes. 39) B Version 1
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Mycorrhizal fungi form a mutualistic symbiotic relationship with plants. In exchange for carbohydrates, the fungi transfer phosphate to the plant. 40) C As carbon dioxide levels rise there will be increase in photosynthesis but a decrease in the nutritional content of the plant tissues. 41) B
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the number of molecules that can be split with a designated amount of energy. ● What type of thinking is required?● You are being asked to take what you already know and apply it to the number of molecules that can be split with a given amount of energy. ● What keywords does the question contain and what do they mean?● ATP, which is adenosine triphosphate, is a usable form of cellular energy. ● , which is the form of nitrogen that exists as a gas in our atmosphere, but is unusable to plants in this form. ● Nitrogenase, which is an enzyme in the pathway that converts into .
Gather Content ● What do you already know about the energy required to split N2 molecules? How does it relate to the question?● The bond type that holds two nitrogen atoms together in a a triple covalent bond, which is very strong. ● 16 ATP molecules are required to split one N2 molecule.
molecule is
Consider Possibilities ● What other information is related to the question? Which information is most useful?● The relationship of 16 ATP to split one molecule must be used to determine the number of that can be split with 64 ATP.
Choose Answer ● Given what you now know, what information and/or problem-solving approach is most likely to produce the correct answer?● Since 16 ATP molecules are required to split every , the number of that can be split can be obtained by dividing the total number of ATP available, which is 64 ATP, by the number required to split one , which is 16 ATP. ● 64 divided by 16 equals 4.
Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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Apply level: ● This question asked you to calculate the number of that can be split using 64 ATP molecules. Answering this question correctly depended on your ability to use the known amount of energy required to split in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that 16 ATP is required to split every ? Did you have trouble extending this standard measure of energy to determine the correct answer?
42) C Essential nutrients are nutrients necessary for normal growth of the plant. 43) B Many of the nutrients that plants obtain from the soil are positively charged. These nutrients are attracted to the negative charges of the soil particles. This attraction keeps the nutrients from leaching deeper into the soil or washing away. 44) D
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Clarify Question ● What is the key concept addressed by the question?● Magnesium is an important component of chlorophyll. ● What type of thinking is required?● This question is asking you to weight and judge, or evaluate, the consequences of magnesium deficiency in plant tissue. ● What keywords does the question contain and what do they mean?● Magnesium, which is an essential macronutrient in plants that is a component of chlorophyll. ● Chlorosis, which is a condition that causes a yellowing of the leaves due to insufficient chlorophyll production. Gather Content ● What do you already know about the importance of magnesium in chlorophyll? How does it relate to the question?● Magnesium is a component of chlorophyll. ● Chlorophyll reflects green wavelengths of light, which gives plants their green color. ● Leaves that are deficient in chlorophyll turns yellow. Consider Possibilities ● What other information is related to the question? Which information is most useful?● The hydrocarbon tails of chlorophyll molecules attach to membranes in the chloroplast. ● The age of a leaf does not necessarily mean that it needs less chlorophyll. ● If a plant is magnesium deficient, at least initially leaves would be impacted equally. Version 1
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Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● To answer this question, you must connect the idea that chlorophyll synthesis requires magnesium with the effects of the removal of magnesium from plant tissues. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Evaluate level: ● This question asked you to explain a change in leaf coloration. Answering this question correctly depended on your ability to weigh and judge, or evaluate, the structure of the main plant pigment, chlorophyll, and the effects of the decline of chlorophyll in plant tissues. If you got the correct answer, well done! If you got an incorrect answer, where did the process break down? Did you remember that magnesium is a critical component of chlorophyll, or the criteria to compare old and new leaves include the synthesis of chlorophyll in new leaves? 45) E With the assistance of the enzyme nitrogenase, each N2 molecule is converted to two molecules of NH3. 46) C
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In these studies, plants exposed to elevated carbon dioxide showed an initial increase in photosynthesis and growth but this decreased over time. The limited availability of other nutrients like nitrogen prevented the continual increase in photosynthesis and growth. 47) A Cadmium is a metal that is toxic to animals in small quantities. Phytoremediation is a process used to help remove contaminants like cadmium from the soil. 48) E When soil pH is low, aluminum, which is toxic to plants, is released from rocks. 49) A
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Clarify Question ● What is the key concept addressed by the question?● Can you understand the role of mycorrhizae in networking plants? ● What type of thinking is required?● This question is asking you to weight and judge, or evaluate, statements about the role of mycorrhizae in sharing resources between plants Gather Content ● What do you already know about mycorrhizae? What other information is related to the question? ● Mycorrhizae play a significant role in enhancing phosphate transfer to associated plants. ● They do this by substantially extending the surface available for nutrient uptake. ● As noted in this question, trees can also share resources with each other through these networks of mycelia. ● Chemicals produced by one plant (whether signaling molecules for defense, allelopathic molecules to deter other plants or chemical resources stored in dying trees) can be shared through the mycelia. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● All of the resources could be shared among plants, but mycorrhizae do not themselves fix nitrogen for the plants. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to weight Version 1
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and judge, or evaluate, the possibility of sharing resources through the Wood Wide Web. If you got an incorrect answer, did you remember that any of the chemical compounds could be shared through mycelia, but that nitrogen is not fixed by mycelia itself? Did you have trouble weighing the merits of the choices because it required you to think about mycorrhizae in a different way to determine the correct answer? 50) Section Break 50.1) A Nitrogen is an important element in amino acids, nucleic acids and chlorophyll. 50.2) C Potassium plays an important role in protein synthesis and the operation of stomata. 50.3) B Calcium is an important component of cell walls and the maintenance of membrane structure and permeability. 50.4) E Magnesium is necessary for chlorophyll synthesis and it also activates many enzymes. 50.5) D Phosphorus is a necessary nutrient in the synthesis of ATP and ADP, nucleic acids, phospholipids and some coenzymes.
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Chapter 38 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) A nematode that has parasitized a plant root has breached the cutin layer of the epidermis. ⊚ ⊚
true false
2)
Treating a plant with a fungicide could interfere with the plant's uptake of nitrogen. ⊚ true ⊚ false
3)
Parasitic fungi will usually attack a plant through stomata on the root surface. ⊚ ⊚
true false
4) Systemic response occurs when plants exhibit generalized defense responses in organs distant from the wound. ⊚ ⊚
true false
5) Using biotechnology, plant breeders attempt to find and incorporate specific resistance genes into plants that lack them. Once a species of plant has been given a resistance gene, it will have indefinite protection from the associated pathogen. ⊚ ⊚
true false
6) If a bacterium containing a mutation in the avirulence gene lands on a plant that has the corresponding R gene, the bacterium may not initiate rapid cell death in the plant. ⊚ ⊚
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CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 7) Which of the following statements about the relationship between ants and acacia trees is/are accurate? Check all that apply. A) The ants protect the acacias from other insects. B) The ants protect the acacias from epiphytic plants and vines. C) The ants live in the hollow thorns of the acacias. D) The ants are provided with sugar or other nutrition by some species of acacia. E) The ants aid pollination of the acacias.
8)
Dermal tissue in plants A) is several cell layers thick. B) acts a barrier to potential pathogens. C) houses guard cells that defend against pathogen invasion. D) differs depending if it above ground or below ground.
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 9) _________blank occurs when a chemical signal secreted by the roots of one plant blocks the germination of nearby seeds or inhibits the growth of a neighboring plant. A) Nodulation B) Etiolation C) Reduction D) Allelopathy E) The systemic response
10)
Which of the following steps is not one of the phases of a fungal invasion of a plant?
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A) Windblown fungal spores land on plant leaves. B) Hyphae grow through cell walls and press against the cell membrane. C) Fungal DNA is replicated by the plant cells. D) Hyphae differentiate into specialized structures called haustoria. E) A fungal spore germinates and forms an adhesion pad that allows it to stick to a plant's leaf.
11) Nonnative plant invaders, such as the alfalfa plant bug, are extremely invasive and hard to control because A) they arrive in new locations where natural predators are not present. B) they tap into the xylem of a plant while seeking carbohydrates. C) they cause the plants' axillary buds to grow out. D) their populations evolve faster than the plants they attack. E) cause the plants' stomates to become unevenly distributed within the epidermis.
12) Which of the following methods do fungi use in order to penetrate the initial layer of a plant's defenses? A) mechanical bridging B) sharp mouthparts C) entry through stomates D) secretion of phospholipids to dissolve the cuticle
13)
Evidence that black walnut trees exhibit allelopathy includes A) the lack of vegetation growing under black walnut trees. B) the death of hornworms that try to eat black walnut leaves. C) the symbiotic relationship the trees have with fungi. D) the ants that protect the trees from herbivory. E) the morphological changes that occur in response to pathogenic attacks.
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14)
Tannins are chemicals that help plants repel invaders by A) over-stimulating the predator. B) sedating the predator. C) binding to proteins and thereby disrupting the predator's digestion. D) injuring the external covering of the predator's body. E) causing the predator to grow so rapidly that it dies.
15)
Which of the following statements about plant toxins against herbivores is false? A) The toxin may be kept in a membrane-bound structure to keep it from harming the
plant. B) The toxin may not be toxic unless it is metabolized in the intestine of a herbivore. C) The toxin may have also have a bad taste. D) Even a little bit of the toxin will be deadly. E) Some toxins can over stimulate particular physiological processes.
16)
Plants such as peppermint and sage contain oils. What is the function of these oils? A) They help keep the plant from drying out. B) They help repel insects. C) They keep other plants from germinating nearby. D) They prevent fungal infection. E) They have hormone-like activity that helps wounds heal.
17)
Which of the following plant secondary metabolites is used as an antimalarial drug?
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A) morphine B) taxol C) genistein D) quinine E) manihotoxin
18) Phytoestrogens are steroid-like chemicals that are derived from soy. One of their characteristics is that they are able to A) paralyze nerve endings. B) bind to the human estrogen receptor. C) cause estrogen breakdown within human cells. D) increase the rate of prostate cancer in men. E) cure malaria.
19)
Which of the following is a false statement about plant secondary metabolites? A) Some can be used to treat human diseases. B) Some can be poisonous to humans. C) The activity of certain medicines is due to secondary metabolites. D) Some of them can cross the placenta during pregnancy. E) They are too unpredictable to use in pharmaceutical research.
20) Parasitoid wasps are sometimes involved in a plant's defensive response. In what way are the wasps helpful to the plant? A) The wasps respond to a chemical the plant gives off when wounded, and the wasps lay their eggs on the caterpillar that wounded the plant. B) The wasps live in hollow thorns of the plants, and attack the plants' predators. C) The wasps stimulate the production of alkaloids the plants use for defense. D) The wasps enhance the plants' hypersensitive response. E) The wasps trigger leaf abscission so that herbivores do not have anything to eat.
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21)
Systemin can correctly be described as a(n) A) peptide. B) apoplast. C) receptor. D) leaf lipid. E) carbohydrate.
22)
How does systemin cause the activation of the wound response in tomato plants? A) It binds directly to jasmonic acid. B) It directly signals gene expression. C) It induces the production of tannins. D) It induces a jasmonic acid signaling pathway in certain cells. E) It triggers genes that are able to signal the plant that mechanical injury has occurred.
23) How does jasmonic acid contribute to the activation of the wound response in tomato plants? A) It moves through the phloem of the plant until it reaches the wound site. B) It produces a polypeptide that binds with membrane lipids. C) It binds to enzymes in the gut of the predator. D) It increases the energy available for the plants to fight the predator. E) It signals gene expression, leading to the production of a proteinase inhibitor.
24)
The activation of proteinase inhibitor genes occurs
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A) in the cytoplasm of the affected cells. B) on the plasma membrane of the affected cells. C) in the nucleus of the affected cells. D) before the systemin moves through the phloem of the plant. E) in anticipation of a physical wound to the plant.
25) is
The series of metabolic events that occurs within tomato plants in response to wounding
A) a systemic response. B) a waterfall effect. C) the hypersensitive response. D) a pathogen-specific response. E) resistance to coevolution.
26)
The steps in the pathogen-specific response do not include A) responding to the pathogen. B) development of antibodies. C) recognizing the pathogen. D) triggering the hypersensitive response. E) the pathogen releases distinctive proteins.
27)
Which of the following statements about the pathogen-specific response is true?
A) The pathways involved always trigger the hypersensitive response. B) The pathogen is recognized by its avr gene product. C) There is never a gene-for-gene response. D) If the R gene product is not triggered, no disease will occur. E) Avr and R gene pairs have been cloned in species pathogenized by microbes, fungi, and insects.
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28) Viruses travel through animals mainly by lysing cells and then spreading to other cells. Plant cells are not easily lysed. If a pathogen enters a plant cell and does not initiate a hypersensitive response, what is the most likely way the virus would spread to other plant cells? A) Through the chloroplasts B) Directly through the cell wall C) Through the central vacuole D) Through the plasmodesmata E) Through transport vesicles
29)
Systemic acquired resistance is A) a broad-ranging resistance that lasts for a period of days. B) the same as the human immune response. C) a response whereby antibodies recognize specific antigens. D) a response that occurs when the hypersensitive response fails. E) a method for plants to modify their DNA for protection.
30)
Which of the following chemicals is a signal that induces systemic acquired resistance? A) salicylic acid B) brassinosteroids C) systemin D) avr E) nitric acid
31) Cyanogenic glycosides, which break down into cyanide, are toxic to cells because they inhibit the function of which organelle(s)?
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A) Golgi apparatus B) Ribosome C) Nucleolus D) Mitochondria E) Endoplasmic reticulum
32) What is the main difference between plant defense mechanisms that use secondary chemical metabolites versus plant defense mechanisms that use a systemic response? A) The metabolites are not as lethal as the systemic response. B) The metabolites are present at all times, and the systemic response must be induced. C) The metabolites can only help in defense against insects, not against other plants. D) The metabolites are toxic to the plants that produce them, the systemic response is safer. E) The metabolites are a more reliable way to kill the invader.
33) The plant alkaloid ricin is nontoxic inside castor beans, but becomes active when digested by an animal. The toxic form of ricin kills by A) inactivating the animal's immune system. B) over stimulating the animal's heart rate. C) inactivating ribosomes needed for translation. D) binding to RNA polymerase. E) releasing cyanide.
34) Taxol, a secondary metabolite from the bark of the Pacific yew tree, is used as a treatment for
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A) diabetes. B) breast cancer. C) indigestion. D) headaches. E) high blood pressure.
35) Which category of plant second metabolites includes stimulants like caffeine, nicotine, and cocaine? A) tannins B) alkaloids C) phenolics D) cyanogenic glycosides E) terpenes
36) Which common crop may contain traces of hormone-like substances that may affect human health? A) corn B) wheat C) peanuts D) soybean E) wine grapes
37)
What plant secondary metabolite was isolated from the Cinchona tree to fight malaria? A) digitalis B) penicillin C) acacia D) taxol E) quinine
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38) Why don't ants that protect the Acacia tree scare off bees trying to pollinate the tree's flowers? A) They can't climb to the tops of the tree. B) The bees are too big. C) The bees fly in and out quickly. D) The open flowers contain a chemical that is an ant deterrent. E) Parasitoid wasps protect the bees from attack.
39) In your garden, you have anAilanthus altissima, also known as the Tree-of-Heaven. You try adding additional plants to the same garden bed but notice poor seed germination and seedling growth around the tree. What is the most likely explanation for this? A) The tree is blocking most of the available sunlight which is limiting germination and growth. B) The tree is utilizing most of the available micronutrients in the soil. C) The roots of the tree have a stronger water potential than the seedlings which is causing the seedlings to dehydrate. D) The tree has a mutualistic relationship with animals that are removing plants that are in competition for resources with the tree. E) The tree is releasing chemicals into the soil that are inhibiting germination and growth of other plants.
40) Many plants are filled with toxins that kill or deter herbivores. Many plants sequester these compounds within the cell. Where in the plant cell are these toxic substances most likely stored? A) Central vacuole B) Mitochondria C) The stroma D) Amyloplasts E) Lysosomes
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41) A patient who requires repeated dosing with strong analgesics over a period of more than a few days might be prescribed which of the following secondary plant metabolites? A) Genistein B) Morphine C) Quinine D) Taxol E) Cyanogenic glycosides
42) A plant has a mutation in the gene that codes for systemin. What is the likely consequence of this mutation? A) The plant will have a stronger than normal wound response. B) The mutated form of systemin would be recognized as a pathogen and a hypersensitive response will be initiated. C) The levels of jasmonic acid will build inside the cell creating a toxic environment. D) Systemin receptors will not be activated and proteinase inhibitor will not be transcribed. E) R genes will fail to match up with avr genes.
43) While the relationship between plant roots and mycorrhizal fungus is a mutualistic one, it is also true that the fungus must invade the root tissue, which is in fact an infection that can promote a defensive response. Researchers have found that this mycorrhizal-induced resistance primes the plant for future interactions with pathogens, inducing a more efficient response of jasmonic acid signaling pathways to subsequent attacks on the plant. What does this suggest about mycorrhizal-induced resistance? A) Plants with mycorrhizal associations will have amplified wound responses. B) Plants with mycorrhizal associations are more likely to recruit parasitoid wasps. C) Plants with mycorrhizal associations are more prone to hypersensitive responses. D) Plants with mycorrhizal associations have a higher number of avr genes. E) Plants with mycorrhizal associations have a higher number ofR genes.
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44) Cotesia congregata is a parasitoid wasp that attacks more than a dozen species of caterpillars including the tomato hornworm, Manduca sexta. Recent research has indicated that C. congregata is more likely to attack hornworms on wild tomatoes over domesticated tomato plants. Which of the following would explain this different behavior? A) The domesticated tomato plants release different volatile compounds in response to herbivory than the wild tomato plants. B) The domesticated tomato plants have fewer R genes than the wild tomato plants. C) The domesticated tomato plants have fewer avr gene products than the wild tomato plants. D) The domesticated tomato plants release less salicylic acid than the wild tomato plants. E) The domesticated tomato plants produce less jasmonic acid than the wild tomato plants.
45) TheHM1 gene in maize controls expression of the HCTR (NADPH-dependent HC toxin reductase), which inactivates HC toxin, a cyclic tetrapeptide that is produced by the fungusCochliobolus carbonum to enable it to infect a plant. Which of the following terms describes HCTR? A) R gene product B) avr gene product C) salicylic acid D) jasmonic acid E) systemin
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Answer Key Test name: Chap 38_13e_Raven 1) FALSE
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the nature of a nematode infection in terms of plant tissue. ● What type of thinking is required?● You are being asked to take what you already know and apply-it to effects of a parasitic infection to a plant. ● What key words does the question contain and what do they mean?● Nematode, which refers to a large group of animals that include roundworms. ● Cutin, which is a waxy compound that is found in plant tissues. ● Epidermis, which is the outer tissue of a plant. Gather Content ● What do you already know about how nematodes infect plants? How does it relate to the question?● Suberin covers the epidermis of the root. ● Nematode parasites attack the roots of a plant. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Cutin is found in plant tissues that occur above ground level. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Since nematodes attack plant roots, and cutin is not associated with plant root structure, cutin would not be breached with a nematode attack.
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level: ● This question asked you to assess the effects of a nematode invasion on plant tissue. Answering this question correctly depended on your ability to use your knowledge of plant tissues in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that cutin is associated with structures that grow above ground level, or that nematodes attack the roots of plants? Did you have trouble extending your knowledge of plant tissues to determine the correct answer? 2) FALSE
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Clarify Question ● What is the key concept addressed by the question?● The question is asking about the role of fungi in plant life. ● What type of thinking is required?● You are being asked to take what you already know and apply it to assess the importance of fungi to plants. ● What keywords does the question contain and what do they mean?● Fungicide, which is a substance that kills fungi. ● Nitrogen, which is an element that is an essential part of substances such as amino acids and proteins. Gather Content ● What do you already know about the relationship between plants and fungi? How does it relate to the question?● Mycorrhizal fungi form mutualistic associations with plants. ● Plants provide the fungi with carbohydrates, while the fungi enhance the phosphorus uptake by plants. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Bacteria from mutualistic associations with plants in that they change nitrogen into a form that is usable by plants. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Since it is bacteria, not fungi, that fix nitrogen for plants, killing the fungi around a plant would not affect nitrogen uptake.
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level: ● This question asked you to understand the role of fungi in plant life. Answering this question correctly depended on your ability to use the relationship between fungi and plants in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that fungi aid phosphorus uptake by plants, or that bacteria aid nitrogen uptake? Did you have trouble extending the role of fungi to determine the correct answer? 3) FALSE
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about how parasitic fungi enter a plant. ● What type of thinking is required?● You are being asked to take what you already know and apply it to how parasitic fungi enter plant hosts. ● What keywords does the question contain and what do they mean?● Parasitic, which is an organism that feeds off another organism. ● Stomata, which are small openings on the surface of a plant. Gather Content ● What do you already know about how parasitic fungi interact with plants? How does it relate to the question?● Parasitic fungi do enter their host plants through stomata. ● Stomata occur on the leaves of plants. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Stomata do not occur on the roots of plants. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Although parasitic fungi do enter a host plant through stomata, this occurs on the leaves of plants. Roots do not possess stomata. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result?● Apply level: ● This question asked you to assess the route of entry for parasitic fungi into a plant host. Answering this question correctly depended on your ability to use the pathway for parasitic fungi in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that parasitic fungi enter a plant through the stomata and that stomata occur on the leaves of a plant? Did you have trouble extending the mode of entry to determine the correct answer? 4) TRUE Systemic means that the response occurs throughout the body of the organism. 5) FALSE
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the longevity of the effect of a resistance gene that has been inserted. ● What type of thinking is required?● This question is asking you to evaluate the consequences of the insertion of a resistance gene into a plant. ● What keywords does the question contain and what do they mean?● Biotechnology, which uses cellular processes to enhance new products. ● Resistance gene, which is a gene that gives plant protection against disease. ● The pathogen, which is a disease-causing agent. Gather Content ● What do you already know about gene insertion and genetic variation? How does it relate to the question?● Proteins are constructed from recipes specified in the DNA of an organism. ● DNA is subject to change via mutation. ● Resistance genes produce R proteins. ● R proteins interact with avirulence (avr) proteins in pathogens, signaling the presence of the pathogen in the plant’s defense system. Consider Possibilities ● What other information is related to the question? Which information is most useful?● If the avr gene mutates, the protein will change. ● If the avr protein changes, the R protein will not recognize it. ● If recognition does not occur, the defense pathway will not take place. ● Without the defense pathway, the plant is vulnerable to the pathogen. Version 1
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Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● As long as genes and gene products such as the avr protein can change, as is always possible through mutation, it is possible that recognition will not occur between the R protein and the avr protein. If this recognition does not occur, the defense pathway does not occur and the plant is not protected from the pathogen. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Evaluate level: ● This question asked you to evaluate how long protection against a pathogen can last. Answering this question correctly depended on your ability to evaluate the possibility of genetic change. If you got the correct answer, well done! If you got an incorrect answer, where did the process break down? Did you remember that recognition is based on the structure of the R protein and the avr protein, or the criteria to compare genetic change can cause a change in the shape of a protein? Did you have trouble weighing the merits of genetic change and a corresponding change in protein shape to determine the correct answer? 6) TRUE
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the extent of the effect of a mutation in an avr gene. ● What type of thinking is required?● This question is asking you to evaluate the consequences of a mutation in an avr gene in a bacterium. ● What keywords does the question contain and what do they mean?● Resistance gene, which is a gene that gives plant protection against disease. ● avr gene, which is a gene that aids in the recognition of a pathogen. Gather Content ● What do you already know about avirulence and R genes? How does it relate to the question?● Proteins are constructed from recipes specified in the DNA of an organism. ● DNA is subject to change via mutation. ● Resistance genes produce R proteins. ● R proteins interact with avirulence (avr) proteins in pathogens, signaling the presence of the pathogen in the plant’s defense system. ● Once a pathogen is recognized, rapid cell death may occur in the plant to prevent the spread of the pathogen. Consider Possibilities ● What other information is related to the question? Which information is most useful?● If the avr gene mutates, the protein will change. ● If the avr protein changes, the R protein will not recognize it. ● If recognition does not occur, the defense pathway will not take place. ● Without the defense pathway, the plant is vulnerable to the pathogen. Choose Answer Version 1
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● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● As long as genes and gene products such as the avr protein can change, as is always possible through mutation, it is possible that recognition will not occur between the R protein and the avr protein. If this recognition does not occur, the defense pathway does not occur and the plant is not protected from the pathogen. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Evaluate level: ● This question asked you to evaluate the effects of mutation in a gene involved in pathogen recognition. Answering this question correctly depended on your ability to evaluate the possibility of genetic change. If you got the correct answer, well done! If you got an incorrect answer, where did the process break down? Did you remember that recognition is based on the structure of the R protein and the avr protein, or the criteria to compare genetic change can cause a change in the shape of a protein? Did you have trouble weighing the merits of genetic change and a corresponding change in protein shape to determine the correct answer? 7) [A, B, C, D] Acacia trees are actually pollinated by bees. 8) [B, D]
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Dermal tissue is one cell thick although it may have multiple layers of wax on the surface. The above ground portion is covered by the waxy substance called cutin while the below ground portions are covered by a different waxy substane called suberin. The epidermis functions to protect the plant from pathogens, UV radiation and water loss. The epidermis contains pores (stomata) that are regulated by guard cells. These guard cells regulate gas exchange and do not have a role in pathogen defense. 9) D Alleleopathy occurs when a chemical compound secreted by the roots of one plant blocks the germination of nearby seeds or inhibits the growth of neighboring plants. 10) C 11) A Species that are nonnative did not evolve in a particular ecosystem. Therefore, they may lack natural predators. 12) C 13) A The lack of vegetation under the tree would indicate that the plant is releasing chemicals that poison other plants. 14) C Tannins bind to proteins, such as digestive enzymes, and inactivate them. 15) D Toxicity varies among the secondary metabolites. 16) B
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Plant oils evolved to repel insects with their strong odor. They may also be toxic in large quantities. 17) D Quinine is a secondary metabolite used as an antimalarial drug. 18) B Genistein, a phytoestrogen produced by soybeans, is an estrogen mimic. 19) E Many secondary metabolites are used in the pharmaceutical industry. 20) A Some plants release a volatile compound when injured by a catepillar. This chemical is attracts parasitoid wasps. A wasp will lay her eggs in the body of the catepillar and when the eggs hatch, the larvae kill and consume the catepillar. 21) A Systemin is an 18-amino-acid peptide that when bound to a receptor initiates the release of jasmonic acid. This chemical then activates the production of a proteinase inhibitors which bind to the digestive enzymes of an herbivore. 22) D Systemin activates jasmonic acid which in turn activates a defense response. 23) E Jasmonic acids leads to the transcription of defensive genes. 24) C Genes, which are segments of DNA, are located in the nucleus. 25) A Version 1
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A systemic response refers to a response to injury that is spread throughout, system-wide, of the body of the organism. For example, wounding a tomato leaf leads to the production of jasmonic acid in other parts of the plant. 26) B The pathogen-specific response occurs when a pathogen enters a plant cell and resleases proteins. If the plant has an R gene that matches one of these proteins, it will bind to it initiating a hypersensitivity response. Antibodies are found in animals. 27) B A hypersensitive response in a plant will be initiated if an R gene (from the plant) binds to an avr gene (from the pathogen). This response is called the "gene for gene hypothesis." 28) D
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Clarify Question ● What is the key concept addressed by the question?● This question asks you to identify how a virus can exit a plant cell. ● What type of thinking is required?● You are being asked to take what you already know and apply it to how a virus can work within plant tissue. ● What key words does the question contain and what do they mean?● Virus, which is a submicroscopic, potentially infectious parasite. ● Lysed, which is the rupture of a cell membrane when viruses break out of a cell. ● Pathogen, which is a disease-causing agent. Gather Content ● What do you already know about how plant viruses spread between cells? How does it relate to the question?● Plant cells have a cell wall outside of the cell membrane. ● The cell wall of a plant cell provides support for the cell. ● Plasmodesmata are small channels that allow plant cells to interact with their environment. ● The hypersensitive response seals off a wounded or infected area by causing cell death. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Chloroplasts and the central vacuole occur within a cell, and would not provide a pathway out of the cell. ● The cell wall is composed of cellulose, and does not allow for the free Version 1
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flow of materials by itself. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● To spread to other cells, viruses need a pathway through the cell wall. The plasmodesmata are such a pathway. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level: ● This question asked you to determine how a virus can exit a plant cell. Answering this question correctly depended on your ability to use plant cell structure in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that plant cells differ from animal cells in that plant cells have cell walls, or that plasmodesmata allow materials to move in and out of plant cells? Did you have trouble extending plant cell structure to determine the correct answer? 29) A 30) A Salicylic acid is the chemical that induces the SAR response. 31) D
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Clarify Question ● What is the key concept addressed by the question?● This question is asking you to identify the organelles that are affected by cyanide. ● What type of thinking is required?● You are being asked to take what you already know and apply it to the effects of cyanide to plant cells. ● What keywords does the question contain and what do they mean?● Cyanogenic, which refers to a chemical that gives rise to cyanide. ● Cyanide, which is a toxin that inhibits the electron transport chain in cellular respiration. ● Organelle, which is a subcellular structure with a specific function. Gather Content ● What do you already know about cyanide toxicity? How does it relate to the question?● The electron transport chain occurs in the mitochondria in plant cells. Consider Possibilities ● What other information is related to the question? Which information is most useful?● While the Golgi, ER, ribosomes, and nucleoli are sites of specialized function, they do not play a direct role in the electron transport chain or in cellular respiration. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● The mitochondria are the only organelles involved in cellular respiration. If cellular respiration is inhibited, mitochondrial activity will also be inhibited. Version 1
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level: ● This question asked you to determine the impact of cyanide on plant cells. Answering this question correctly depended on your ability to use the effect of cyanide in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that cyanide inhibits the electron transport chain, or that the electron transport chain occurs in the mitochondria of plant cells? Did you have trouble extending the effect of cyanide to determine the correct answer? 32) B Plants stockpile secondary metabolites, so they are constantly present within the plant tissues. A systemic response only occurs after being invaded by a pathogen. 33) C 34) B Many secondary metabolites have medicinal value. 35) B Caffeine, nicotine and cocaine are alkaloids which effect multiple cellular processes in animals. 36) D Soybeans produce phytoestrogens which may have medicinal value to humans. 37) E Version 1
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38) D The flowers of the acacia tree produce a chemical compound that repels the ants. This allows bees to pollinate the flowers without being harmed by the ants. 39) E
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Clarify Question ● What is the key concept addressed by the question?● This question is asking you to identify the reason that plants are not growing around a Tree-of-Heaven. ● What type of thinking is required?● This question is asking you to evaluate the reason for the lack of germination and growth in plants that occur around a Tree-of-Heaven. ● What keywords does the question contain and what do they mean?● Tree-of-Heaven, which is one of the names for the deciduous tree with the scientific name Ailanthus altissima. ● Germination, which is the process of plant growth from a seed. Gather Content ● What do you already know about plant interactions? How does it relate to the question?● Certain plants put allelopathic chemicals into the soil, which inhibits the growth of other plants around them. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Other trees have plants that grow around them, even if sunlight is blocked. ● It is not likely that a tree would usurp so many of the micronutrients in the soil that other plants would be inhibited in both germination and growth. ● The question describes inhibited growth, not the removal of plants by animals, which would look very different. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● The Version 1
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inhibition of both germination and growth is very suggestive of a chemical agent at work in the soil that would inhibit both of these processes. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Evaluate level: ● This question asked you to explain why plants are inhibited around the Tree-of-Heaven. Answering this question correctly depended on your ability to evaluate the normal growth of one plant and relate it with the lack thereof in nearby plants. If you got the correct answer, well done! If you got an incorrect answer, where did the process break down? Did you remember that allelopathy causes the very effects of inhibition that are described in the problem? 40) A
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Clarify Question ● What is the key concept addressed by the question?● This question is asking where toxins are stored in plants. ● What type of thinking is required?● You are being asked to take what you already know and apply it to the understanding of where plants store toxins. ● What keywords does the question contain and what do they mean?● Herbivore, which refers to an organism that eats plants. ● The sequester, which means to store. Gather Content ● What do you already know about plant toxin sequestration? How does it relate to the question?● Plants can store toxins in membranebound structures. ● The central vacuole of a plant is membrane-bound. ● The central vacuole of a plant cell is a storage area for many different molecules. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Amyloplasts store starch. ● The stroma is not a membrane-bound organelle. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Toxins are stored in membrane-bound structures with plant cells. The membrane-bound structure that is known for macromolecule storage is the central vacuole.
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level: ● This question asked you to identify the location in which toxins are stored. Answering this question correctly depended on your ability to use your knowledge of plant cell structure and function in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that the central vacuole is an area in which molecules are stored, or that toxins are stored in membrane-bound structures? Did you have trouble extending your knowledge of plant cell structure to determine the correct answer? 41) B
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the secondary plant metabolite that can be used as a pain reliever. ● What type of thinking is required?● You are being asked to take what you already know and apply it to the use of secondary plant metabolites for human pain relief. ● What key words does the question contain and what do they mean?● Analgesic, which is a substance that relieves pain. ● Secondary plant metabolite, which is a substance that is made by a plant, but is not necessary for the survival of the plant. Gather Content ● What do you already know about a secondary plant metabolite that can be used as a pain reliever? How does it relate to the question?● Morphine is a secondary plant metabolite. ● Morphine has pain-relieving properties. Consider Possibilities ● What other information is related to the question? Which information is most useful?● Cyanogenic glycosides give rise to cyanide. ● Taxol has anticancer properties. ● Quinine is an anti-malarial agent. ● Genistein is an estrogen mimic. Choose Answer ● Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?● Morphine is the only choice that has pain-relieving properties. Version 1
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level: ● This question asked you to assess which secondary plant metabolite can relieve pain. Answering this question correctly depended on your ability to use the characteristic of plant secondary metabolites in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that morphine relieves pain, or that morphine is a secondary plant metabolite? Did you have trouble extending the properties of secondary plant metabolites to determine the correct answer? 42) D
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Clarify Question ● What is the key concept addressed by the question?● The question is asking what will occur if systemin is absent. ● What type of thinking is required?● This question is asking you to evaluate the function of systemin. ● What keywords does the question contain and what do they mean?● Mutation, which is a mistake or a misreading of the genetic code. ● Systemin, which is a protein in plants. Gather Content ● What do you already know about the function of systemin? How does it relate to the question?● Mutations can cause proteins to be nonfunctional. ● Systemin is a protein involved in defense response in plants. ● When systemin is present, it triggers the production of jasmonic acid. ● Jasmonic acid facilitates the defense response. ● Proteinase inhibitor is a protein used in the defense response. Consider Possibilities ● What other information is related to the question? Which information is most useful?● A mutation would likely cause the systemin to go unrecognized. ● Without systemin, jasmonic acid would not be produced. ● R genes and avr genes are involved in pathogen recognition and response. Choose Answer ● Given what you now know, what information and/or problemsolving approach is most likely to produce the correct answer?● Removing systemin, as would happen with a mutation, would stop the Version 1
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defense response pathway. If this pathway is inhibited, proteinase inhibitors would not be produced. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Evaluate level: ● This question asked you to evaluate the effect of the loss of systemin. Answering this question correctly depended on your ability to evaluate what would occur if systemin is removed from the plant. If you got the correct answer, well done! If you got an incorrect answer, where did the process break down? Did you remember that systemin is necessary for the defense response, or the that production of proteinase inhibitor is an end result of the defense pathway? Did you have trouble weighing the merits of the presence of systemin in the defense pathway to determine the correct answer? 43) A
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Clarify Question ● What is the key concept addressed by the question? ● Can you differentiate between plant systemic responses? ● What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to identify a plant defensive response. Gather Content ● What do you already know about plant defense responses? What other information is related to the question? ● Some plants respond to wounding by caterpillars by releasing a volatile compound to attract parasitoid wasps. ● In a wound response, plants respond to wounding by releasing systemin. Systemin moves through the apoplast to trigger the production of jasmonic acid in cells, leading off a pathway that ends in the production of proteinase inhibitors. ● In a gene-for-gene response, plants respond to the presence of a specific pathogen when an R gene product produced by the plant binds to an avr gene product produced by the pathogen. ● This can lead to a hypersensitive response, leading to rapid cell death in the cells around the wound, sealing off the pathogen. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer? ● Given the mycorrhizal-induced resistance leads to more efficient response of jasmonic acid signaling pathways, these plants will have amplified wound responses. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use knowledge of plant defense responses in a new situation. If you got an incorrect answer, did you remember that jasmonic acid is associated with a wound response, or that gene-for-gene responses lead to a hypersensitive response? Did you have trouble extending the wound response to mycorrhiza to determine the correct answer? 44) A
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Clarify Question ● What is the key concept addressed by the question? ● Can you identify the way plants interact with parasitoid wasps? ● What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to determine why a parasitoid wasp favors wild tomatoes. Gather Content ● What do you already know about the relationship between plants and parasitoid wasps? What other information is related to the question? ● A female parasitoid wasp lays her fertilized eggs in the body of a caterpillar. When the eggs hatch, the emerging larvae kill and eat the caterpillar. ● Some plants respond to wounding by a caterpillar by releasing a volatile compound that attracts parasitoid wasps. ● R genes and avr genes are associated with a gene-for-gene response that recognizes pathogens and often leads to a hypersensitive response to stop the spread of the pathogen. ● Jasmonic acid is important in the production of proteinase inhibitors as part of the wound response. ● Salicylic acid is a signaling molecule important for systemic acquired resistance. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer? ● Since the question is asking about the recruitment of parasitoid wasps, the answer cannot be any of the compounds that are retained within the tomato plant. Volatile compounds produced in response to caterpillar herbivory are the chemicals used to attract parasitoid wasps. Version 1
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Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use knowledge of plant defense responses in a new situation. If you got an incorrect answer, did you remember that parasitoid wasps are attracted by volatile compounds, or that jasmonic acid and salicylic acid are compounds used for signaling in plant systemic responses? Did you have trouble extending your knowledge of parasitoid wasps to determine the correct answer? 45) A
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Clarify Question ● What is the key concept addressed by the question? ● Can you identify components of plant defense responses? ● What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to identify a plant defensive response. Gather Content ● What do you already know about plant defense responses? What other information is related to the question? ● In a gene-for-gene response, an R gene produces an R gene product (such as a protein) in a plant, while the avr gene produces an avr gene product by a pathogen. When both are present, the R gene product binds to the avr gene product, initiating a hypersensitive response preventing continued infection. ● Systemin is a signaling molecule important for wound response. Binding of systemin triggers production of jasmonic acid, which is important in the production of proteinase inhibitors as part of the wound response. ● Salicylic acid is a signaling molecule important for systemic acquired resistance. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer? ● This question is referring to HCTR, a product of the HM1 gene, inactivating a specific compound produced by a pathogen. This is an example of a gene-for-gene response. HM1 is an R gene, and HCTR is an R gene product. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use knowledge of plant defense responses in a new situation. If you got an incorrect answer, did you remember that R and avr gene products are part of the gene-for-gene response, or that R gene products produced by plants identify specific pathogenic avr gene products? Did you have trouble extending the gene-for-gene response given the unfamiliar terminology to determine the correct answer?
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Chapter 39 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) While researching the effects of light on chlorophyll synthesis in sorghum, you find that brief pulses of red light stimulates the synthesis of chlorophylla andb. This would suggest that chlorophyll synthesis is directed by the Pr form of phytochrome. ⊚ ⊚
2)
true false
The removal of the root cap eliminates the ability of a root to respond to gravity. ⊚ ⊚
true false
CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 3) Chemical inhibitors of hormone synthesis or signaling are powerful tools that yield invaluable information about hormone function. Triadimefon, propiconazole, and spironolactone are just a few of the compounds identified to inhibit the function of brassinosteroids (BR). Which of the following are probable physiological effects due to the inhibition of BR? Check all that apply. A) reduced mitotic activity B) rapid aging C) reduced xylem and phloem differentiation D) increased stem length
4) Red light and phytochrome are involved in which of the following plant growth responses? Check all that apply. A) thigmotropic responses B) inhibition of seed germination C) elongation of etiolated shoots D) detection of crowding by neighboring plants
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5)
Which of the following are true statements about gibberellins? Check all that apply. A) They can restore normal growth and development in certain dwarf mutants. B) They inhibit amylase and other hydrolytic enzymes. C) They are produced in the apical regions of shoots and roots. D) They promote internode elongation. E) They hasten seed germination.
6) Which of the following describe a role that ethylene plays in plant physiology. Check all that apply. A) Retarding stem and root elongation B) Hastening the ripening of fruit C) Inhibition of lateral bud growth D) Inhibition of leaf abscission E) Accelerates the loss of damaged fruits
7)
Which of the following statements about abscisic acid are true? Check all that apply. A) It stimulates the growth of dormant buds. B) It is produced chiefly in mature green leaves and in fruits. C) It promotes leaf senescence. D) It plays an important role in controlling the opening and closing of stomata. E) It plays a role in seed dormancy.
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 8) If temperatures suddenly rise 5 to 10º C,_________blank proteins are produced to help stabilize other proteins.
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A) denatured B) photosensitive C) chilling D) heat shock E) oxidative
9) Rapid turgor pressure changes in specialized multicellular swellings called_________blank are associated with leaves that move in response to touch or light. A) petioles B) pulvini C) stipules D) pudicas E) coleoptiles
10) Mature plants may become_________blank in dry or cold seasons in order to survive long periods that are unfavorable for growth. A) dormant B) dehydrated C) photoperiodic D) thigmonastic E) gravitropic
11) _________blank are chemical substances produced in small quantities in one part of an organism and then transported to another part of the organism, where they bring about physiological responses.
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A) Glycoproteins B) Photosynthates C) Hormones D) Heat shock proteins E) Pulvini
12) Gibberellins affect many processes in plants. In seeds embryos, gibberellins are believed to signal hydrolysis of the stored food reserves through inducing the synthesis of the enzyme αamylase. Which food source are gibberellins targeting with the release of α-amylase? A) omega-3 fatty acids B) starch C) glycogen D) fructose E) protein
13) A plant sustains pathogen-induced damage to one of its cell walls. A gene-for-gene response soon follows and the tissue surrounding the injury soon dies. Which signaling molecules facilitated this response? A) Oligosaccharins B) Ethylene C) Gibberellins D) Auxins E) Abscisic acid
14) _________blank is directional growth responses of plants to a unidirectional source of light.
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A) Gravitropism B) Thigmotropism C) Dormancy D) Phototropism E) Thermotropism
15)
Charles Darwin and his son experimented with which plant growth response? A) gravitropism B) circadian rhythms C) phototropism D) heat shock E) thermotropism
16) The plant hormones known as_________blank may have an evolutionary origin in the common ancestor to both plants and animals. A) brassinosteroids B) oligosaccharides C) cytokinins D) auxins E) abscisic acids
17)
Which cell structure is most likely responsible for sensing gravity? A) central vacuole B) Golgi appartus C) chloroplast D) amyloplast E) apical meristem
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18) While touring a farm, the farmer tells you that she uses cytokinin to increase crop productivity. But, from biology class you know that cytokinin alone has no effect on parenchyma cells. What other substance is the farmer most likely using in conjunction with cytokinin? A) auxin B) abscisic acid C) strigolactones D) ethylene E) suberin
19) While touring the ancient Egypt exhibit at the local history museum, you learn that ancient Egyptians would slash figs in order to stimulate ripening. Based on your knowledge of plant hormones you hypothesize that wounding the figs must release A) abscisic acid. B) gibberellin. C) indoleacetic acid. D) ethylene. E) cytokinin.
20) Abscisic acid (ABA) is synthesized in the roots in response to decreased soil water potential. ABA then translocates to the leaves, where it rapidly alters the osmotic potential of guard cells. What effect would this have on the stomata and the process of transpiration? A) The stomata would open thereby increasing the rate of transpiration. B) The stomata would open thereby decreasing the rate of transpiration. C) The stomata would close thereby decreasing the rate of transpiration. D) The stomata would close thereby increasing the rate of transpiration. E) The change in the stomata would have no effect on the rate of transpiration.
21)
The elongation of stems is stimulated by
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A) auxin only. B) gibberellin only. C) ethylene only. D) auxin and gibberellin. E) auxin and ethylene.
22) When Darwin covered the tip of a grass seedling with metal foil and then illuminated it from one side, what happened to the seedling? A) It bent away from the directional light. B) It did not respond to the directional light. C) It grew toward the light, as expected. D) It waved back and forth. E) It wilted and died.
23) One effect of auxin, which triggers the elongation of cells, is to affect cell walls by increasing their A) permeability. B) plasticity. C) stiffness. D) thickness. E) water solubility.
24) When seeds are removed from strawberries, fruit growth is stopped. This suggests the seeds contain which of the following hormones? A) ethylene B) auxin C) strigolactones D) oligosaccharides E) gibberellins
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25)
A compound similar to auxin, 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), has been used A) as a fertilizer for corn and wheat. B) as a spray to promote flowering of pineapple. C) as an organic substitute for chlorine bleach. D) to detoxify the dangerous poison dioxin. E) an herbicide for killing woody seedlings and dicot weeds.
26) Climbing plants, such as vines, rely on touch to navigate and develop tendrils that coil around objects they encounter. Roots also rely on touch to navigate their way through the soil. When roots come into contact with an object, they generally grow in a direction away from the object. Based on this information, which of the following statements is true? A) Both tendrils and roots are displaying thigmonastic responses to an object in the environment. B) The tendrils are displaying a thigmonastic response while the roots are displaying a thigmotropic response. C) The tendrils are displaying a positive thigmotropic response while the roots are displaying a negative thigmotropic response. D) The tendrils are displaying a thigmotropic response while the roots are displaying a thigmonastic response. E) The tendrils are displaying a negative thigmotropic response while the roots are displaying a positive thigmotropic response.
27) Coconut milk was an extremely useful additive in plant tissue culture because, in addition to amino acids, it contains A) auxins. B) gibberellins. C) cytokinins. D) ethylene. E) abscisic acid.
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28) While flipping through an agriculture products catalog, you come across the following advertisment, "The Centralized Ripening System—makes large scale hormone distribution even easier!". What hormone does this product distribute? A) auxin B) abscisic acid C) cytokinin D) ethylene E) gibberellin
29) Which naturally-occurring plant hormone has a major role in the phototropic response of plants? A) auxin B) gibberellin C) abscisic acid D) ethylene E) 2, 4-D
30)
The directional growth response of plants to touch is called A) phototropism. B) gravitropism. C) thigmotropism. D) photoperiodism. E) thermotropism.
31) What endogenous process helps plants to keep their movements and other responses synchronized with the environment?
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A) purine monitoring B) solar tracking C) a circadian clock D) auxin cycling E) gravitropism
32)
The acid growth hypothesis links A) oligosaccharins to pH changes. B) cytokinin to thigmonasty. C) auxin to cell wall expansion. D) gibberellin to root elongation. E) ethylene to leaf abscission.
33) During a viticulturist's presentation on growing and managing grapes, why did he state that it is imperative to encourage the grapevine's natural tendency for positive thigmotropism? A) To encourage the vine's response to move toward the early morning light as opposed to the late afternoon sun B) To encourage the roots to grow deeper and spread out C) To encourage the grapes to retain their sugar for a longer period of time D) To encourage the twining stems to wrap around the supporting wires E) To discourage early ripening of the fruit
34) Several scientists, including Charles and Francis Darwin, Frits Went and others, demonstrated that auxins caused stems to bend toward light in a series of elaborate experiments. Went was the researcher who finally determined that bending of the stem toward light was a result of which mechanism?
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A) Light caused a reduction in auxin concentration and a reduction in stem elongation on the lighted side of the plant stem, and thus a bending in the direction of the light. B) The transport of auxin to the shaded side of the plant stem stimulated stem elongation and a bending in the direction of the light. C) Auxin concentration was equal on both sides (lighted and shaded) of the stem; however, the apical meristem responded to the presence of light. D) A combination of positive phototropism and a negative gravitropism. E) The stems actually were responding to the agar blocks that had been used in the experiments.
35) A scientist is investigating a hormone response in rose bush stems by removing the apical meristems of the main stems. What is the most likely result of this experiment and what hormone is responsible? A) New apical buds will develop under the influence of auxin. B) Larger, deeper roots will form under the influence of cytokinin. C) More leaf buds will appear along the main stems under the influence of auxin. D) Flowers will turn yellow and fall off under the influence of auxin. E) Lateral buds will develop under the influence of cytokinin.
36) A viticulturist wants to grow larger grapes. Which specific hormone would a viticulturist apply to the plants? A) auxin B) cytokinin C) gibberellin D) abscisic acid E) ethylene
37) A plant physiologist treats a leaf with abscisic acid and observes that the stomata close. What happened inside the guard cells during the experiment?
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A) Abscisic acid influences the movement of sodium ions out of the guard cells. B) Abscisic acid influences the movement of potassium ions out of the guard cells. C) Abscisic acid binds carbon dioxide and causes carbonate crystals to block the stomatal opening. D) Abscisic acid binds with auxins and induces water molecules to exit the guard cells. E) Abscisic acid causes the guard cells to become more turgid.
38)
Directional, light-triggered plant development is known as A) thigmotropism. B) phototropism. C) thigmonasty. D) photomorphogenesis. E) acid-growth movement.
39) What happens when coleoptiles are illuminated with directional light from the side instead of from directly overhead? A) More auxin is produced. B) Less auxin is produced. C) Auxin is transported away from the lighted side. D) Auxin is transported toward the lighted side. E) Auxin receptors are activated.
40) Before ARF transcription factors can trigger auxin-induced gene expression, what must happen? A) Auxin binds to ubiquitin, a degradation tag. B) Auxin degrades Aux/IAA proteins which repress ARF transcription factors. C) Auxin binds to TIR1, an auxin receptor. D) Auxin must bind to the ARF transcription factor. E) Ubiquitin must destroy TIR1 to release Aux/IAA proteins.
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41) In some genetically engineered tomatoes, fruit ripening was delayed by crippling the gene that produces which hormone? A) auxin B) ethylene C) abscisic acid D) gibberellin E) cytokinin
42) When one plant is shaded by another, why is the ratio of far-red to red light increased compared to an unshaded plant? A) Phytochrome in the taller plant absorbs most of the red light. B) Auxin absorbs mostly far-red light. C) As light passes through the leaves of the taller plant, most of the red light is absorbed by chlorophyll. D) Far-red light mostly reflects off the surface of the soil while red light is mostly absorbed. E) Shade is enriched in far-red wavelengths of light.
43) In Arabidopsis plants, about 7% of its genome is devoted to processes tied to which molecule? A) auxin B) ubiquitin C) rubisco D) phytochrome E) gibberellins
44)
How do nastic movements differ from tropisms?
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A) Nastic movements are slower than tropisms. B) Nastic movements only occur in the dark. C) Tropisms are directional responses to directional stimuli; nastic movements are the same regardless of the direction of the stimulus. D) Nastic movements happen after a stimulus, tropisms happen during a stimulus. E) Nastic movements are not reversible.
45) Abscisic acid synthesized in the root travels to different parts of the shoot where it regulates transpirational water loss. What is the most likely way that ABA travels from the root to the various locations within the shoot? A) vessels and tracheids B) sieve tubes C) between cell walls D) from cell to cell through the plasmodesmata
46) Plants maintain higher levels of phytochrome at their growing tips where phytochrome plays important roles in growth responses to light. Phytochrome levels are also high in areas of the plant that are "greening". What does this suggest about the role of phytochrome in these "greening" zones? A) Phytochrome is absorbing green wavelengths of light. B) In these areas, phytochrome is the first step in the electron transport chain of photosynthesis. C) Phytochrome is facilitating the transcription and translation of photosynthesis related proteins. D) Phytochrome is facilitating the migration of chlorophyll pigments from other areas of the plant.
47) Why do plants growing outside often have shorter and thicker stems than plants of the same species grown indoors?
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A) The plants inside have a more constant source of light and therefore a higher level of phytochrome. B) The outdoor plants are subject to mechanical stresses and they are exhibiting a thigmomorphogenic response. C) The outdoor plants are subject to touch by animals and other plants and are exhibiting a thigmotropic response. D) The indoor plants have elevated levels of auxin and are therefore taller than the outside plants.
48) Research has shown that cytokinin levels fluctuate seasonally in temperate plants. What season would you expect to see the lowest levels of cytokinins and why would this be adaptive? A) Spring, because lower levels of cytokinin allow auxin to promote rapid growth in stem height. This will allow the plant to compete effectively for sunlight. B) Summer, because lower levels of cytokinin would slow growth down and delay leaf aging. This will allow the plant to maximize the production of starch and increase it's sugar reserves. This will help ensure the plant's survival through Autumn and Winter. C) Autumn, because lower levels of cytokinin at this time of year will induce the production of ethylene. This will result in maturation of fruit and ensure effective seed dispersal before Winter. D) Winter, because lower levels of cytokinin will place buds into a dormant state. This will protect the underlying tissues from freezing until Spring.
49)
Which part of a root tip is responsible for perceiving gravity? A) root cap B) zone of cell division C) zone of elongation D) zone of maturation
50)
Which of the following about seed dormancy isnot true?
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A) Seed dormancy is common in tropical climates. B) High levels of abscisic acid trigger seed dormancy. C) Annual plants frequently utilize seed dormancy to wait until after the dry season has ended before germinating. D) Embryos inside of some seeds can germinate after hundreds of years.
51)
How do heat shock proteins protect plants from high temperatures?
A) Heat shock proteins stabilize other proetins so that they don't denature at higher temperatures. B) Heat shock proteins prevent carbohydrates from being hydrolized at higher temperatures. C) Heat shock proteins prevent the double helix of DNA molecules from unwinding at higher temperatures. D) Heat shock proteins prevent lipids from dissolving at higher temperatures.
52) Thelazy gene was named because plants with mutations to it tend to have shoots and roots that grow horizontally. Sometimes their roots even grow upward and emerge from the soil rather than growing downward. Further research indicates thatlazy gene products normally cause asymmetrical distribution of auxin in both shoots and roots, whereas mutation oflazy alters the auxin transport in the shoot and reverses auxin asymmetry in the root tip.Based on this description, what process is likely regulated by the lazy gene? A) Gravitropism B) Phototropism C) Photomorphogenesis D) Thigmotropism E) Thigmonastic response
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SECTION BREAK. Answer all the part questions. 53) Choose the letter of the best match from the following: A. abscisic acid B. auxin C. ethylene D. cytokinin E. gibberellin
53.1)
A chemical derivative of adenine.
53.2) Its defoliant effects were first noticed when it leaked from gas lights; later found to be produced by plants themselves.
53.3)
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17
Answer Key Test name: Chap 39_13e_Raven 1) FALSE
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Clarify Question • What is the key concept addressed by the question? o The question is asking about the different forms of phytochrome. • What type of thinking is required? o This question is asking you to evaluate-phytochrome use in a plant. • What key words does the question contain and what do they mean? o Chlorophyll, which is a pigment that absorbs light that can be used in photosynthesis. o Red light, which includes wavelengths of light that are used in photosynthesis. o Phytochrome, which is a pigment-containing protein. Gather Content • What do you already know about "phytochromes and photosynthesis? How does it relate to the question? o Active processes require the conversion of Pr to Pfr. Consider Possibilities • What other information is related to the question? Which information is most useful? o Since chlorophyll synthesis requires active phytochrome, the Pr would need to become Pfr. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o In the presence of red light, the Pr form of phytochrome is converted to the active form Pfr which would direct the synthesis of chlorophyll. Version 1
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: This question asked you to evaluate the different forms of phytochrome. Answering this question correctly depended on your ability to evaluate when Pr and Pfr act. If you got the correct answer, well done! If you got an incorrect answer, where did the process break down? Did you remember that Pr differs from Pfr in that Pfr is required for active processes? Did you have trouble weighing the merits of Pr relative to Pfr to determine the correct answer? 2) TRUE
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Clarify Question • What is the key concept addressed by the question? o This question is asking about the importance of the root cap. • What type of thinking is required? o You are being asked to take what you already know and apply it to the function of a root cap. • What key words does the question contain and what do they mean? o Root cap, which is the covering that occurs at the end of a root. Gather Content • What do you already know about root caps? How does it relate to the question? o The gravity-sensing cells of the root are located in the root cap. o Studies have shown that removing the cap eliminates the root's ability to respond to gravity. Consider Possibilities • What other information is related to the question? Which information is most useful? o Since gravity-sensing cells are located in the root cap, removal of the root cap would eliminate this ability. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o To answer this question you must connect the presence of gravitysensing cells with the root cap. Removal of the root cap would remove gravity-sensing cells from the root. Version 1
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o This question asked you to understand the nature of the root cap. Answering this question correctly depended on your ability to use the composition of the root cap in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that the root cap contains gravitysensing cells? Did you have trouble extending the nature of the root cap to determine the correct answer? 3) [A, B, C]
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Clarify Question • What is the key concept addressed by the question? o This question is asking about the function of brassinosteroids. • What type of thinking is required? o You are being asked to take what you already know and apply it to the loss of a plant hormone. • What key words does the question contain and what do they mean? o Brassinosteroids, which are a class of plant hormones. o Inhibition, which refers to restricting a process. o Physiological, which refers to processes that occur in living things. Gather Content • What do you already know about brassinosteroids? How does it relate to the question? o Brassinosteroids are responsible for a broad spectrum of physiological responses in plants. Consider Possibilities • What other information is related to the question? Which information is most useful? o Brassinosteroids function in stem elongation, so inhibition of these hormones would not lengthen the stem. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Inhibiting brassinosteroids would disrupt elongation, cell division, vascular tissue (xylem and phloem) tissue development and speed up Version 1
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aging in plant. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o This question asked you to assess the importance of brassinosteroids. Answering this question correctly depended on your ability to use the functions of brassinosteroids in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that brassinosteroids promote stem elongation and other processes? Did you have trouble extending the function of brassinosteroids to determine the correct answer? 4) [B, C, D] Phytochrome is involved in all the responses except thigmotropi. Thigmotropic responses are a response to a physical stimulus. 5) [A, C, D, E] 6) [A, B, C, E] 7) [B, C, D, E] 8) D If temperatures suddenly rise, heat shock proteins are transcribed. These proteins help prevent the denaturation of other proteins. 9) B Pulvini are two-sided multicellular swellings located at the base of leaves or leaflets in many plants. 10) A 11) C Version 1
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12) B
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Clarify Question • What is the key concept addressed by the question? o This question is asking about the function of amylase. • What type of thinking is required? o You are being asked to take what you already know and apply it to the use of amylase. • What key words does the question contain and what do they mean? o Gibberellin, which is a plant hormone. o Hydrolysis, which refers to the splitting of larger molecules into smaller molecules. o Amylase, which an enzyme that occurs in plants. Gather Content • What do you already know about hormone and enzyme function in plants? How does it relate to the question? o Gibberellins have multiple roles within plants. o Amylase, is an enzyme that breaks down starch into individual glucose molecules. Consider Possibilities • What other information is related to the question? Which information is most useful? o Amyl/o- is a word root that refers to starch, not other macromolecules. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The key in this question is the reference to amylase. Amylase is an Version 1
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enzyme that is found in plants and other organisms, and it is used to break down starch. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o This question asked you to understand the role of amylase. Answering this question correctly depended on your ability to use the function of amylase in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that amyl/o is always a reference to starch, or that amylase is an enzyme that hydrolyzes starch? Did you have trouble extending the function of amylase to determine the correct answer? 13) A
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Clarify Question • What is the key concept addressed by the question? o The question is asking about the signaling molecules that initiate response to injury in plants. • What type of thinking is required? o You are being asked to take what you already know and apply it to the response of a plant to tissue damage. • What key words does the question contain and what do they mean? o Pathogen-induced, which means a disease-causing agent is responsible. o Gene-for-gene, which is a response that aids pathogen recognition. o Signaling molecules, which carry chemical message to tissues. Gather Content • What do you already know about injury response in plants? How does it relate to the question? o Oligosaccharins are found in cell walls. o The hypersensitive response is a gene-for-gene response that causes tissue death in the area surrounding the injury. o Tissue death inhibits the ability of the pathogen to spread. Consider Possibilities • What other information is related to the question? Which information is most useful? o Ethylene promotes fruit ripening and leaf, flower, and fruit abscission. o Gibberellin promotes stem elongation and production of enzymes in germinating seeds. o Auxin has many functions, but is not involved in the hypersensitive response. Version 1
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o Abscisic acid inhibits bud growth, plays a role in seed dormancy, inhibits other hormones, and controls stomatal closure. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The other chemicals mentioned do not play a direct role in signaling that results in a hypersensitive response. When a cell wall is damaged by a pathogen, evidence suggests that oligosaccharins are released and a hypersensitive response occurs. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o This question asked you to assess the hypersensitive response in a plant. Answering this question correctly depended on your ability to use the mechanics of this response in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that oligosaccharins are found in cell walls, and that they are released when the cell wall is damaged? Did you have trouble extending the presence of these molecules to determine the correct answer? 14) D 15) C 16) A
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The similarity between brassinosteroids are structurally similar to animal steroid hormones. This suggests and evolutionary origin the predates the animal-plant split. 17) D Amyloplasts are the structures believed to be responsible for sensing gravity. 18) A Cytokinin is a hormone that works in conjunction with auxin to stimulate cell division and differentiation. 19) D
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Clarify Question • What is the key concept addressed by the question? o The question is asking about chemical influences on fruit ripening. • What type of thinking is required? o You are being asked to take what you already know and apply it to the ripening of fruit. • What key words does the question contain and what do they mean? o Ripening, which is a maturation process by which fruit become sweeter and softer. Gather Content • What do you already know about fruit ripening? How does it relate to the question? o Hormones drive processes in plants, including ripening of fruit. Consider Possibilities • What other information is related to the question? Which information is most useful? o Gibberellin promotes stem elongation and production of enzymes in germinating seeds. o Auxin has many functions, but is not involved in fruit ripining. o Abscisic acid inhibits bud growth, plays a role in seed dormancy, inhibits other hormones, and controls stomatal closure. o Cytokinin promotes cell division. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o Ethylene is the only hormone listed that promotes fruit ripening. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o This question asked you to assess fruit ripening. Answering this question correctly depended on your ability to use the characteristics of plant hormones in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that ripening is hormone-driven, or that ethylene promotes ripening? Did you have trouble extending the characteristics of plant hormones to determine the correct answer? 20) C
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Clarify Question • What is the key concept addressed by the question? o The question is asking about the role of stomata in transpiration. • What type of thinking is required? o This is an analyze question because you have to break the stomata and transpiration into their component pieces to understand how they function. • What key words does the question contain and what do they mean? o Stomata, which are openings on leaves. o Guard cells, which regulate the stomata. o Transpiration, which is the evaporation of water from plant leaves. Gather Content • What do you already know about the relationship between transpiration and stomata? How does it relate to the question? o Abscisic acid (ABA) plays an important role in the opening and closing of the stomata. o Stomata regulate water loss from the leaves. Consider Possibilities • What other information is related to the question? Which information is most useful? o Decreased water flow into the plant would not cause the stomata to open. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o Decreased soil water potential would result in a reduced water flow into the plant. o To prevent dehydration, ABA would signal the guard cells to close. o Closed guard cells would reduce transpiration and prevent dehydration. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o This question asked you to understand the factors that regulate transpiration. Answering this question correctly depended not only on distinguishing between the roles of different hormones, but on your ability to break down, or analyze, the effects of hormones on the stomata and transpiration. If you got the correct answer, excellent! If you got an incorrect answer, where did the process break down? Did you remember that ABA influences stomatal activity, or that stomata regulate transpiration? Did you have trouble breaking down the functions of the hormones to determine the correct answer? 21) D Both auxin and gibberllins enhance plant growth. 22) B Charles Darwin and his son Francis, found that when a shoot tip was covered with foil, the shoot would not bend. This finding eventually led to the discovery of auxin. 23) B Auxin has many roles in a plant, two of which are to increase the plasticity (flexibility) of plant cell walls and stimulate stem elongation. Version 1
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24) B
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Clarify Question • What is the key concept addressed by the question? o The question is asking about the effect of seed removal from a fruit. • What type of thinking is required? o You are being asked to take what you already know and apply it to the importance of seeds to fruit. • What key words does the question contain and what do they mean? o Seeds, which are plant embryos. o Fruit, which is a seed-bearing structure produced by a plant. o Hormones, which are chemicals that can regulate processes in tissues. Gather Content • What do you already know about the relationship between seeds and fruit? How does it relate to the question? o A strawberry lacking seeds will not develop. o If treated with a synthetic auxin, the fruit will grow. Consider Possibilities • What other information is related to the question? Which information is most useful? o Ethylene is involved with ripening. o Gibberellins influence seed germination. o Strigolactones and oligosaccharides do not appear to have a role in fruit formation. Choose Answer • Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer? o Auxin is involved with the formation of fruit. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o This question asked you to understand the importance of seeds to fruit. Answering this question correctly depended on your ability to use the characteristics of seeds in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that seeds contain hormones that influence fruit, or that auxin is a hormone that stimulates fruit formation? Did you have trouble extending the characteristics of seeds to determine the correct answer? 25) E 26) C
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Clarify Question • What is the key concept addressed by the question? o This question is asking you to assess the type of growth responses exhibited by a climbing plant. • What type of thinking is required? o This question is asking you to evaluate the type of growth responses shown by a climbing plant. • What key words does the question contain and what do they mean? o Tendrils, which is a coiling, thin extension of a plant. o Climbing plant, which is a plant with a relatively weak stem that uses other structures for support. Gather Content • What do you already know about plant responses to their environments? How does it relate to the question? o In a thigmonastic response the direction of the growth is the same regardless of the direction of the stimulus. o Thigmotrophic growth occurs directionally. Consider Possibilities • What other information is related to the question? Which information is most useful? o Neither the tendrils or the roots are displaying a thigmonastic response. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o Both the tendrils and roots are thigmotrophic. Growth toward the stimulus would be positively thigmotropic. Growth away from the stimulus would be negatively thigmotropic. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: This question asked you to evaluate the growth of the roots and stems of a plant. Answering this question correctly depended on your ability to evaluate the specific growth patterns of the stem and roots. If you got the correct answer, well done! If you got an incorrect answer, where did the process break down? Did you remember that thigmotrophic growth occurs in a certain direction, or the criteria to compare positive versus negative thigmotrophism includes analysis of whether growth occurs toward or away from a stimulus? Did you have trouble weighing the merits of the growth patterns to determine the correct answer? 27) C Coconut milk contains cytokinins which work with auxin to stimulate cell division and differentiation. 28) D
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Clarify Question • What is the key concept addressed by the question? o This question is asking about the use of chemicals to speed up fruit ripening. • What type of thinking is required? o You are being asked to take what you already know and apply it to the ripening of fruit. • What key words does the question contain and what do they mean? o Ripening, which means the maturation of fruit. Gather Content • What do you already know about fruit ripening? How does it relate to the question? o Hormones regulate the activities of plant tissues. o Ripening is regulated by hormones. Consider Possibilities • What other information is related to the question? Which information is most useful? o Auxin has many functions, but is not involved in ripening. o Abscisic acid inhibits bud growth, plays a role in seed dormancy, inhibits other hormones, and controls stomatal closure. o Cytokinin promotes cell division. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Ethylene is a hormone that facilitates ripening in fruit.. Version 1
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o This question asked you to assess fruit ripening. Answering this question correctly depended on your ability to use the role of hormones in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that ripening requires hormones, or that ethylene ripens fruit? Did you have trouble extending the functions of hormones to determine the correct answer? 29) A 30) C 31) C Circadian rhythms relate the day-night cycle to the eukaryotic organism that has them. 32) C The acid growth hypothesis provides a model linking auxin to cell wall expansion. 33) D
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Clarify Question • What is the key concept addressed by the question? o This question is asking about the importance of thigmotropism. • What type of thinking is required? o This question is asking you to evaluate the use of thigmotropism in grapes. • What key words does the question contain and what do they mean? o Viticulturist, which refers to one who grows grapes. o Grapevine, which is a climbing plant o Thigmotropism, which is directional growth in response to encountering an object. Gather Content • What do you already know about plant growth and thigmotropism? How does it relate to the question? o Grapevines exhbit positive thigmotropism. o Positive thigmotropism is the directional growth of a plant towards a stimulus. Consider Possibilities • What other information is related to the question? Which information is most useful? o Thigmotropism would not play a direct role in the sugar content or ripening time of the grapes. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o Grapes are thigmotropic vining plants, which means they need to wrap themselves around objects for support. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: This question asked you to assess the importance of thigmotropism. Answering this question correctly depended on your ability to evaluate grapes and positive thigmotropism. If you got the correct answer, well done! If you got an incorrect answer, where did the process break down? Did you remember that positive thigmotropism differs from negative thigmotropism in that positive thigmotropism refers to growth around a supportive structure? Did you have trouble weighing the merits of positive thigmotropism to determine the correct answer? 34) B 35) E When the apical buds are removed, cytokinin will influence the development of lateral buds into branches. 36) C Application of gibberellin will increase the space between grape flowers giving the fruits more room to grow. 37) B 38) B 39) C 40) C The five steps that lead from auxin perception to auxin-induced gene expression are listed in Section 39.5. Version 1
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41) B An antisense copy of the gene for ethylene biosynthesis prevents the formation of ethylene and subsequent ripening of transgenic fruit. The antisense strand is complementary to the sequence for the ethylene biosynthesis gene. After transcription, the antisense mRNA pairs with the sense mRNA, and the double-stranded mRNA cannot be translated into a functional protein. Ethylene is not produced, and the fruit does not ripen. 42) C Chlorophyll absorbs light in the red spectrum. So light passing out of a leaf will contain less red wavelengths. 43) D 44) C 45) A
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Clarify Question • What is the key concept addressed by the question? o This question is asking about the mode of transport from the roots to the stem for abscisic acid. • What type of thinking is required? o You are being asked to take what you already know and apply it to the movement of abscisic acid within a plant. • What key words does the question contain and what do they mean? o Abscisic acid, which is a plant hormone. o Transpirational water loss, which is the evaporation of water from the surface of a plant. Gather Content • What do you already know about transportation of materials within a plant? How does it relate to the question? • Xylem, which is composed of vessels and tracheids, moves water and other materials from the roots up through the shoots to the leaves. • Abscisic acid is made in the roots of plants. Consider Possibilities • What other information is related to the question? Which information is most useful? o Travel between cell walls or from cell to cell would be very inefficient. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o Abscisic acid is synthesized in the roots, and must travel upward. The xylem and tracheids carry materials upward to the stem and leaves. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o This question asked you to assess the route through which abscisic acid moves from the root to the stem of the plant. Answering this question correctly depended on your ability to use the characteristics of transport within a plant in a new situation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that abscisic acid is made in the roots, or that xylem carries material upward from the roots to the stem and leaves? Did you have trouble extending the routes of transport within a plant to determine the correct answer? 46) C
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Clarify Question • What is the key concept addressed by the question? o This question is asking about the role of phytochrome in plants. • What type of thinking is required? o This question is asking you to evaluate-the importance of phytochrome. • What key words does the question contain and what do they mean? o Phytochrome, which is a pigment-containing protein. Gather Content • What do you already know about the role of phytochrome in plants? How does it relate to the question? o Phytochrome transduces information. o One of the functions of phytochrome is to activate the transcription of light-regulated genes. Consider Possibilities • What other information is related to the question? Which information is most useful? o If phytochrome absorbed green wavelengths of light, the tissue in which it occurred would not appear green. o Phytochrome does not play a direct role in the reactions of photosynthesis. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o To answer this question, you must connect phytochromes with the Version 1
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indirect role that they play in photosynthesis. Phytochrome activates the expression of genes that code for photosynthesis-related proteins like the proteins necessary for chloroplast development. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: This question asked you to evaluate the function of phytochromes. Answering this question correctly depended on your ability to evaluate the activities that occur in tissue that has phytochromes present. If you got the correct answer, well done! If you got an incorrect answer, where did the process break down? Did you remember that phytochromes play an indirect role in photosynthesis? Did you have trouble weighing the merits of the presence of phytochromes to determine the correct answer? 47) B
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Clarify Question • What is the key concept addressed by the question? o This question is asking about the differences that occur in the structures of indoor vs. outdoor plants. • What type of thinking is required? o This question is asking you to evaluate-the conditions around indoor and plants grown outside. • What key words does the question contain and what do they mean? o Indoor, which in this context refers to plants that have relatively constant conditions in which to grow. o Outside, which in this context refers to plants that grow in conditions that are not modified by humans. Gather Content • What do you already know about growth of protected vs. exposed plants? How does it relate to the question? o Plants grown inside are typically grown in light, moisture, and other conditions that are as near optimal as humans can manage. o Plants grown outside are subject to the extremes of the weather and environment. Consider Possibilities • What other information is related to the question? Which information is most useful? o Stem thickness is not regulated by auxin. o Phytochrome does not play a role in stem thickness. Choose Answer
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Stem thickness is something that can be the result of thigmomorphogenesis. o Plants grown outside would be subject to the force of the wind, which would result in the thickening of the stem via thigmomorphogenesis to withstand the force of the wind. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: This question asked you to evaluate the differences between plants that grow indoors vs plants that grow outside. Answering this question correctly depended on your ability to evaluate plant responses in the different environments. If you got the correct answer, well done! If you got an incorrect answer, where did the process break down? Did you remember that indoor plants do not face the environmental pressures that plants grown outside do? Did you have trouble weighing the merits of indoor vs outside conditions to determine the correct answer? 48) D
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Clarify Question • What is the key concept addressed by the question? o This question is asking about seasonal fluctuations in the levels of cytokinins. • What type of thinking is required? o This question is asking you to evaluate-the changes that occur in cytokinin levels in plants as the seasons change in a temperate climate. • What key words does the question contain and what do they mean? o Temperate, which refers to climates that have moderate temperature changes between seasons. o Cytokinin, which are plant hormones that promote cell division in plants. Gather Content • What do you already know about cytokinin levels and seasonality? How does it relate to the question? o Highest growth rates for temperate plants occur in warmer months. o In the Winter, cytokinin levels drop in temperate plants. This places buds into a state of dormancy during the cold and dark Winter. This will protect the delicate tissues until the Spring when cytokinin levels will increase again and buds will break dormancy and grow. Consider Possibilities • What other information is related to the question? Which information is most useful? o During warmer months, biochemical activities and plant growth would occur at a higher rate than they would in colder months. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o To answer this question, you must connect the ideas of cold weather and the inhibition of metabolic activity. This is adaptive, because plant growth at this time would leave the tissues vulnerable to damage due to freezing. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: This question asked you to evaluate the importance of seasonal changes on cytokinin activity. Answering this question correctly depended on your ability to evaluate how living tissues react to temperature changes. If you got the correct answer, well done! If you got an incorrect answer, where did the process break down? Did you remember that freezing temperatures destroy living tissue? Did you have trouble weighing the merits of plant growth to environmental extremes to determine the correct answer? 49) A 50) A 51) A 52) A
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Clarify Question What is the key concept addressed by the question? ● Can you identify the type of plant growth response based on evidence? What type of thinking is required? ● This is an analyze question because you have to break plant growth responses into their component pieces to understand how they function. ● This question is asking you to identify key factors that qualify different types of plant growth responses. Gather Content What do you already know about plant growth responses? What other information is related to the question? ● Phototropisms are directional growth responses in stems toward blue light. They are regulated by auxin. ● Gravitropism is the growth response to a gravitational field. Accumulations of auxin on one side of a root or shoot affect cell elongation. Shoots bend away from gravity, while roots bend toward gravity. ● Photomorphogenesis is a nondirectional light-triggered development, often controlled by phytochrome. ● Thigmotropism is a permanent directional growth of a plant toward or away from a physical stimulus. ● Thigmonastic responses are independent of the direction of stimulus and involve reversible changes produced by changes in turgor pressure. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● The question indicates that lazy mutants show changes to directional growth, indicating a tropism. ● The specification of an affect on auxin distribution could apply to either phototropism or gravitropism. Version 1
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● However, the fact that lazy causes roots to grow in the wrong direction makes gravitropism the best choice. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended not only on distinguishing between different plant growth responses, but on your ability to break down, or analyze, the differences. If you got an incorrect answer, did you remember that auxins affect directional movement in response to light or gravity, or that the fact that roots were growing in the wrong direction made it more likely to be gravitropism? Did you have trouble breaking down the different plant growth responses to determine the correct answer? 53) Section Break 53.1) D 53.2) C 53.3) A
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Chapter 40 13e CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 1) Pea plants are self-pollinators. What can you further deduce about peas? (Check all that apply.) A) Peas will be moreresistant to garden pests than other plants. B) Peas are lesslikely to invade highly variable natural environments than other plants. C) A gardenerplanning to collect heirloom seeds can plant different varieties of peas neareach other. D) Peas will be moreresistant to new plant diseases. E) To perform his pea cross-pollinationexperiments, Gregor Mendel must have first removed the stamens fromflowers to prevent self-pollination.
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 2) Angiosperms use which temporary reproductive structures that are not present in any other group of plants? A) cones B) carpels C) receptacles D) flowers E) seeds
3)
What is the process that eventually leads to the death of a plant? A) outcrossing B) dichogamy C) abscission D) perennial E) senescence
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4) The developmental transition during which plants become able to respond to external and/or internal signals that promote flowering is known as A) cloning. B) initiation. C) abscission. D) perennial development. E) phase change.
5) Your friend examines an ivy vine growing on the side of a campus building and says, “Look – some of the branches on this plant have a different morphology. The leaf shapes and patterning are different, and there are flowers on some branches but not others. There must have been a mutation!” You respond, A) “I think you’reright. Maybe there was a mutation in the LEAFY ( LFY) gene, andthe loss of LFY has promoted flowering and had pleiotropic effects onleaf morphology.” B) “No, those brancheshave just undergone phase change. Now they’re in the adult form, and havebecome competent to respond to flowering signals.” C) “I think you’reright. Maybe the embryonic flower ( emf) gene is beingoverexpressed, and that’s causing flowers to form.” D) “No, those morphological changes are just evidence that this plant’senvironment has changed during its lifetime.”
6) One way to improve crop productivity is to modify flowering time. This can allow for multiple growing seasons in one year, and can also increase grain production because a smaller plant has lower resource needs. You are approached by an agricultural company that wants to create an early-flowering transgenic plant. Using your knowledge of Arabidopsis genetics, which genetic modifications would you suggest?
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A) Inhibition of the embryonic flower ( EMF) gene or overexpression of the LEAFY ( LFY) gene would work. B) Inhibition of the LEAFY ( LFY) gene or overexpression of the embryonic flower ( emf) gene would work. C) Inhibition of either the embryonic flower ( emf) gene or the LEAFY ( LFY) gene would work. D) Early flowering is not possible in Arabidopsis, and is not likely to be possible in other plants.
7) Arabidopsis plants with a mutation in the gene embryonic Flower ( EMF) produce flowers almost immediately after germination, before shoot growth occurs. What is the normal role of this gene? A) The wildtype EMF allele causes growth of flowers in the embryo. B) The wildtype EMF allele causes death of the shoot tissue. C) The wildtype EMF allele prevents flowering from happening too soon. D) The wildtype EMF allele prevents phase change and facilitates flower determination.
8) Interrupting the night with a flash of light can trigger flowering in a long-day plant. Why doesn't introducing a short period of darkness during the day cause a short-day plant to flower? A) Sunlight containsenough far-red light to inhibit phytochrome induction of flowering. B) A brief dark period is not sufficient to trigger flowering. C) Phytochrome isonly active in the dark. D) The circadianclock is less responsive during the day than at night. E) The phytochromeresponse also requires cool nighttime temperatures.
9)
Which of the following statements about flowering plants is TRUE?
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A) A short-day plant requires nights longer than a certain critical period to trigger flowering. B) A long-day plant requires nights shorter than a certain critical period to inhibit flowering. C) A short-day plant requires daylight of short wavelengths. D) A long-day plant requires long wavelengths during the night. E) A long-day plant requires long days alternating with short days.
10) Why do many plants use the photoperiodic pathway to regulate the timing of flower formation? A) Flower petalscarry out high levels of photosynthesis and require high light conditions. B) A minimum amountof light is always necessary for flowering. C) This allows plantsto link flowering to temperature, which corresponds to the season whenconditions are optimal. D) This allows plantsto link flowering to day length, which corresponds to the season whenconditions are optimal.
11) You buy a Schlumbergera plant, also known as a Christmas Cactus, to decorate the desk where you study late into the night. It is now December, and there are no signs of flower buds forming. What is the most plausible explanation for the lack of flowers? A) Flowering in thisplant is controlled by both day length and temperature. The warm room andextended exposure to light are preventing flower formation. B) The room is toocold for a cactus plant, which requires hot, desert conditions to flower. C) Cacti aregymnosperms, not angiosperms, and thus do not form flowers. D) As a long-dayplant, the cactus requires a high light to dark ratio to flower, so it must beexposed to more sunlight.
12) The owner of a plant nursery is introducing the new night janitor to his duties. “Behind this door are the poinsettias,” she said, “Please don’t clean this room, and leave the door closed.” Why might the owner say this?
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A) Poinsettias areshort-day plants that require a long uninterrupted period of darkness toflower. Even a short flash of light at night could prevent flowering. B) Poinsettias arevery sensitive to the chemicals used in cleaning, which can interfere with thegibberellin-dependent pathway and disrupt flowering. C) Poinsettias are tropical plants and require constant warm temperatures forflower formation. D) Poinsettias arelong-day plants that require a long period of light for flower formation, andthis light might disrupt the day-night cycles of other plants outside theroom.
13) At a certain point in the flowering process, shoots become committed to making a flower. This is called A) apomixis. B) bilateralism. C) phase change. D) competence. E) floral determination.
14) Competence means that a plant is_________blank, while determination means that a plant tissue_________blank. The acquisition of flowering competence is an example of a_________blank. A) capable ofresponding to signals that trigger a fate change; remains capable of adoptingmore than one possible developmental fate; phaseolus B) unresponsive tosignals that trigger a fate change; is committed to a specific developmentalfate; fate change C) in the process ofresponding to signals that trigger a fate change; was driven to adopt anabnormal developmental fate by transgene expression; flowerization D) capable ofresponding to signals that trigger a fate change; is committed to a specificdevelopmental fate; phase change
15) In the ABC model of floral determination, a different combination of the three genes specifies each floral organ. Which gene works in combination with the other two?
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A) A B) B C) C D) florigen E) ethylene
16) At the Beautiful Mutants Flower Shop, a variety of unique mutant plants are sold. What would be the best flower to give to a friend who is allergic to pollen? A) "Superhunk" -- a plant with a mutation in the class A genes. B) "BeautifulInnocence" -- a plant with a mutation in the class C genes. C) "Clockface"-- a plant with a mutation in the CYCLOIDEA gene. D) "Suspense"-- a plant with a mutation in the LEAFY gene.
17) Flowering can be regulated by light, temperature, gibberellin levels, or internal factors. What do all of these different flowering pathways have in common? A) All four pathwaysresult in a decrease in LEAFY ( LFY) expression, which inducesflowering. B) All four pathwaysresult in an increase in CONSTANS ( CO) expression, which inducesflowering. C) All four pathwaysresult in an increase in LEAFY ( LFY) expression, which inducesflowering. D) All four pathwaysresult in a decrease in CONSTANS ( CO) expression, which inducesflowering.
18) A seed that lands in the forest soil is homozygous mutant for the LEAFY ( LFY) gene, and as a result does not produce any functional LEAFY protein. What do you predict will happen during the development of this seed?
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A) It will germinateand grow vegetatively, but will never produce flowers. B) It will fail togerminate. C) It will germinate and immediately produce flowers. D) It will germinateand grow vegetatively. It will only develop flowers if it is from a speciesregulated by the autonomous flowering pathway.
19) A seed that lands in the forest soil is homozygous mutant for the CONSTANS ( CO) gene, and as a result does not produce any functional CONSTANS protein. What do you predict will happen during the development of this seed? A) It will germinateand grow vegetatively, but will never produce flowers. B) It will fail togerminate. C) It will germinateand grow vegetatively, and then it will produce flowers earlier thanwildtype. D) It will germinate and grow vegetatively. If it is from a photoperiodicspecies, it will fail to produce flowers.
20) How could you monitor flower determination in a plant that is mutant for all three class E SEP genes? A) You cannot,because the class E mutant cannot make proper flowers. B) Look forformation of sepals and petals. C) Measure levels ofSEP protein. D) Measure levels ofLEAFY and AP1 proteins.
21)
Evolutionarily, floral parts represent modified A) stems. B) leaves. C) roots. D) stolons. E) buds.
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22) Ovules develop within the ovary, which is located in the swollen lower portion of which floral organ? A) anther B) stamen C) filament D) stigma E) pistil
23)
Which of the following isnot a floral structure? A) endosperm B) calyx C) corolla D) stigma E) style
24) Your botany instructor likes to tell nerdy jokes, like this: "I wanted to buy a pink Toyota Corolla, but the dealer only had a green Calyx available." Impress your instructor with a clever response to this joke. A) "Oh, I wouldhave chosen the blue Receptacle." B) "Those aregreat cars, but the pinecone tires don't roll very well." C) "Me too! But Icould only afford the yellow Androecium." D) "The factorymust have run out of class A genes."
25) A researcher is investigating the morphology of complete flowers. Which of the following organs must his flowers contain?
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A) calyx, corolla,receptacle, and carpels B) calyx, corolla,carpels, and ovules C) calyx, corolla,stamens, and anthers D) calyx, corolla,carpels, and pistils E) calyx, corolla, androecium, and gynoecium
26) A genus of primarily wind-pollinated plants includes one unusual species that has evolved to be pollinated by insects. Several morphological changes have accompanied this adaptation. The _________blank are more colorful, there is a nectary at the base of the _________blank, the _________blank are shorter and produce sticky pollen, and the _________blank are stickier for enhanced pollen capture. A) petals; stamens; sepals; carpels B) petals; sepals; stamens; carpels C) stamens; carpels; petals; sepals D) petals; sepals; carpels; stamens
27) Some species of orchids attract pollinating Hymenoptera (bees and wasps) with flowers that closely mimic the appearance of a female insect. As the male attempts to mate with the flower, he becomes loaded with pollen, helping the plant to reproduce. If one of these orchid plants acquired a loss-of-function mutation in a CYCLOIDEA-like gene, what do you predict might happen? A) The mutationwould quickly spread through the population. B) The mutant plantswould have fewer available resources to devote to nectar production. C) The mutant plantswould attract larger numbers of pollinating male insects. D) The mutationwould fail to spread in the population.
28)
Microspore mother cells produce microspores. What do microspores then develop into?
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A) egg cells B) pollen grains C) synergids D) endosperm E) megaspores
29)
Which of the following statements about the angiosperm embryo sac is FALSE? A) It contains eight nuclei. B) It is the gametophyte generation of the plant. C) The nuclei within the embryo sac are diploid. D) The synergids flank the egg cell. E) The embryo sacnuclei are the product of mitotic division of a megaspore.
30)
Which structure contains the angiosperm egg? A) style B) endosperm C) anther D) embryo sac E) stigma
31) You are a landscape architect working on the grounds of a large estate. After you plant a dozen trees, the owner says, "There's been a mistake. The flowers on some of these willow trees look totally different! I specifically asked for Salix alba. You must have planted two different species." You refer to your tree guide, and read: " Salix alba - species of willow native to Europe and Asia, noted for the white undersides of leaves. Insect pollinated, dioecious. Grows 10-30m tall." How do you respond to the client?
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A) "Sorry aboutthat sir, I will dig up the wrong trees right away." B) "Don't worry,the trees with the smaller flowers just haven't undergone phase changeyet." C) "Don't worry,when the shorter trees reach full size, they will grow the other kind offlower." D) "Don't worry, Salix alba is dioecious, meaning each tree has either male or femaleflowers. That is why they look different."
32) Thanks to a novel recessive mutation, a certain plant species has begun to invade colder Arctic regions outside of its normal range. However, this cold-tolerant mutation has not yet become fixed in the population. A second mutation arises that promotes self-pollination. Do you predict that the self-pollination allele will be selected for in the Arctic regions? Why or why not? A) Yes. Theself-pollinated plant is more likely to maintain the cold-tolerant mutation,and plants in the Arctic are unlikely to be visited by pollinators. B) No. Outcrossing isalways beneficial, since it enhances genetic diversity. C) No. Plants thatproduce flowers must be cross-pollinated for proper seed development. D) Cannot make aprediction from the information given. It depends on whether the plant isnormally insect-pollinated or wind-pollinated.
33) Which of these characteristics would most likely discourage self-pollination in a flower with both stamens and pistils? A) many more stamensthan pistils B) long pistils andshort stamens C) long stamens andshort pistils D) windpollination E) determinantplants
34) Oaks, birches and corn produce both staminate and pistillate flowers on the same plant. What term describes this type of plant?
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A) monoecious B) dioecious C) hermaphroditic D) complete E) determinant
35)
Flowering plants use animals or wind to transfer_________blank between flowers. A) microspores B) megaspores C) ovules D) seeds E) pollen
36) In a wind-pollinated species, which of these floral parts is likely to be inconspicuous or absent? A) receptacle B) stamens C) pistils D) petals E) stigmas
37)
Early seed plants were pollinated by_________blank, as are present-day conifers. A) beetles B) bees C) trilobites D) wind E) water
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38)
Which of these characteristics does not promote outcrossing in flowering plants? A) self-incompatibility B) dioecism C) monoecism D) physical separation of flower parts E) apomixis
39)
Which of the following factors is LEAST likely to attract pollinators to a flower? A) the amount ofnectar B) odor C) color of theflower in visible light D) color of theflower in UV light E) taste of theovules
40)
Which of the following statements about plant reproduction is incorrect? A) Monoecious plants can have male and female flowers on the same plant. B) Dioecious plants have male and female flowers on different plants. C) Self-pollinatingangiosperms are usually adapted to stable habitats. D) Outcrossing promotes genetic diversity. E) Self-pollinatedplants must be visited by pollinators for fertilization to occur.
41) Some flowers have distinctive patterns that only reflect ultraviolet light and therefore are invisible to humans. Which statement about such markings isnot correct?
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A) The ultravioletpatterns are highly visible and attractive to bees. B) Carotenoidpigments are responsible for the ultraviolet patterns. C) The ultravioletpatterns often form a conspicuous central bull's eye or identify the bestlanding sites. D) The ultravioletpatterns repel birds and bats from the flowers. E) Flowers withultraviolet patterns usually appear yellow or orange to humans.
42)
Which of these is not an example of coevolution between flowers and pollinating bees?
A) Bees have tongues to lap up nectar. B) Some bees are hairy to collect and carry pollen. C) Flowers have ultraviolet markings visible to bees but invisible to most other insects. D) Some flowers are bright red with long tubes to hold nectar. E) Bees have strong preferences for particular types of flowers and remember where the plants are located.
43) Many plants devote significant resources to growing colorful, fragrant flowers filled with nectar. What does this illustrate the importance of? A) nutrient storagein seeds B) long-term nutrientstorage in perennial plants C) outcrossing D) chemical signalingamong plants
44) You and your neighbor each have a holly bush in your yards. You carefully water and care for your bush, but it fails to produce berries. Your neighbor, on the other hand, neglects his holly, yet it produces gorgeous red berries each year. Finally, in frustration, you replace your holly with a rose bush. The next year, your neighbor’s holly bush has no berries at all. What happened?
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A) Roses compete forthe same insect pollinators as holly bushes. B) Holly plants aredioecious. Yours was a male that was needed to pollinate the neighbor’sfemale. C) Roses secrete achemical that inhibits the reproduction of neighboring plants. D) The neighbor’sbush became infected with the same disease that yours had.
45)
What process results in the formation of the endosperm and the embryo in angiosperms? A) alternation ofgenerations B) hydrolysis C) determinategrowth D) doublefertilization E) secondarygrowth
46) Pollination begins when pollen is transferred from the_________blank to the_________blank of a flower. A) anther; ovary B) anther; receptacle C) anther; stigma D) stigma; embryo sac E) synergid; egg
47)
Which step isnot involved in the fertilization of angiosperm flowers?
A) Pollen istransported to a stigma of a flower. B) When pollen reachesthe stigma of a flower, it begins to grow a pollen tube that pierces thestyle. C) The style of thepistil contracts to bring the sperm closer to the embryo sac. D) The pollen tubegrows until it reaches the ovule in the ovary. E) Doublefertilization produces an embryo and the endosperm.
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48)
What is the best description of double fertilization in angiosperms?
A) One sperm fertilizes the egg, which develops into the embryo; the other sperm fertilizes the ovary, which becomes the fruit. B) One sperm fertilizes the egg, which develops into the embryo; the other sperm fertilizes the polar nuclei, which forms the endosperm. C) One sperm fertilizes the egg, which develops into the embryo; the other sperm fertilizes the polar nuclei, which forms the seed coat. D) One sperm fertilizes the egg, which develops into the embryo; the other sperm produces the pollen tube. E) One pollen grain fertilizes the embryo sac; the other sperm fertilizes the pollen grain.
49)
“Germination” can refer to two different events A) the arrival of thepollen grain at the ovule, and the growth of the seedling from the
seed. B) the development ofthe flower, and the growth of the seedling from the seed. C) the growth of thepollen tube into the embryo sac, and the growth of the seedling from theseed. D) the development ofthe fruit from the ovary, and the growth of the seedling from the seed.
50) You go to the movies with a friend, and he refuses to share your popcorn. He says that he heard that movie theatre popcorn is triploid. What is the most likely explanation for this? A) Most corn isgenetically modified by large agricultural companies. B) The butterytopping on movie theatre popcorn causes chromosomal abnormalities. C) Popcorn is madefrom a different species of maize than regular corn. D) All popcorn istriploid, because the starchy part of the kernel is triploid endospermtissue.
51) If a pollen grain fails to generate two sperm cells, what is the most likely result of pollination? Version 1
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A) Half the seedswould develop fine, but the other half would die. B) The resultingprogeny would be haploid. C) The seeds wouldlack either embryos or endosperm, and so would be nonviable. D) The endospermwould be smaller.
52)
What are the "seed leaves" that grow from bulges on the embryo called? A) radicles B) embryo sacs C) petioles D) cotyledons E) ovules
53)
The HOBBIT gene in an embryo helps to control the development of what structure? A) cotyledon B) endosperm C) root D) epicotyl E) root hair
54)
Which of the following statements about plant development is true? A) The radial axis of the developing embryo develops before the root-shoot axis. B) A single gene isresponsible for the control of all root and shoot formation. C) The MONOPTEROS gene ( MP) stimulates chlorophyll synthesis inseeds. D) Gibberellic acid is important in root-shoot axis formation. E) Cells nearest to the suspensor ultimately form the root.
55) What do the two daughter cells generated by the first asymmetric division of the plant zygote become? Version 1
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A) the suspensor andthe embryo B) the epicotyl andthe hypocotyl C) the root and theshoot D) the egg andpollen E) the xylem and thephloem
56)
Which of the following statements about plant embryo development is correct?
A) The suspensor forms from the shoot apical meristem before development of the root apical meristem. B) The development of the shoot and root apical meristems is controlled independently. C) The plant hormoneabscisic acid is important in the development of the shoot-root axis. D) The protoderm establishes the procambium tissue in the young plant embryo.
57)
What does the globular stage of plant embryo development give rise to? A) a heart-shapeddicot embryo B) the suspensor ofthe germinating seed C) a double monocotembryo D) the monocotscutellum E) the rhizoid of Fucus
58)
What did experiments with the brown alga Fucus help to determine? A) The cytoplasm isevenly distributed throughout the algal zygote. B) The thallus anchorsthe alga to the surface on which it lives. C) Light and gravitydo not affect rhizoid orientation. D) Magnesium gradientsare important for cell wall formation. E) A cell wall isrequired for the zygote to "remember" where a rhizoid should form.
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59) Which structure can still develop normally in an embryo with mutations in both the SHOOTMERISTEMLESS ( stm) gene and the HOBBIT gene? A) root cap B) shoot apical meristem C) root apical meristem D) leaf primordia E) cotyledons
60)
What is the name of the meristematic tissue that gives rise to future vascular tissue? A) procambium B) cork cambium C) groundmeristem D) dermal tissue E) protoderm
61) What is the name of the elongated structure that links the embryo to the nutrient tissue of the seed? A) suspensor B) cotyledon C) epicotyl D) style E) ovule
62)
Which of these structures does not begin development during embryogenesis?
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A) apical meristem B) vascular tissue C) floral primordia D) leaf primordial E) ground tissue
63)
Which of these is not part of a seed? A) endosperm B) embryo C) diploid cells D) seed coat E) fruit
64)
Endosperm tissue of angiosperms has what ploidy level? A) n B) 2n C) 3n D) 4n E) 8n
65) Germination requires the use of metabolic reserves in the seed. Which of these compartments contains starch used to fuel early seedling growth? A) amyloplasts B) protoplasts C) chloroplasts D) chromoplasts E) mitochondria
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66)
Which of the following is not a feature of a seed? A) It contains a protective coat formed from the outer layers of ovule cells. B) The embryo is surrounded by nutritive tissue or has cotyledons that contain nutritive
tissue. C) It contains a large percentage of water to support the embryo. D) It is a complex structure that allows the embryo to be dispersed to distant sites. E) Environmental signals such as light or temperature can trigger germination.
67)
Why do oils form a significant part of the nutritional reserves in many seeds? A) Oils help keep theembryo hydrated, allowing the seed to survive in dry habitats. B) The oils reducethe density of the seed and allow for water dispersal. C) Oils contain more mineral nutrients than carbohydrates. D) Oils store twiceas much energy as an equivalent mass of starch. E) Hormones diffusemore quickly through oils.
68)
What is the term for the single cotyledon within the kernels of cereal grains? A) aleurone B) hypocotyl C) dicot D) scutellum E) amyloplast
69)
What is the portion of a dicot seedling below the cotyledons called? A) internode B) epicotyl C) hypocotyl D) plumule E) subcotyl
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70) Stratification refers to the extended exposure to_________blank that is required for some seeds to germinate. A) long wavelengths of light B) lowtemperatures C) high relative humidity D) short daylengths E) clay soil particles
71)
Which structure doesnot represent a mode of vegetative reproduction? A) runners B) rhizoids C) adventitiousplantlets D) suckers E) rhizomes F) stolons
72) What are plants that flower only once before they die, normally after two seasons of growth, called? A) annuals B) biennials C) perennials D) monocots E) dicots
73) Which part of the seed produces hydrolytic enzymes that break down the starchy endosperm during seed germination?
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A) scutellum B) amyloplasts C) aleurone layer D) plumule E) coleorhiza
74) When a seed germinates, the embryo emerges from its dormancy and begins which phase of the plant life cycle? A) sporophyte generation B) gametophyte generation C) dicotgeneration D) monocotgeneration E) alternategeneration
75)
Which of the following statements about the epicotyl is true? A) It remains in the ground after a seed has germinated. B) It is the portion of the stem axis that is directly below the cotyledons. C) The shoot apical meristem of a seedling is located just above it. D) It takes up most of the volume within a monocot or dicot seed. E) It forms immediately above the secondary roots of a seedling.
76) Despite its name, Kentucky Bluegrass is a widespread turfgrass used for lawns throughout the United States. In some regions, strains have developed desirable disease-resistant properties. However, Kentucky Bluegrass typically develops by apomixis. Plant breeders say this creates both a challenge and an opportunity for engineering novel strains. Why?
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A) In apomixis, newplants develop from underground horizontal stems. This allows for fastpropagation of new strains, but all progeny are identical to theparent. B) Plants thatdevelop by apomixis are naturally tolerant of herbicides. As a result,herbicide tolerance genes cannot be used as selectable markers for a transgene,but herbicides can be used to keep the resulting culture pure. C) Since the progenyof apomixis are triploid, hybrids have an imbalance of parental genes. However,this may be desirable if a higher proportion of one allele is beneficial. D) If a seed developsby apomixis, it will be identical to its parent. Hybridization with anotherstrain requires special techniques. However, once a hybrid strain is developed,apomixis ensures its reliable propagation.
77) Dandelions develop seeds by apomixis. What benefits does this strategy provide over vegetative or sexual reproduction? A) Apomixis makesthe dandelions more resistant to herbicides. B) Apomixis providesthe benefits of seed dispersal, while maintaining a genome adapted to a givenclimate. C) Apomixis isbeneficial in sheltered areas where wind pollination would be difficult. D) Apomixis isbeneficial for plants that attract a diverse mix of bees and otherpollinators.
78) Which tissue cannot divide to give rise to identical progeny in a plant that reproduces asexually? A) root B) stem C) leaf D) pollen grain E) ovule
79)
Which of the following statements about plant tissue culture is false?
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A) Virus-free cropspecies can be propagated by culturing meristems. B) Individual cells can give rise to whole plants through tissue cultures. C) Synthetic hormonescan be used to selectively promote root or shoot formation. D) Callus tissue canonly form roots, not shoots. E) A callus is a massof undifferentiated cells.
80) Browsing through a seed catalog, you are tempted to order several beautiful floral varieties, but worry that you will spend too much on your garden every year. Which plants should you buy? A) herbaceousperennials, which will come back year after year B) woody perennials,which require little space and few resources C) annuals, whichwill come back year after year D) biennials, whichwill last twenty years before they die
81) Heirloom plants are treasured for their flavorful produce and true-breeding progeny that allow gardeners to avoid repeatedly purchasing seed from agribusiness conglomerates. What special effort is required to save seed from heirloom biennials such as carrots? A) Since carrotsproduce large roots, they do not devote many resources to seed development. Theroots must be trimmed before collecting seed. B) Since carrotsbuild up so much beta-carotene, they do not devote many resources to seeddevelopment. A yellow carrot variety will produce better seeds than a darkerone. C) Since carrots arerelated to wild weeds, they are often cross-pollinated. The green top must bebagged to ensure self-pollination. D) Biennials do notproduce seed until the second year of growth. Although carrot roots arenormally harvested after one season, they must be allowed to grow another yearfor seed collection.
82)
Which of the following events is not a characteristic of successful seed germination?
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A) The radicle breaks through the seed coat. B) The shoot becomes photosynthetic. C) The embryo becomes desiccated. D) New growth occurs at the meristems. E) The seedling orients itself relative to gravity.
83) Your friend has never gardened before. When none of the seeds he planted germinate, he asks you to suggest why. Which is the best explanation of what occurred? A) The monocot seeds he used were only able to produce a single cotyledon each. B) The seeds were planted too deeply and used up their reserves before reaching the surface and sunlight. C) The suspensor failed to develop into an embryo within each seed. D) All seeds require fire in order to germinate. E) Seeds take more than one season to germinate.
84) Why can scratching or chipping the seed coat speed up the germination of hard-coated seeds like alfalfa? A) The mechanicalstress activates hydrolytic enzymes. B) Water and oxygen can enter the seed to reach the embryo more quickly. C) Carbon dioxide canenter the seed and stimulate photosynthesis. D) Bacteria or fungican enter the seed and release growth factors. E) Damage to the seedcoat triggers the aleurone layer to release amylase.
85) Scientists have confirmed by carbon dating that seeds dormant for up to 2000 years can successfully germinate. Based on the requirements for germination, what research expedition should you join in order to retrieve some ancient but viable seeds?
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A) A trip toIndonesia, where the civet cat eats and expels coffee beans, producing agourmet coffee known as Kopi Luwak. B) A trip to theIrish marsh, where wet peat creates anaerobic conditions, and your colleagueshope to unearth a bog mummy. C) A trip to theBurgess Shale in Canada, where your paleontologist colleagues have foundfossils from the Cambrian era. D) A trip to the aridDead Sea region, where your historian colleagues have found a storeroom ofwax-sealed jars.
86) The spider plant, Chlorophytym comosum, is a popular houseplant for both its appearance and its air-purifying capabilities. It’s also one of the most cost-effective house plants to buy because it is quite easy to propagate new plants from your initial purchase. As the spider plant grows, you’ll see leaves growing directly out of the soil, but you’ll also see shoots grow out of the soil and sprout little plantlets (sometimes called spiderettes) at their ends. If you cut these spiderettes from the stolon and place them in a cup of water, you’ll see roots form directly from the shoot. Shortly afterward you can plant these little spider plants in their own pots. What kind of reproduction is being described for the spider plant? A) Vegetative growth B) Apomixis C) Self-pollination D) Protoplast regeneration E) Double fertilization
87)
Which of the following is an event in the typical life cycle of a flowering plant? A) A megagametophyte makes polar nuclei by mitosis. B) A microgametophyte makes sperm by meiosis C) A microgametophyte fertilizes an egg to form a zygote. D) A megagametophyte is transported to another flower by wind or an animal. E) A microgametophyte fertilizes a megagametophyte to form an embryo.
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88) Researchers studying orange trees, Citrus sinensis, observed that application of gibberellic acid to the shoot apical meristem (SAM) inhibits flowering by continuing vegetative development of the SAM, even in plants that have produced fruit in previous years. However, when applied to a citrus bud coincident with sepal formation, gibberellic acid no longer has an inhibitory effect on flowering. What process is being inhibited by gibberellic acid in this case? A) Floral determination B) Phase change C) Double fertilization D) Pollination E) Meiosis
89) Corn, Zea mays, is a monoecious plant with imperfect flowers (called tassels and silks) that relies primarily on wind pollination. The staminate tassels are located at the top of the shoot, while the pistillate silks are found lower down on the plant. Which gene will NOT be expressed in the tassels? A) Zea mays APETALA1 (ZAP1), a class A gene B) Zea mays MADS16 (ZMM16), a class B gene C) SILKY1 (Sl1), a class B gene D) Zea mays AGAMOUS1 (ZAG1), a class C gene E) Zea mays MADS8 (ZMM8), a class E gene
SECTION BREAK. Answer all the part questions. 90) Choose the LETTER of the best match from the following: A. hypocotyl B. endosperm C. scutellum D. radicle E. epicotyl
90.1)
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The stem axis of the embryo below the cotyledons in some seedlings.
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90.2)
A single cotyledon found in the kernels of cereal grains.
90.3)
Nutritive tissue within angiosperm seeds.
90.4)
The part of the stem axis that extends above the cotyledons in some seedlings.
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Answer Key Test name: Chap 40_13e_Raven 1) [B, C, E]
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Clarify Question What is the key concept addressed by the question? • The question is asking about the consequences of self-pollination. What type of thinking is required? • Apply level: o You are being asked to take what you already know and apply it to the effects of self-pollination to a plant and the plants in the surrounding area. Gather Content What do you already know about pollination? What other information is related to the question? • Both pistils and stamens are found in the same flower on a selfpollinated plant. • Self-pollinated plants have lower genetic variability than crosspollinated plants. • Self-pollination is favored in environments that have greater stability. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Self-pollinated plants are not necessarily more resistant to garden pests or diseases. • If self-pollinating plants are grown next to each other, they maintain their own identities and traits, so different varieties could be easily differentiated. • To turn a self-pollinator into a cross-pollinator, the stamens must be removed.
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the characteristics of self-pollinating plants in a new situation. If you got an incorrect answer, did you remember that self-pollination removes the necessity for dispersion, or that self-pollinated plants maintain their own unique identities? Did you have trouble extending the characteristics of self-pollinated plants to determine the correct answer? 2) D 3) E 4) E 5) B
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Clarify Question What is the key concept addressed by the question? • This question is asking you to explain why one plant can have different morphologies and flowering patterns in different regions. What type of thinking is required? • Evaluate level: o This question is asking you to evaluate the reason that a single plant can exhibit different morphologies simultaneously. Gather Content What do you already know about flowers? What other information is related to the question? • Immature plants cannot produce flowers. • Phase change marks the time at which a plant has matured and can produce flowers. • Phase change may be obvious morphologically, but that is not always the case. • The LEAFY gene promotes flower formation. • The emf gene causes flowers to form abundantly. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The presence of flowers on the plant indicates that the plant has gone through phase change and is not immature. Since flowers are present in some but not all parts of the vine, it is unlikely that the emf gene is being overexpressed. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to evaluate the reason that a plant can have different morphologies in different branches. If you got an incorrect answer, did you remember that morphology can differ as a result of phase change, or the criteria to compare different morphologies includes the concept of phase change? Did you have trouble weighing the merits of variable morphology to determine the correct answer? 6) A
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Clarify Question What is the key concept addressed by the question? • The question is asking you to analyze different genes that influence flower production. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break emf and LEAFY genes into their component pieces to understand how they function. Gather Content What do you already know about EMF and LEAFY genes? What other information is related to the question? • EMF facilitates vegetative development, and must be suppressed to initiate flowering. • emf is a loss of function mutation that flowers immediately. • LEAFY is necessary for flower production. • If overexpressed, LEAFY results in early flowering. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Genetic patterns that cause early flowering are sought in this example. LEAFY, if overexpressed, causes early flowering, as does emf. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between emf and LEAFY, but on your ability to break down, or analyze, the causes of early flowering in Arabidopsis. If you got an incorrect answer, did you remember that early flowering can be initiated by the inheritance of emf, or that overexpression of LEAFY would also induce early flower formation? Did you have trouble breaking down the genetic causes of early flowering to determine the correct answer? 7) C 8) B
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Clarify Question What is the key concept addressed by the question? • This question is asking you to analyze the mechanics of flowering within a short-day plant. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break the flowering mechanisms of long-day and short-day plants into their component pieces to understand how they function. Gather Content What do you already know about long-day and short-day plants? What other information is related to the question? • Long-day plants can be induced to flower by an extra burst of light. • Short-day plants and long-day plants are stimulated to flower by the length of uninterrupted periods of darkness. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Circadian clock responsiveness is not affected by the time of day, so this answer can be discarded. Phytochrome can be active during periods of light, so references to inactivation during daytime hours are not accurate. The correct answer lies in the idea that plants are affected by the length of uninterrupted darkness, therefore a brief exposure to the dark should not be expected to have an impact on the timing of flowering. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between the action of phytochrome and photoperiod in stimulating flower production, but on your ability to break down, or analyze, the mechanism of flowering regulation. If you got an incorrect answer, did you remember that flowering regulation includes the action of phytochrome, or that the period of uninterrupted darkness regulates flower production? Did you have trouble breaking down flowering regulation to determine the correct answer? 9) A 10) D 11) A
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Clarify Question What is the key concept addressed by the question? • The question is asking you to evaluate the cause of the lack of flower buds on a plant. What type of thinking is required? • Evaluate level: o This question is asking you to evaluate the lack of flower production in certain conditions. Gather Content What do you already know about flower production? What other information is related to the question? • Temperature is a variable that can affect flower production. • Some plants require vernalization, a period of cooling, before they flower. • Periods of uninterrupted darkness are also necessary for flower formation. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Cacti, as angiosperms, do form flowers. Since the student uses the desk where the plant is located to study, one would expect that this area has a greater temperature and a greater exposure to light that other surrounding areas. The lack of cool temperatures and the nearly constant presence of light could inhibit flower production. Reflect on Process
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to weight and judge the environmental conditions that are inhibiting flower production. If you got an incorrect answer, did you remember that some plants require cool temperatures to flower, or that photoperiod must also be within a specific range for flower production? Did you have trouble weighing the merits of the environmental variables relative to flower production to determine the correct answer? 12) A
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Clarify Question What is the key concept addressed by the question? • This question is asking about the role of light in the life cycle of poinsettias. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break poinsettia life cycles and the influence of photoperiod into their component pieces to understand how they function. Gather Content What do you already know about short-day and long-day plants? What other information is related to the question? • Short-day plants flower when the photoperiod falls below a critical level. • Even a short burst of light can interrupt the period of uninterrupted darkness that is required for short-day plants. • Long-day plants flower when the photoperiod exceeds a certain level. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The nursery manager is trying to ensure that the poinsettias have uninterrupted darkness. Long-day plants do not require this, but this is a requirement of short-day plants. Reflect on Process Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between long-day and short-day plants, but on your ability to break down, or analyze, the flowering requirements of a poinsettia. If you got an incorrect answer, did you remember that components of light requirements for flowering include periods of darkness, or that bursts of light would likely affect the required period of darkness for short-day plants? Did you have trouble breaking down the light requirements for flowering to determine the correct answer? 13) E 14) D 15) B 16) B
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Clarify Question What is the key concept addressed by the question? • This question is asking about genetic mutations that would cause a plant to be pollen-free. What type of thinking is required? • Evaluate level: o This question is asking you to evaluate the genetic causes of lack of pollen production. Gather Content What do you already know pollen? What other information is related to the question? • Stamens produce pollen. • Class B and Class C genes code for stamens. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The class C mutant would produce a flower consisting of petals and sepals, with no reproductive organs and thus no pollen. • The class A would code for the petals and the sepals. • The CYCLOIDEA mutant would be radially symmetric, but still have stamens and pollen. • The LEAFY mutant would never produce flowers at all. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to evaluate the type of mutation that would eliminate pollen production. If you got an incorrect answer, did you remember that pollen is produced in the stamens of a plant, or that Class B and Class C genes together specify the stamens? Did you have trouble weighing the products of different floral genes to determine the correct answer? 17) C 18) A
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Clarify Question What is the key concept addressed by the question? • This question is asking you to analyze the effects of the inheritance of mutated copies of the LEAFY gene. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break a mutation in the LEAFY gene and plant development into their component pieces to understand how they function. Gather Content What do you already know about flowering and the LEAFY gene? What other information is related to the question? • Flowers are necessary for reproduction in angiosperms. • The non-mutated form of the LEAFY gene is necessary for flower development. • If overexpressed, the LEAFY gene can lead to early flower production. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since the LEAFY gene is involved in flower production, mutated forms of this gene will not prevent germination and vegetative growth. • The autonomous pathway is amplified by normal LEAFY expression, so it would be unaffected by this mutant form of the gene. • Since the individual in this example is a homozygous mutant for lack of the LEAFY protein, this individual will not produce flowers. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between normal and mutant forms of the LEAFY gene, but on your ability to analyze the effects of this gene on a growing plant. If you got an incorrect answer, did you remember that the LEAFY gene is necessary for flower production, or that the plant in this example had a mutation that stopped the expression of this gene? Did you have trouble breaking down the function of the LEAFY gene to determine the correct answer? 19) D
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Clarify Question What is the key concept addressed by the question? • This question is asking you to identify the function of the CONSTANS protein. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break the CONSTANS gene and seed production into their component pieces to understand how they function. Gather Content What do you already know about the CONSTANS gene? What other information is related to the question? • The CONSTANS gene links perception of daylength with a signal that results in flowering. • The expression of the CONSTANS gene varies with the time of day, with low expression in the dark and higher expression during the day. • Phytochrome and cryptochrome also regulate CONSTANS expression. • Phytochrome and cryptochrome are red and blue light receptors Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since the CONSTANS gene is involved in flower production as directed by photoperiod, the mutation that is described here will not prevent germination or vegetative growth. This mutation may not even prevent flower production if the plant’s flower production is not linked to daylength. If this is a species that relies on photoperiod for floral development, since CONSTANS function is tied to light receptors, it will Version 1
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not flower. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between normal and mutant forms of the CONSTANS gene, but on your ability to break down the effects of a mutation on plant development. If you got an incorrect answer, did you remember that the CONSTANS gene facilitates flower production, or that the function of this gene is linked to photoperiod? Did you have trouble breaking down the role of the CONSTANS gene to determine the correct answer? 20) D 21) B 22) E 23) A 24) C
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Clarify Question What is the key concept addressed by the question? • This question is asking you to connect the similarities that are present in the parts of a flower. What type of thinking is required? • Apply level: o You are being asked to take what you already know and apply it to the use of the terms that describe flower anatomy. Gather Content What do you already know about flower anatomy? What other information is related to the question? • The corolla is the entire whorl of petals in a flower. • A Calyx is the term for the entire whorl of sepals. • An Androecium is the entire whorl of stamens. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The androecium is the most similar structure to the corolla and calyx, since all three involve smaller structures that are arranged in a whorl. The receptacle is the stem from which the flower parts arise, so that is morphologically very different. Class A genes are only partially responsible for petal production, and since they are genetic rather than morphological, thy are the least related item. Reflect on Process Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use your knowledge of flower structure in a new situation. If you got an incorrect answer, did you remember that sepals, petals, and stamen are arranged in whorls, or that a receptacle is found at the base of a flower? Did you have trouble extending the similarities in the structures of a flower to determine the correct answer? 25) E 26) B 27) D
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Clarify Question What is the key concept addressed by the question? • This question is asking about the effects of a loss-of-function mutation in a CYCLOIDEA-like gene. What type of thinking is required? • Apply level: o You are being asked to take what you already know and apply it to the effects of a mutation in an insect-pollinated plant. Gather Content What do you already know about insects as pollinators? What other information is related to the question? • Insect-mimicking orchids use bilaterally symmetric flowers to mimic the bilateral symmetry of the female bee or wasp. • When the CYCLOIDEA gene mutates, radially symmetrical flowers result. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since the mutant phenotype of CYCLOIDEA is to produce radial flowers, they would no longer resemble the female insect and would fail to be pollinated by the males. • Without the spread of pollen, this mutation would not persist. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: Version 1
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o Answering this question correctly depended on your ability to use the expression of the CYCLOIDEA gene in a new situation. If you got an incorrect answer, did you remember that a mutation in the CYCLOIDEA gene changes the shape of a flower, or that insect-pollinated orchids attract insects by maintaining a specific flower shape? Did you have trouble extending the importance of flower shape to determine the correct answer? 28) B 29) C 30) D 31) D
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Clarify Question What is the key concept addressed by the question? • This question is asking about the cause of different appearances of individuals within a species. What type of thinking is required? • Apply level: o You are being asked to take what you already know and apply it to an explanation of the different morphologies of two plants of the same species. Gather Content What do you already know about dioecious species? What other information is related to the question? • Dioecious means male and females are found as separate individuals.. • Dioecious species may be sexually dimorphic, meaning that males and females have different appearances. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Phase change occurs before flower formation, so that does not account for the different flowers. • Height is not a factor that influences the appearance of flowers. • Sexual dimorphism, or the different appearances of male and female plants of the same species, explains the differences in the plants in this example. Reflect on Process
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the concept of a dioecious species in a new situation. If you got an incorrect answer, did you remember that dioecious species have males and females as separate individuals, or that males and females may look different from one another? Did you have trouble extending the term dioecious to determine the correct answer? 32) A
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Clarify Question What is the key concept addressed by the question? • This question is asking about the adaptiveness of self-pollination in an Artic climate. What type of thinking is required? • Evaluate level: o This question is asking you to evaluate the consequences of a mutation that results in the self-pollination of a plant in the Artic. Gather Content What do you already know about pollination? What other information is related to the question? • Self-pollination is favored in stable, unchanging conditions. • Artic regions would have a minimum of insect pollinators. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Cross-pollination is not required for flower production, so that answer can be excluded. • Self-pollinated plants would be likely to survive and produce offspring, so the self-pollination mutation would be maintained over time. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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• Evaluate level: Answering this question correctly depended on your ability to evaluate the adaptiveness of a mutation that results in self-pollination. If you got an incorrect answer, did you remember that self-pollination differs from cross-pollination by the removal of the need for a pollinator, or the criteria to compare self and cross-pollination includes the availability of potential pollinators? Did you have trouble weighing the merits of selfpollination and cross-pollination to determine the correct answer? 33) B 34) A 35) E 36) D 37) D 38) E 39) E 40) E 41) D 42) D 43) C 44) B
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Clarify Question What is the key concept addressed by the question? • This question is asking you to identify why a holly bush is no longer producing fruit. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break the removal of a holly bush and the following lack of fruit production in a neighboring plant into their component pieces to understand how they function. Gather Content What do you already know about dioecious plants? What other information is related to the question? • Dioecious means male and females are found as separate individuals. • Seeds are produced when male and female gametes are present. • If a plant species has separate male and female individuals, fruit is only produced by female plants. • Fruit is produced to encase seeds and to encourage their dispersal. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Roses do not compete with holly bushes for pollinators. • Roses do not produce inhibitors. • The neighboring holly plant must be female, as it was able to produce fruit. The holly plant that was removed must have been male, as it never produced fruit. Additionally, when the male plant was removed, the female plant stopped producing fruit.
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between monoecious and dioecious plants, but on your ability to analyze what is necessary for fruit production. If you got an incorrect answer, did you remember that components of dioecious plants include separate male and female individuals, or that if one gender is absent, fruit is not produced by dioecious plants? Did you have trouble breaking down dioecious plants and fruit production to determine the correct answer? 45) D 46) C 47) C 48) B 49) C 50) D
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Clarify Question What is the key concept addressed by the question? • This question is asking you to explain the triploid nature of popcorn. What type of thinking is required? • Analyze level: o This question is asking you to identify key factors that qualify something as triploid. Gather Content What do you already know about seed structure? What other information is related to the question? • Triploid cells have three sets of chromosomes. • Popcorn endosperm is triploid, and forms from the fusion of one sperm cell and two polar nuclei in the embryo sac of a plant seed. • The endosperm is the food supply of an embryo. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Popcorn is naturally triploid; it is not modified by agricultural companies or by the butter that is put on the popcorn. Other species of corn also have endosperm that is triploid, so that answer can be excluded. In fact corn typically has starchy, triploid endosperm components that serve as a food source for the embryo. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between the causes of triploidy, but on your ability to analyze, the reasons that popcorn is triploid. If you got an incorrect answer, did you remember that causes of triploidy include the mechanism of endosperm formation, or that corn in general has triploid endosperm? Did you have trouble breaking down triploidy in corn to determine the correct answer? 51) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about the effect of missing sperm in a pollen grain. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break the function of sperm in a pollen grain and their role in the development of a plant embryo into their component pieces to understand how they function. Gather Content What do you already know about plant gametes and fertilization? What other information is related to the question? • Two sperm cells are normally carried in a pollen grain. • One of the two sperm cells fuses with two polar nuclei in the embryo sac of a plant seed to form the endosperm. • The endosperm is the food supply of an embryo. • The other sperm cell from the pollen grain fuses with the egg cell, which forms a zygote. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The endosperm cannot form without a sperm cell from the pollen grain, and without the endosperm, the embryo would not have a food source. Additionally, the zygote will not form without a sperm cell from the pollen grain. If the pollen grain was missing one of the two necessary sperm cells, the plant embryo could not grow. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between the necessary number of sperm in a pollen grain and the role of those sperm in embryo development, but on your ability to break down, or analyze, the consequences of a lack of sufficient sperm cells in the pollen grain. If you got an incorrect answer, did you remember that the functions of the sperm in the pollen grain include fertilizing the egg as well as facilitating the formation of the endosperm as a food source for the embryo? Did you have trouble breaking down the role of sperm cells in embryo development to determine the correct answer? 52) D 53) C 54) E 55) A 56) B 57) A 58) E 59) E
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Clarify Question What is the key concept addressed by the question? • This question is asking about the effects of a mutation in the SHOOTMERISTEMLESS and HOBBIT genes. What type of thinking is required? • Apply level: o You are being asked to take what you already know and apply it to the consequences of gene mutations in a growing plant. Gather Content What do you already know about meristems? What other information is related to the question? • The SHOOTMERISTEMLESS gene is responsible for shoot apical meristem formation. • The HOBBIT gene plays a role in causing the formation of the root meristem. • Meristem contains undifferentiated cells that give rise to other structures, and is found in areas of plants where growth can take place. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Leaf primordia and root caps are derived from the root and shoot meristems that are coded for by the mutated genes, so these structures should not be expected to form. • The cotyledons develop as a result of the action of other genes, so they would develop normally.. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the functions of genes in a new situation. If you got an incorrect answer, did you remember that the SHOOTMERISTEMLESS gene gives rise to the shoot apical meristem: the HOBBIT gene plays a role in root meristem formation: or that meristem tissue is the foundation for other structures? Did you have trouble extending the functions of genes to determine the correct answer? 60) A 61) A 62) C 63) E 64) C 65) A 66) C 67) D 68) D 69) C 70) B 71) B 72) B 73) C 74) A 75) C 76) D
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Clarify Question What is the key concept addressed by the question? • This question is asking you to explain why apomixis is both challenging and beneficial in the production of Kentucky Bluegrass.. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break the challenges and opportunities presented by apomixis into their component pieces to understand how they function. Gather Content What do you already know about apomixis? What other information is related to the question? • Apomixis is the process by which an embryo is produced asexually via the cloning of diploid cells. • Embryos produced through apomixis are diploid and are identical to the parent cell. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Apomixis is really the formation of an embryo through mitosis; the process itself forms seeds, not extensions of the existing parent. • The embryos that result from apomixis are diploid, not triploid, so that answer can be excluded. • Embryos formed through apomixis are not pesticide-resistant unless the parent plant is pesticide-resistant. • Apomixis involves the creation of a clone of a parent cell, so the offspring are identical to the parent. Since this is asexual reproduction, Version 1
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hybridizing two different strains would need special techniques, but would result in plants that could be propagated. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between the benefits and challenges of apomixis, but on your ability to analyze the components of apomixis. If you got an incorrect answer, did you remember that components of apomixis include the formation of a diploid embryo, or that the embryo is a clone of the parent? Did you have trouble breaking down the process of apomixis to determine the correct answer? 77) B
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Clarify Question What is the key concept addressed by the question? • This question is asking about the advantages of apomixis, which is a form of asexual reproduction. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break the characteristics of apomixis into their component pieces to understand how they function. . Gather Content What do you already know about apomixis? What other information is related to the question? • Apomixis is asexual reproduction. • Rather than forming gametes through meiosis, in apomixis, clones of diploid cells form the embryo. • Apomixis requires only one parent. • The products of apomixis are seeds. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The process of apomixis is essentially cloning; the offspring would only be herbicide-resistant if the parent cell was herbicide-resistant. • The offspring produced by apomixis would be identical to the parent, so there would not be a diverse variety of plants to attract a diverse variety of pollinators. • Offspring produced by apomixis would be adapted to an environment Version 1
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as their parent was adapted to that environment. • An advantage of apomixis is that in the production of seeds, dispersal is a possibility. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between apomixis and other forms of reproduction, but on your ability to analyze the outcomes of apomixis. If you got an incorrect answer, did you remember that components of apomixis include the production of clones of the parent, or that the seeds that result from apomixis would be available to disperse away from the parent? Did you have trouble breaking down the nature of offspring produced by apomixis to determine the correct answer? 78) D 79) D 80) A
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Clarify Question What is the key concept addressed by the question? • This question is asking you to identify the most cost-effective way to enhance a garden. What type of thinking is required? • Evaluate level: o This question is asking you to evaluate the best way to add flowers to a garden while keeping cost to a minimum. Gather Content What do you already know about annuals and perennials? What other information is related to the question? • Annuals produce showy flowers, but they die after one year. • Biennials do not flower during the first year of their life, and may flower only once in their lifetime. • Herbaceous perennials live for multiple years and can flower every year. • Woody perennials may take longer to mature, but can flower every year after maturation. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since annuals and biennials may flower only one time in their life, although they can be beautiful displays of flowering, they are not costeffective foe a long-term garden. Woody perennials can produce flowers also. However they can take years to mature; they take up more space; and they may require a greater initial investment of money. Herbaceous perennials are a cost-effective choice because they produce flowers the Version 1
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first year they are planted and continue to flower for multiple years. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your evaluation annuals, perennials, and biennials. If you got an incorrect answer, did you remember that annuals and biennials differ from perennials because their lifecycles differ, or the criteria to compare annuals, biennials, and perennials includes the number of seasons that the plants can be expected to exhibit flowering? Did you have trouble weighing the merits of annuals, biennials, and perennials to determine the correct answer? 81) D
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Clarify Question What is the key concept addressed by the question? • This question is asking you to recognize the stages in the lifecycle of a biennial plant. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break biennials and seed production into their component pieces to understand how they function. Gather Content What do you already know about biennials? What other information is related to the question? • Biennials do not flower in the first year of their life. • Flowers are necessary reproductive structures that give rise to seeds. • Biennial plants that are harvested as crops are typically harvested for their leaves and/or their roots, which grow during the first year. • If a biennial plant is harvested during its first year, it will not have produced flowers or seeds. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Trimming roots only removes tissue and possible food storage sites. This would not induce flowering, as the plant must mature before flowering occurs. • Beta-carotene is not a factor in seed development. • The green top of a carrot is not a flowering structure, so it would not contain pollen. Version 1
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• Keeping in mind that carrots are biennials, they would not flower or produce seeds until the second year of their life. If the plants are not removed after the first year and instead are allowed to grow, in the second year of life seeds could be harvested from the flowers that occur at that time. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between growth and flowering, but on your ability to analyze the lifecycle of a biennial. If you got an incorrect answer, did you remember that components of the lifecycle of a biennial include a year of growth before maturation, or that flowering and seed production does not occur until the second year? Did you have trouble breaking down the biennial life cycle to determine the correct answer? 82) C 83) B
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Clarify Question What is the key concept addressed by the question? • The question is asking you about the key factors in germination. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the reason for lack of germination in a group of seeds. Gather Content What do you already know about germination? What other information is related to the question? • Germination is the development of a plant embryo as it gains photosynthetic structures. • Plant embryos obtain nutrition from nutritional reserves in the endosperm before they are capable of photosynthesis. • The suspensor is a link between a plant embryo and the nutritional reserves of the seed. • To undergo photosynthesis, a seedling must produce photosynthetic structures, and it must emerge from the soil. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Monocots do produce one cotyledon, but this is a genetic and structural difference, not a disadvantage. • Suspensors help to nourish embryos, but they do not develop into embryos. • Seeds can germinate within one season, although older seeds can germinate also. Version 1
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• Although some seeds require fire to germinate, this is an exception rather than the rule. • A plant embryo can be sustained for a limited time by the nutrients stored in the seed, but it must quickly establish photosynthetic structures and be exposed to light for its life to continue. If a seed is planted too deeply, it may use up the nutrient reserves in the seed before it emerges from the ground. In that case, it would die from lack nutrition. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the requirements for germination and growth in a new situation. If you got an incorrect answer, did you remember that germination is fueled by nutrient reserves in the seed? Did you recall that these reserves are used up quickly, and that the plant must undergo photosynthesis after the reserves are gone? Did you have trouble extending the nature of germination to determine the correct answer? 84) B 85) D
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Clarify Question What is the key concept addressed by the question? • This question is asking about the conditions that are necessary for long-term seed dormancy. What type of thinking is required? • Evaluate level: o This question is asking you to evaluate the environment that would be most favorable seed dormancy. Gather Content What do you already know about germination? What other information is related to the question? • To germinate, a seed must absorb water and oxygen. • Oxygen is used in the process of cellular respiration, by which the embryo could obtain energy from nutrients stored within the seed. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Peat is anaerobic and acidic, which would destroy seeds. • The Burgess Shale is a fossilized mass that would not contain living things. • Wax-sealed jars would prevent mold formation and would be a favorable environment for the long-term storage of seeds. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to evaluate the conditions necessary for seed dormancy and long-term survival. If you got an incorrect answer, did you remember that water is one of the factors that causes seeds to germinate, or the criteria to compare dormancy and long-term survival includes protection from environmental conditions? Did you have trouble weighing the merits of the necessary conditions for dormancy to determine the correct answer? 86) A
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Clarify Question What is the key concept addressed by the question? ● Can you identify a type of plant reproduction? What type of thinking is required? ● You are being asked to take what you already know about plant reproduction and use, or apply, it to the reproduction of a spider plant. Gather Content What do you already know about plant reproduction? What other information is related to the question? ● Sexual reproduction of a flowering plant involves pollination and double fertilization. ● In pollination, a male gametophyte from is transferred from a stamen to a stigma. In self-pollinating plants, these flowers can be on the same plant. ● In double fertilization, a pollen produces two sperm which travel down a pollen tube from a stigma to an ovule. One sperm fertilizes an egg, while the other joins with polar nuclei to form endosperm. The ovule then forms a seed, from which the embryo will grow into a new plant. ● Apomixis is a form of asexual reproduction in which an embryo develops in a seed from mitosis instead of from the combination of sperm and egg. ● In vegetative reproduction, asexual reproduction of new plants from shoots or roots give rise to individual clones. ● Protoplast regeneration is a method uses to clone plant cells involving stripping away the cell wall from a protoplast, which can then be induced to undergo mitosis to produce a callus. Choose Answer Given what you now know, what information is most likely to produce the correct answer? Version 1
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● The reproduction described here involves one plant with no discussion of flowers or seeds. ● The growing of spiderettes directly from the stolon is an example of vegetative growth. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use knowledge of plant reproduction in a new situation. If you got an incorrect answer, did you remember that sexual reproduction in flowering plants involves flowers, or that apomixis involves seeds? Did you have trouble extending definitions of the various types of growth to the description of spider plants to determine the correct answer? 87) A
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Clarify Question What is the key concept addressed by the question? ● Can you identify an event in an angiosperm life cycle? What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to identify an event in an angiosperm life cycle. Gather Content What do you already know about the angiosperm life cycle? What other information is related to the question? ● Angiosperms follow a haplodiplontic life cycle, where multicellular diploid sporophytes make spores which grow into multicellular haploid gametophytes that make gametes. ● In angiosperms, the microgametophyte is a pollen grain and the megagametophyte is an embryo sac. ● The microgametophyte is two cells in size. A tube cell makes a pollen tube and a generative cell makes two sperm. Since the gametophyte and gametes are haploid, these cells are made by mitosis. ● The megagametophyte has eight nuclei (one egg, two synergids, three antipodals, and two polar nuclei). Since the gametophyte and gametes are haploid, these cells are made by mitosis. ● In pollination, the microgametophyte travels from the anther to a stigma, where it germinates to make sperm and pollen tube. ● In double fertilization, the two sperm made by the microgametophyte travel down the pollen tube. One fuses with the egg to form a zygote, and the second fuses with the polar nuclei to form endosperm. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Megagametophytes make eggs by mitosis. Reflect on Process Did your problem-solving process lead you to the Version 1
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correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use knowledge of plant life cycles in a new situation. If you got an incorrect answer, did you remember that gametophytes are different from gametes, or that gametophytes make gametes by mitosis? Did you have trouble differentiating between microgametophytes and megagametophytes to determine the correct answer? 88) A
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Clarify Question What is the key concept addressed by the question? ● Can you recognize a stage of flowering? What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to identify the process affected by gibberellic acid. Gather Content What do you already know about the events surrounding flowering? What other information is related to the question? ● Flowers are reproductive organs of angiosperms. ● Seedlings are incapable of producing flowers until they have gone through phase change. ● Floral determination marks the point at which shoots become committed to making flowers. ● Pollination (transfer of male gametophyte from anther to stigma) and double fertilization (delivery of sperm from the pollen to egg and polar nuclei of the embryo sac) both occur after flowers are fully formed. ● Meiosis is a general form by which sporophytes make spores in the plant life cycle. This also occurs after the flowers (which are sporophyte tissue) are formed. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● In this case, the gibberellic acid is inhibiting the formation of flowers only before the flower starts to form. Since the trees have previously born fruit (thus made flowers in the past) the process being blocked is floral determination. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use knowledge of events in flowering in a new situation. If you got an incorrect answer, did you remember the difference between phase change and floral determination, or that gibberellic acid no longer inhibited once the flower started to form? Did you have trouble extending the described effect of gibberellic acid to determine the correct answer? 89) A
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Clarify Question What is the key concept addressed by the question? ● What types of floral identify genes would be expressed in a staminate flower? What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to the development of a staminate flower in corn. Gather Content What do you already know about floral organ identity genes? What other information is related to the question? ● The ABC model proposes that three classes of organ identify genes (A, B, and C) specify the floral organs in the four floral whorls. ● Class A genes alone specify sepals. ● Class A and B genes together specify petals. ● Class B and C genes together specify stamens. ● Class C genes alone specify carpels. ● Class D genes are essential for carpel formation. ● Class E genes are essential for forming any floral part (as opposed to leaves). Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● Since corn tassels are staminate flowers, we should expect them to express B, C, and E floral organ identify genes. Therefore, ZAP1, a class A gene, would not be expressed in tassels. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to use Version 1
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knowledge of floral organ identity genes a new situation. If you got an incorrect answer, did you remember that the ABC model predicts that class B and C genes specify stamens, or that further findings indicate that class E genes will be expressed in all floral organs? Did you have trouble extending the ABCDE model to the specific genes in the question to determine the correct answer? 90) Section Break 90.1) A 90.2) C 90.3) B 90.4) E
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Chapter 41 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) Muscles can carry out their unique motor function because they are the only cells which contain actin and myosin. ⊚ ⊚
2)
true false
True or false: The axon of a neuron can only communicate with other neuronal cells. ⊚ ⊚
true false
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 3) To diagnose and treat a disease, a doctor must evaluate the patient’s body at multiple levels of organization. Identify the level of organization relevant to each stage of the process described below. 1.As part of Fred’s annual physical, the doctor examined his skin, fingernails and hair for signs of disease. Noticing an unusual lesion on his neck, the doctor referred Fred to a dermatologist. 2.Upon observing the lesion, the dermatologist said, “Yes, this looks like it could be a squamous cell carcinoma, a tumor in the epidermis of the skin.” 3.The dermatologist carefully examined all of Fred’s skin for signs of additional tumors, but did not find any. 4.The dermatologist removed the lesion and sent it for a biopsy. Under the microscope, the pathologist saw some cells with abnormal morphology and confirmed a diagnosis of squamous cell carcinoma. However, he noted that the margins of the lesion were clear of abnormal cells, and the tumor had been successfully removed. A) organism, cell,tissue, organ B) organ system,tissue, organ, cell C) organ system,organ, tissue, cell D) organism, cell,organ system, tissue
4)
Which of the following is not a level of organization in the vertebrate body?
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A) cells B) bones C) tissues D) organs E) organ systems
5) It’s the ninth inning, and the bases are loaded. As the pitcher winds up to throw the ball, how does each tissue in his arm contribute to this critical pitch? The_________blank of his fingers grips the ball. His_________blank sends instructions that trigger his_________blank to contract. His_________blank provides stability and transmits the force produced. A) ectoderm;ectoderm; mesoderm; endoderm B) connective tissue; nerve tissue; muscle tissue; epithelial tissue C) epithelium;ectoderm; mesoderm; endoderm D) epithelial tissue; nerve tissue; muscle tissue; connective tissue
6)
If at the last minute the pitcher decides to throw a curveball, which tissue responds first? A) epithelialtissue B) ectoderm C) nerve tissue D) muscle tissue
7) In adult vertebrates, which of these is not one of the four principal kinds of primary tissues? A) epithelial B) connective C) supportive D) muscle E) nerve
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8)
Which of the following are the fundamental embryonic tissues called the "germ layers"? A) tissues, organs,and organ systems B) mesoderm, muscle, and tissue C) ectoderm, endoderm, and exoskeleton D) mesoderm, endoderm, and ectoderm E) mesoderm, exoderm, and hydroderm
9)
Why are epithelial membranes not very thick?
A) Epithelial tissuesare required to support other cells growing on top of the tissue. B) Epithelial tissuesplay a critical role in transport, and must be thin to allow diffusion tooccur. C) Epithelial tissuescan only reach a certain thickness because their growth is constrained bymicrotubules inside the cell membrane. D) Thick epithelialtissues would collapse due to the drying effect of the environment. E) Epithelial tissuesare programmed to stop dividing after only a few cell cycles.
10)
What are epithelial cells with a flat, irregular shape and tapered edges called? A) columnar B) pseudostratified C) squamous D) cuboidal E) stratified
11) Which of the following types of epithelia would be likely to make up the tubules of the kidney?
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A) cuboidal B) squamous C) columnar andsquamous D) columnar E) pseudostratified
12)
Which type of cells line the lungs and blood vessels? A) simple squamous epithelium B) simple cuboidal epithelium C) simple columnar epithelium D) stratified squamous epithelium E) keratinized squamous epithelium
13) Goblet cell hyperplasia is associated with asthma. Based on their function, what is the likely outcome of an overabundance of goblet cells? A) decreased mucusproduction B) excess mucusproduction C) excessO2 absorption D) decreasedCO2 absorption
14) A recent study suggests the surprising idea that intestinal goblet cells present food antigens to dendritic cells to induce tolerance to food molecules. Thus, goblet cell dysfunction may be a cause of food allergies. If this is true, it illustrates the importance of coordination between which two organ systems? A) immune system andcirculatory system B) circulatory systemand endocrine system C) digestive systemand endocrine system D) digestive systemand immune system
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15)
The glands of vertebrates are derived from_________blank epithelium. A) invaginated B) stratified C) endocrine D) scarified E) keratinized
16) If the connection between a gland and the epithelial membrane is maintained as a duct, the gland is called a(n)_________blank gland. A) exocrine B) endocrine C) lymph D) sebaceous E) adrenal
17)
Which of the following would not provide protection to the epidermis? A) keratinized epithelium B) simple squamous epithelium C) stratified squamous epithelium D) layers of dead squamous cells
18)
Which of the following epithelial tissues secretes mucous and is dense with cilia? A) cuboidal B) squamous C) simple D) stratified E) pseudostratified columnar
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19) A friend asks you how exocrine glands differ from endocrine glands. She knows that both form from invaginated epithelium. How do you respond? A) Exocrine and endocrine glands are essentially the same, both produce products that are secreted to the skin's surface. B) Exocrine glands produce hormones which enter the blood stream, while endocrine glands secrete sweat and oil directly to the surface of the skin. C) Endocrine glands produce hormones which enter the blood stream, while exocrine glands secrete sweat and oil directly to the surface of the skin. D) Exocrine glands are found in the thoracic cavity while endocrine glands are located in the pleural cavity. E) The liver is anendocrine gland that secretes directly into epithelial tissues. The pituitarygland is an exocrine gland that secretes into the blood stream.
20) Connective tissue includes adipose tissue, tendons, bone, cartilage, and blood. What do all these tissues have in common? A) They all consistof few cells sparsely distributed in large amounts of extracellularmaterial. B) They all providestructural support to the body. C) They are all hardtissues. D) They allphysically bind other tissues together.
21) The most abundant protein in mammals is collagen. This strong, ropelike molecule is particularly abundant in which tissue? A) heart muscle B) spinal cord C) ligaments D) skeletalmuscle
22) When collagen is hydrolyzed it forms gelatin, the main ingredient of a jiggly dessert adored by children. What parts of a cow provide a rich source of collagen? Version 1
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A) heart and other muscles B) brain C) glandularorgans D) skin, tendons, andcartilage
23) You are researching a family with a heritable disease whose symptoms include hyperflexible joints, pliable skin, stretchy ligaments, and fragile muscles that tear easily. You plan to use genetic testing to determine the cause of the disease. Which gene do you sequence first? A) actin B) epidermal growthfactor C) myosin II heavychain D) collagen
24) All connective tissues share which of the following structural features? I-contain cells II-contain a matrix filled with extracellular material III-contain sarcomere units A) I and III B) II only C) II and III D) I, II, and II E) I and II
25)
In humans, which of these structures is not made of cartilage? A) tip of the nose B) outer ear C) intervertebral disks of the backbone D) knee cap E) larynx
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26)
Which of these is not part of loose connective tissue? A) collagen B) elastin C) reticulin D) chondroitin E) adipose cells
27) Your professor asks you to explain the difference between a tendon and a ligament. How do you answer? A) Tendons securemuscles to other muscles and ligaments secure bones to other bones. B) Tendons andligaments have the same function but are found in different areas of thebody. C) Tendons secure muscles to bones and ligaments secure muscles to other muscles. D) Tendons are just enlarged ligaments. E) Tendons secure muscles to bones and ligaments secure bones to other bones.
28)
What tissue type produces the tough coverings that package organs? A) loose connectivetissue B) dense irregularconnective tissue C) collagen D) dense regularconnective tissue E) adipose
29)
Which connective tissue has a fluid matrix?
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A) adipose B) blood C) cartilage D) dense connective tissue E) loose connective tissue
30)
Which of the following statements about bone and its structure is NOT correct?
A) Bone contains anextracellular matrix of collagen fibers and inorganic calcium phosphatecrystals. B) Bone tissue is notliving because it contains inorganic calcium phosphate crystals. C) Bone tissue is aspecial form of connective tissue. D) Bone tissue servesas a reservoir for calcium and phosphate ions. E) Bone marrow is areservoir for blood stem cells
31) Vertebrate locomotion results from the contraction of muscles anchored to what other tissue? A) bone B) an exoskeleton C) each other D) nerves E) the plasmamembrane
32)
Of which material is cartilage composed? A) glycoproteins andcalcium phosphate B) glycoproteins andcollagen fibers C) collagen fibersand osteocytes D) osteocytes andglycoproteins E) osteocytes andcalcium phosphate
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33) Which is another name for bone cells that remain alive even after the extracellular matrix becomes hardened with calcium phosphate crystals? A) osteocytes B) erythrocytes C) leukocytes D) fibrocytes E) chondrocytes
34) A patient has a disease with symptoms in the outer ear, nose, trachea and spine. Which cells are most likely to have a problem? A) leukocytes B) erythrocytes C) chondrocytes D) osteocytes E) fibroblasts
35)
Which is NOT a cell or fiber type found in loose connective tissues? A) macrophages B) mast cells C) adipose cells D) collagenfibers E) chondrocytes
36) The characteristic that makes the muscle cells unique is the relative abundance and organization of
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A) collagen fibers. B) gelatinous mass. C) actin and myosin fibers. D) keratin fibers. E) fibroblast cells.
37) unit?
What feature of cardiac muscle helps the cells coordinate their contraction as a single
A) fused cells withmultiple nuclei B) covalent bonds between actin and myosin molecules C) intercalateddisks rich in gap junctions D) large numbers ofmotor neurons
38) A scientist is trying to coax stem cells to differentiate into muscle to use as a therapy for muscular dystrophy. He looks at his Petri dish and is excited to see the cells contracting! The cells appear striated and multinucleate. What type of muscle are they? A) cardiacmuscle B) smooth muscle C) involuntarymuscle D) skeletalmuscle
39) Which term refers to muscles that are attached to bones, and cause bones to move at their joints when they contract? A) smooth muscles B) skeletalmuscles C) cardiacmuscles D) ligamenttissues E) involuntarymuscles
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40)
Which of the following types of muscles are striated? A) skeletal and smooth B) cardiac only C) triceps and bicepsonly D) skeletal and cardiac E) skeletal, smooth, and cardiac
41)
Which muscle contraction is involuntary? A) cardiac only B) smooth only C) cardiac and smooth D) skeletal only E) cardiac, smooth, and skeletal
42) The cell body of a motor neuron resides in the spinal cord, but it may control muscles a long distance away. In a giraffe, the ________ of a leg motor neuron may be six feet long! A) dendrite B) soma C) axon D) node ofRanvier
43) What are the cells that are specialized to produce and conduct electrochemical impulses called? A) neurons B) dendrites C) axons D) fibroblasts E) astrocytes
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44)
Where is the nucleus of a neuron found? A) axon branches B) companioncell C) cell body D) dendrites E) myelin sheath
45) In your Ph.D. research, you use thin slices of brain tissue to study neuronal signaling. You attach an electrode to a single neuron, but cannot detect any activity. What is the most likely explanation? A) When you sliced the brain, you disconnected the cell from its dendrites. B) Neurons are notelectrically active -- you should be recording neuroglia instead. C) When you sliced the brain, you disconnected the cell from its neuroglia. D) Excessivemyelination is blocking inputs to the cell.
46)
What structure do myelin sheaths form along? A) axons B) dendrites C) neuroglia D) cell bodies E) ganglia
47) A recovering stroke patient complained about strange smells in his room, but no cause could be found. The doctor diagnosed this as phantosmia, or olfactory hallucination, and said it was likely due to stroke-related damage to which tissue?
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A) nervous system B) olfactoryreceptors C) sensory systems D) nodes ofRanvier
48) Controversy surrounds the use of zinc-containing nasal sprays as a cold remedy, since they have been associated with anosmia (loss of smell). If true, this is likely due to the sprays damaging which tissue? A) nervous system B) osmic nerve C) sensory systems D) neuroglialsystem
49) When we watch Olympic athletes perform, we are admiring the expert control of which systems working together? A) skeletal,endocrine, and circulatory systems B) nervous,circulatory, and skeletal systems C) muscular,integumentary, and circulatory systems D) nervous,muscular, and skeletal systems
50) A bride-to-be is enjoying a manicure and a facial before her hair is styled for the wedding. What organ system is being pampered? A) lymphaticsystem B) integumentarysystem C) endocrinesystem D) digestivesystem
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51) Which of the following systems is NOT directly involved with regulation and maintenance of the body's chemistry? A) the digestive system B) the circulatory system C) the respiratory system D) the urinarysystem E) the reproductivesystem
52)
Which of the following is most likely to function as a defense system? A) the integumentary system B) the musculoskeletal system C) the endocrine system D) the sensory system E) the nervous system
53) A couple is having difficulty conceiving a child, and they decide to see a fertility specialist. Which two organ systems will the specialist examine in this couple? A) reproductive andnervous systems B) endocrine andurinary systems C) reproductive andendocrine systems D) reproductive andurinary systems
54)
Damage to the integument may trigger action by cells of which system? A) reproductivesystem B) immune system C) endocrinesystem D) muscularsystem
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55) Homeostasis is maintained using negative feedback loops. Which part of a negative feedback loop detects conditions? A) response B) effector C) sensor D) integrating center E) stimulus
56) Low body temperature triggers adaptive responses to conserve heat. Once the integrating center detects that body temperature has risen, it will decrease these responses. What does this exemplify? A) adaptation B) negativefeedback C) positivefeedback D) acclimatization
57) Due to a mutation in a smooth muscle gene, the blood vessels in the skin of a certain strain of mouse become dilated when temperature falls below a certain point. Based on the likely outcome of this mutation, what precautions should the researchers take to maintain the health of their mice? A) The mouse roomshould be maintained at a cooler than normal temperature. B) The mouse roomshould be consistently maintained at a warm temperature. C) The mice willhave weak muscles, and should be provided with exercise wheels. D) The mice will besusceptible to high blood pressure, and should not be provided with exercisewheels.
58) Which statement describes a home heating and cooling system that functions in a homeostatic way?
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A) The temperaturealways stays the same. B) The heater nevercomes on. C) The heater is onat a constant rate. D) The thermostatkeeps the temperature within a narrow range.
59) Mechanisms that help generate heat and those that allow release of heat are an example of_________blank. Collectively, these mechanisms increase the_________blank of body temperature. A) endothermicregulation; flexibility B) poikilothermicregulation; stability C) ectothermicregulation; flexibility D) antagonisteffectors; stability
60) Why do some bread recipes suggest letting the dough rise in a warm place after kneading? A) Warming the breadslightly before cooking it in a hot oven stretches out the gluten. B) The metabolicrate of yeast speeds up at warmer temperatures, so more carbon dioxide isreleased and the dough rises more quickly. C) The metabolicrate of yeast slows down at warmer temperatures, so more sugar is maintainedand the bread is sweeter. D) Yeast cannotcarry out fermentation at room temperature.
61)
What is the approximate Q10 value for most enzymes? A) 0.2 B) 2 C) 5 D) 10 E) 20
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62) Some animals allow their body temperature to conform to the environment. What is the old term for these animals, and what is the newer preferred term? A) heterotherms;homeotherms B) homeotherms;endotherms C) isotherms;poikilotherms D) poikilotherms;ectotherms E) endotherms; homeostasis
63)
Which of these is not a method used by ectotherms to affect body temperature? A) countercurrent heat exchange B) basking in the sun C) shivering D) dilation or contraction of blood vessels E) increasing metabolic rate
64) Dogs use panting to dissipate excess heat. What part of their brain detects the need for this response and sends the signal to pant? A) hippocampus B) prefrontalcortex C) amygdala D) hypothalamus
65) When a dog's brain detects the need to dissipate excess heat and the dog begins to pant, the brain acts as the_________blank, and the panting behavior acts as the_________blank. A) stimulator;effector B) integratingcenter; sensor C) integratingcenter; effector D) sensor;integrating center
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66) After yet another patron dripped sweat on her desk, the clerk at the gym complained, “It’s gross working at a gym, with everyone sweating all the time.” “Yes,” the manager replied, “and it’s probably costing us more for_________blank, but I’ll bet we’re saving on_________blank.” A) towels;heating B) weight machines;treadmills C) the water cooler;air conditioning D) the water cooler;towels
67) If a mammal suffered damage to the temperature sensor in its brain, what would be the result? A) The integratingcenter would not receive inputs to compare to the set point. Body temperaturecould rise or fall to dangerous levels. B) Only theintegumentary system is required to sense temperature changes. Body temperaturewould remain stable. C) The animal wouldhave to rely on shivering instead of vasoconstriction to maintain bodyheat. D) The animal wouldfall back onto a more primitive ectothermic mode of regulation.
68) You are an engineer at a power plant that creates large volumes of hot waste water, which disrupts the ecosystem of the river it drains into. Another part of the plant requires warm oil, and the plant uses large amounts of energy to heat it. Inspired by countercurrent exchange in whales, you save energy and benefit the environment by A) running the oilpipes under the river after dumping in the hot waste water B) running the oilpipes around the waste water pipes, to allow heat transfer from water tooil C) running the wastewater and oil through a single pipe D) adding a sensor,integrating center and effectors to control temperature in both pipes
69)
Which of these methods of heat transfer is not relevant to biological systems?
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A) radiation B) conduction C) convection D) evaporation E) reflection
70) Thermoregulation depends on monitoring of blood temperature. What structure acts as the mammalian temperature sensor? A) hypothalamus B) peripheral bloodvessels C) adrenalmedulla D) anterior pituitarygland E) thyroid
71) If the set point of the hypothalamus were to suddenly rise to 40°C (as in the induction phase of a fever), what would the initial response of the body be? A) glands release sweat B) muscles contractto cause shivering C) nothing D) body temperature drops E) blood vessels dilate
72) Which of these thermoregulation processes can be sustained for the longest period of time? A) shivering B) sweating C) nonshivering thermogenesis D) hibernation E) fever
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73)
Which of these factors would have the least effect on heat transfer processes in animals? A) surface area of the body B) difference between body temperature and ambient temperature C) internal insulation such as blubber D) external insulation such as feathers or fur E) bone density
74)
Which of these animals has the highest metabolic rate per unit body mass? A) shrew B) horse C) cat D) human E) elephant
75) Which cells aid in the operation of the nervous system but are unable to conduct nerve impulses? A) neurons B) intercalated disk C) goblet cells D) neuroglia
SECTION BREAK. Answer all the part questions. 76) Match the letter of each example from childbirth to the appropriate component of a positive feedback loop. A.pituitary gland secretes oxytocin, which acts on the uterus B.uterine contractions increase C.fetus is pushed against uterine opening D.receptors detect stretch E.brain receives and compares stretch information
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76.1)
Effector
76.2)
Integrating Center
76.3)
Response
76.4)
Stimulus
77) Adult giraffes can be up to 20 ft. tall, and thus require special adaptations to maintain appropriate blood pressure. One adaptation is the rete mirabile, a group of blood vessels that form a web or net-like structure to slow blood flow.
77.1) The giraffe, as the tallest living land animal, has several adaptations for its height. To prevent blood from pooling in the head when it bends down to drink, the jugular veins of a giraffe have multiple one-way valves. Furthermore, a web of arteries and veins in the neck called the rete mirabile (“wonderful net”) slows the flow of blood into the brain. These specializations of the_________blank act as mechanisms to maintain_________blank. A) nervous system;homeothermy B) nervous system;temperature homeostasis C) circulatorysystem; blood pressure homeostasis D) circulatorysystem; pH homeostasis
77.2) Although especially useful to the giraffe, the rete mirabile is similar to a countercurrent heat exchange system in other related, less evolved, mammals. Thus a mechanism for _________blank homeostasis is likely to have evolved from a mechanism previously used for _________blank homeostasis.
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A) blood pressure; pH B) temperature; blood pressure C) blood pressure; temperature D) pH; blood pressure
78) Shivering is used by mammals to increase body heat when the hypothalamus detects a body temperature below the set point. Although the behavior involves muscles, the outcome is not movement but "wasted" energy in the form of heat. This is an example of nature reusing a body structure for an additional purpose.
78.1) A scout troop sets out on a backpacking trip. Soon, an unexpected storm gets them drenched, and the troop leaders discover that few boys have packed warm clothes. Several scouts start shivering uncontrollably, a sign of hypothermia. The leaders call off the trip and the group heads back to their cars. This shivering response was A) an attempt to produce heat by burning large amounts of ATP. B) a maladaptive response that wastes energy. C) an attempt to produce heat by creating friction with their clothing. D) a social signal that evolved to alert adults to take action.
78.2) If the boys progressed into full-blown hypothermia, this would be a failure of which regulatory system? A) endodermicregulation B) temperaturehomeostasis C) ectothermicregulation D) glucosehomeostasis
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Answer Key Test name: Chap 41_13e_Raven 1) FALSE 2) FALSE 3) B
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Clarify Question ● What is the key concept addressed by the question?● The concept addressed here is the categorization of vertebrate structure into one of four levels of organization. ● What type of thinking is required?● Analyze level:● This question is asking you to identify key factors that qualify something as a cell, tissue, organ, or organ system. Gather Content ● What do you already know about biological levels of organization? What other information is related to the question?● Biologists divide the vertebrate body into four levels of organization. ● The levels of organization are cells, tissues, organs, and organ systems. ● Cells are small units of life that in eukaryotes (including vertebrates) possess a nucleus and organelles. ● Tissues are composed of cells with similar structure and function. ● Vertebrates have four tissue types: epithelial, connective, muscular, and nervous tissue. ● Organs are functional units that are composed of multiple tissue types. ● Organ systems are groups of organs that function together. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● In scenario 1, the doctor is examining organs such as the fingernails, nails, and hair within the larger organ system, which in this case is the integumentary system. This scenario is an examination of an organ system. ● Scenario 2 involves an examination of a possible squamous cell Version 1
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carcinoma, which are tissue-level with the vertebrate organizational scheme. ● The doctor is examining Fred’s skin in Scenario 3. Skin is an organ. ● In scenario 4, the pathologist is using a microscope to examine cells. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Analyze level:● Answering this question correctly depended not only on distinguishing between the levels of organization in the vertebrate body, but on your ability to break down, or analyze, specific examples of each level. If you got an incorrect answer, did you remember that the skin is an organ, or that the skin, along with the nails and hair, fall into the category of organ system? Did you have trouble breaking down the levels of organization to determine the correct answer? 4) B 5) D 6) C
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Clarify Question ● What is the key concept addressed by the question?● The concept addressed here is the identification of the tissue that would facilitate a last-minute response. ● What type of thinking is required?● Analyze level:● This question is asking you to identify key factors that qualify something as one of the tissues of the vertebrate body. Gather Content ● What do you already know about the tissues of the vertebrate body? What other information is related to the question?● Vertebrates have four tissue types: epithelial, connective, muscular, and nervous tissue. ● Epithelial tissue covers or lines. For example, the skin is epithelial tissue, as is the lining of the gut and the lining of the blood vessels. Glands are modified epithelia. ● Connective tissue includes blood, fat, bone, and cartilage. ● Muscle tissue includes smooth muscle, skeletal muscle, and cardiac muscle. ● Nervous tissue includes the brain, spinal cord, and nerves. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● Ectoderm is a germ layer, not a tissue. ● Epithelial tissue is exemplified here by the skin, but the skin is not involved in generating the last-minute idea. ● Muscle tissue is also involved here, but it is involved in carrying out the response, not in the initial formulation of the idea. ● The tissue that would respond first would be the tissue that originates the action. The thought would have originated in the brain, which is Version 1
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nervous tissue. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Analyze level:● Answering this question correctly depended not only on distinguishing between germ layers and tissues, but on your ability to break down, or analyze, the individual tissue types. If you got an incorrect answer, did you remember that components of response include nervous stimulation for the action to be initiated, or that the brain is nervous tissue? Did you have trouble breaking down the types of tissue to determine the correct answer? 7) C 8) D 9) B 10) C 11) A 12) A 13) B
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the consequences of a greater than normal number of goblet cells. ● What type of thinking is required?● Apply level:● You are being asked to take what you already know and use, or apply, it to the excessive production of goblet cells. Gather Content ● What do you already know about goblet cells? What other information is related to the question?● Goblet cells are named in accordance with their goblet-like shape. ● Goblet cell locations include mucous membranes. ● Goblet cells are known to produce mucus. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● If a greater than expected number of goblet cells are present, it stands to reason that an excessive amount of their secretion, mucus, would also be present. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level:● Answering this question correctly depended on your ability to use goblet cells in a new situation. If you got an incorrect answer, did you remember that goblet cells produce mucus? Did you have trouble extending goblet cells to determine the correct answer?
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14) D
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Clarify Question ● What is the key concept addressed by the question?● The concept addressed here is the relationship between two systems of the body. ● What type of thinking is required?● Analyze level● This is an analyze question because you have to break dendritic cells and goblet cells into their component pieces to understand how they function. Gather Content ● What do you already know about goblet cells and dendritic cells? What other information is related to the question?● Dendritic cells are antigen-presenting cells of the immune system. They are also called accessory cells. ● Dendritic cells present antigens to T cells, so an immune response can be formulated against the antigen. ● Goblet cells are found within the mucous membranes of the digestive tract, among other places. ● Goblet cells are known to produce mucus. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● Neither the endocrine system nor the circulatory system gave rise to the dendritic or goblet cells. ● Since dendritic cells are immune cells, the immune system is at work here. The goblet cells in this example are representatives of the digestive system. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Version 1
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Analyze level:● Answering this question correctly depended not only on distinguishing between dendritic and goblet cells, but on your ability to break down, or analyze, the systems that gave rise to these cells. If you got an incorrect answer, did you remember that components of dendritic cells include immune system functions, or that goblet cells can be components of the digestive tract? Did you have trouble breaking down these cells to determine the correct answer? 15) A 16) A 17) B 18) E 19) C 20) A 21) C 22) D
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the locations in which collagen is found in the body of a cow. ● What type of thinking is required?● Apply level:● You are being asked to take what you already know and use, or apply, it to relating collagen to specific cow parts. Gather Content ● What do you already know about collagen? What other information is related to the question?● Collagen is a protein that can be very strong, especially when fibers are concentrated in one location. ● Collagen is found in dense connective tissue in the vertebrate body. ● Collagen functions as a component of the skin, organ coverings, as the covering nerves, muscle, and bone, and it is found within cartilage. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● Collagen is not found in abundance within muscle, including heart muscle, glandular organs, and the brain. ● Since collagen is found in connective tissue, it would be abundant in tendons and cartilage, which are examples of connective tissue. ● The skin also contains collagen, which provides strength to the skin. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level:● Answering this question correctly depended on your ability to use collagen in a new situation. If you got an incorrect answer, did you Version 1
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remember that collagen is present in the skin and in a variety of connective tissues? Did you have trouble extending collagen to determine the correct answer? 23) D
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Clarify Question ● What is the key concept addressed by the question?● The concept addressed here is the identification of a gene product that reinforces tissue. ● What type of thinking is required?● Evaluate level:● This question is asking you to weigh and judge, or evaluate, the gene that is most likely to produce a tissue-strengthening product. Gather Content ● What do you already know about the strengthening of tissues? What other information is related to the question?● A major strengthening component of a variety of different tissues is collagen. ● Collagen is the most common protein in mammals. ● In muscle tissue, although collagen is not especially abundant, it is found in the endomysium that surrounds individual muscle cells. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● Epidermal growth factor does not strengthen tissue, it encourages the growth of tissue. ● Actin and myosin serve in the contraction of muscles. While actin is a component of the cytoskeleton, it does not play a role in strengthening tissue. ● Collagen is the logical choice here, as it is the most abundant protein in mammals, and it is known to strengthen tissue. ● This example is similar to the disease known as Ehlers-Danlos Syndrome, which may be caused by the mutation of one of several collagen genes, or a few related genes. Reflect on Process Version 1
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● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Evaluate level:● Answering this question correctly depended on your ability to weigh and judge, or evaluate, genes and their products as they relate to the strengthening of tissue. If you got an incorrect answer, did you remember that collagen is a protein that strengthens tissue, or that collagen is a component of many different tissues? Did you have trouble weighing the merits of collagen to determine the correct answer? 24) E 25) D 26) D 27) E 28) B 29) B 30) B 31) A 32) B 33) A 34) C 35) E 36) C 37) C 38) D
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Clarify Question ● What is the key concept addressed by the question?● This question is asking you to identify which specific type of muscle is present based on the characteristics of the muscle. ● What type of thinking is required?● Apply level:● You are being asked to take what you already know and use, or apply, it to the specific identification of muscle tissue. Gather Content ● What do you already know about muscle tissue? What other information is related to the question?● Muscle tissue can be divided into three subdivisions; cardiac, skeletal, and smooth muscle. ● Cardiac muscle is striated, involuntary, and tends to have a single nucleus per cell. ● Smooth muscle is not striated, it is involuntary, and smooth muscle cells also tend to have one nucleus per cell. ● Skeletal muscle is striated, voluntary, and each cell has more than one nucleus. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● Involuntary muscle includes cardiac and smooth muscle, and neither is multinucleate. ● Neither smooth muscle nor cardiac muscle is multinucleate. ● Skeletal muscle is the only striated, multinucleate muscle tissue. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply Version 1
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level:● Answering this question correctly depended on your ability to use the types of muscle tissue in a new situation. If you got an incorrect answer, did you remember that skeletal muscle is striated, or that skeletal muscle cells are multinucleate? Did you have trouble extending muscle tissue to determine the correct answer? 39) B 40) D 41) C 42) C 43) A 44) C 45) A
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the nature of the detectable signaling of the brain. ● What type of thinking is required?● Apply level:● You are being asked to take what you already know and use, or apply, it to the passage of signals within the brain. Gather Content ● What do you already know about neuronal signaling? What other information is related to the question?● Neurons are the basic units of nervous tissue. ● A neuron receives messages through its dendrites, passes the message along the cell body, and passes the message along through its axon. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● Neuroglia are support cells for neurons; they do not pass messages along. ● Myelination insulates the axon, it does not block the passage of a signal. ● Since dendrites are the input for a signal, the only correct answer from these choices is that the dendrites were cut, thereby stopping the neuronal signal by severing the inputs to the nerve cell. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level:● Answering this question correctly depended on your ability to use neuronal signaling in a new situation. If you got an incorrect answer, Version 1
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did you remember that dendrites receive neuronal signals, or that axons pass signals along? Did you have trouble extending neuronal signaling to determine the correct answer? 46) A 47) A
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the tissue that is impacted by a stroke. ● What type of thinking is required?● Apply level:● You are being asked to take what you already know and use, or apply, it to the effects of a stroke. Gather Content ● What do you already know about olfaction? What other information is related to the question?● Olfaction, or the sense of smell, is a component of the nervous system. ● Dendrites in the nasal mucosa receive signals in the form of molecules. ● Once a molecule binds with a receptor on a dendrite, a signal is sent to the central nervous system so the molecule can be recognized. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● Damage to olfactory receptors or to peripheral nerves would likely result in lack of olfaction, not abnormal olfaction. ● Since nodes of Ranvier are involved in passing signals along, if they were damaged, it is most likely that olfaction would not occur. ● A stroke is damage to the brain caused by loss of blood flow. ● The recognition of a scent occurs in the brain, so damage to the brain could alter the perception of smell. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result?● Apply level:● Answering this question correctly depended on your ability to use olfaction in a new situation. If you got an incorrect answer, did you remember that scents are received in the nose, but are perceived in the brain? Did you have trouble extending olfaction to determine the correct answer? 48) C
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the difference between receiving olfactory stimuli and perceiving them. ● What type of thinking is required?● Choose from the following samples to streamline your writing:● Apply level:● You are being asked to take what you already know and use, or apply, it to olfaction.
Gather Content ● What do you already know about olfaction? What other information is related to the question?● Olfaction, or the sense of smell, is a component of the nervous system. ● Dendrites in the nasal mucosa receive signals in the form of molecules. ● Once a molecule binds with a receptor on a dendrite, a signal is sent to the central nervous system so the molecule can be recognized. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● The recognition of a scent occurs in the brain, so damage to the central nervous system could alter the perception of smell, but it would not stop the passage of a signal from the nose. ● The neuroglia are support cells for neurons, but they do not receive or perceive sensory input. ● Damage to olfactory receptors or to peripheral nerves would likely result in lack of olfaction. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level:● Answering this question correctly depended on your ability to use olfaction in a new situation. If you got an incorrect answer, did you remember that scents are received in the nose, but are perceived in the brain? Did you have trouble extending olfaction to determine the correct answer? 49) D
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the integration of body systems. ● What type of thinking is required?● Apply level:● You are being asked to take what you already know and use, or apply, it the systems that work together to cause movement. Gather Content ● What do you already know about movement? What other information is related to the question?● To move, a plan must be formulated in the central nervous system. ● Once the plan is formulated, the message must be passed along through nerves to the muscles. ● The move is accomplished by the contractions of muscles, which move the bones of the limbs or trunk. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● While the integumentary, endocrine, and circulatory systems support the health of the body, they do not play a direct role in movement. ● The actions that are required to successfully complete a movement are planned in the brain, and are carried by the nerves to the muscles, which move components of the skeletal system. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level:● Answering this question correctly depended on your ability to Version 1
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use movement in a new situation. If you got an incorrect answer, did you remember that movement is planned in the central nervous system, or that the muscles contract to move the skeletal system? Did you have trouble extending movement to determine the correct answer? 50) B
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Clarify Question ● What is the key concept addressed by the question?● This question is asking you to identify the body system that includes the hair, skin, and nails. ● What type of thinking is required?● Apply level:● You are being asked to take what you already know and use, or apply, it to the identification of the system that includes the hair, skin, and nails. Gather Content ● What do you already know about the skin, hair, and nails? What other information is related to the question?● The hair, skin, and nails all contain living and nonliving tissue. ● The body covering consists of the hair, skin, and nails. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● The digestive system includes the stomach, intestine, pancreas, and liver, but not the skin, nails, or hair. ● The lymphatic system includes vessels, nodes, the spleen, and the thymus, but not the skin, hair, or nails. ● The endocrine system includes the pineal gland, the pituitary gland, and other glands, but not the hair, skin, or nails. ● The integumentary system is the system that contains the hair, skin, and nails. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level:● Answering this question correctly depended on your Version 1
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ability to use the hair, skin, and nails in a new situation. If you got an incorrect answer, did you remember that these structures are components of the integumentary system? Did you have trouble extending these structures to determine the correct answer? 51) E 52) A 53) C
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the systems that play a direct role in fertility. ● What type of thinking is required?● Apply level:● You are being asked to take what you already know and use, or apply, it to body systems that are involved in infertility. Gather Content ● What do you already know about fertility? What other information is related to the question?● The primary organs of the reproductive system, the testes and the ovaries, produce gametes, which are required for the production of offspring. ● The production of gametes is regulated by hormones, which are products of the endocrine system. Choose Answer● Given what you now know, what information is most likely to produce the correct answer?● The endocrine, urinary, and nervous systems do not play a direct role in infertility. ● Since gametes are made by the organs of the reproductive system, and the organs of the reproductive system are controlled by the hormones of the endocrine system, it is the actions of the reproductive system and the endocrine system that are primary causes of infertility. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level:● Answering this question correctly depended on your ability to use fertility in a new situation. If you got an incorrect answer, did you remember that gametes are produced by the primary reproductive Version 1
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organs, or that the hormones of the endocrine system regulate gamete production? Did you have trouble extending fertility to determine the correct answer? 54) B 55) C 56) B 57) B
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the effects of a mutation on the temperature-regulating ability of a mouse. ● What type of thinking is required?● Evaluate level:● This question is asking you to weigh and judge, or evaluate, the consequences of a mutation in the blood vessels of a mouse on the ability of the mouse to maintain a healthy body temperature. Gather Content ● What do you already know about mammalian body temperature? What other information is related to the question?● Mammals maintain a body temperature that stays within a narrow range around a set point. ● For humans, this set point is 98.6F. ● Body temperature in mammals is maintained by a negative feedback loop. ● When body temperature in a mammal begins to deviate from the set point, it is sensed and reported to the central nervous system. ● The central nervous system formulates a response that will bring the body temperature back to the set point. ● Vasoconstriction tightens the blood vessels and brings them toward the core of the body. This conserves body temperature in cold environments. ● Vasodilation widens the blood vessels and moves them closer to the surface of the body. This releases heat to the environment and aids the maintenance of body temperature in warm environments. Choose Answer ● Given what you now know, what information is most likely to Version 1
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produce the correct answer?● Although exercise strengthens skeletal muscles, its effects on the smooth muscle of the blood vessels would not be significant in this example. ● Dilation of blood vessels, regardless of the cause, would lower blood pressure, not raise blood pressure. ● In the mutant mice, body temperature will fall rapidly due to positive feedback from heat loss when blood vessels are dilated, so cold temperatures might lead to hypothermia and must be avoided. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Evaluate level:● Answering this question correctly depended on your ability to weigh and judge, or evaluate, the dilation of blood vessels and the effect on body temperature. If you got an incorrect answer, did you remember that vasodilation releases heat from the body and lowers body temperature, or smooth muscle facilitates this vasodilation? Did you have trouble weighing the merits of blood vessel dilation to determine the correct answer? 58) D 59) D 60) B
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the benefit of a warm temperature to the rising of bread dough. ● What type of thinking is required?● Apply level:● You are being asked to take what you already know and use, or apply, it to the consequences of an increased temperature on the outcome of rising bread dough. Gather Content ● What do you already know about yeast? What other information is related to the question?● Living yeast, a one-celled fungus, is a necessary component of bread dough if the dough is to rise. ● Yeast feed on the sugar in bread dough. ● As the yeast ingest the sugar, they carry out glycolysis and then alcoholic fermentation on the sugar. ● Glycolysis and fermentation are enzyme-driven processes. ● As long as the temperature is not so high that it is damaging to the structure of the enzyme, enzyme activity tends to increase with temperature to a certain point. ● Fermentation produces carbon dioxide, which is released as a gas. ● The gas bubbles of carbon dioxide cause bread dough to rise. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● Yeast can ferment at room temperature, but the rate is much slower than it is at warmer temperatures. ● Metabolism does not decrease with increased temperature unless the temperature is so high that it becomes damaging to enzymes. Version 1
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● If the yeast is kept warm, its enzymes will metabolize the sugar in the bread dough faster, which will cause the bread dough to rise faster. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level:● Answering this question correctly depended on your ability to use the action of yeast in a new situation. If you got an incorrect answer, did you remember that yeast metabolize the sugar in bread dough, or that temperature and the rate of activity for metabolic enzymes increase together? Did you have trouble extending the nature of yeast to determine the correct answer? 61) B 62) D 63) E 64) D 65) C 66) C
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Clarify Question ● What is the key concept addressed by the question?● The concept addressed here is the cost and benefit of sweating. ● What type of thinking is required?● Evaluate level:● This question is asking you to weigh and judge, or evaluate, the effects of sweating. Gather Content ● What do you already know about sweating? What other information is related to the question?● Sweat is mostly water, but also contains salts, ammonia, and other trace compounds. ● Sweating is a process that cools the body, but it must be accommodated by increased water intake. ● Excessive sweating without increased water intake can lead to dehydration. ● As sweat evaporates from the skin, the water that evaporates carries heat along as well. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● Since the patrons are sweating, they are cooling themselves. This might decrease the need for air conditioning, but it would certainly not decrease the need for towels. ● Sweat is mostly water, the production of sweat depletes water in the body. ● With excessive sweating, an increased water intake is necessary, so the need for available water would increase in this example. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result?● Evaluate level:● Answering this question correctly depended on your ability to weigh and judge, or evaluate, sweating and its consequences. If you got an incorrect answer, did you remember that sweating cools the body when the sweat evaporates, or that excessive sweating can lead to dehydration if water intake is not increased? Did you have trouble weighing the merits of sweating relative to water consumption to determine the correct answer? 67) A
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Clarify Question ● What is the key concept addressed by the question?● The question is asking about the effects of the lack of temperature sensing ability in the brain of an animal. ● What type of thinking is required?● Apply level:● You are being asked to take what you already know and use, or apply, it to the loss of temperature-sensing ability. Gather Content ● What do you already know about temperature regulation? What other information is related to the question?● Ectotherms have a body temperature that varies with the environment, while endotherms maintain a constant internal body temperature. ● Mammals are endotherms. ● Body temperature in mammals is maintained by a negative feedback loop. ● When body temperature in a mammal begins to deviate from the setpoint, it is sensed by the integrating center in the central nervous system. ● The central nervous system formulates a response that will bring the body temperature back to the set point. ● Vasoconstriction tightens the blood vessels and brings them toward the core of the body. This conserves body temperature in cold environments. ● Vasodilation widens the blood vessels and moves them closer to the surface of the body. This releases heat to the environment and aids the maintenance of body temperature in warm environments. Choose Answer Version 1
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● Given what you now know, what information is most likely to produce the correct answer?● The nerve endings in the skin, which is a component of the integumentary system, do have the ability to detect temperature changes, but temperature changes are also sensed internally. ● An endothermic animal cannot change into an ectothermic animal. ● Without an integrating center sensor, shivering would not be stimulated. ● Since the temperature sensor, which is a component of the integrating center, is damaged in this example, the central nervous system would not receive inputs to compare to the set point. Consequently, it could not formulate a response to a decreased or increased body temperature, and body temperature could very dangerously. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level:● Answering this question correctly depended on your ability to use body temperature regulation in a new situation. If you got an incorrect answer, did you remember that body temperature regulation in mammals is accomplished through a negative feedback loop, or that the integrating center is a mandatory component of that feedback loop? Did you have trouble extending body temperature regulation to determine the correct answer? 68) B
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Clarify Question ● What is the key concept addressed by the question?● This question is asking how the principle of countercurrent exchange can be used in a non-biological setting. ● What type of thinking is required?● Apply level:● You are being asked to take what you already know and use, or apply, it to the use of countercurrent exchange. Gather Content ● What do you already know about countercurrent exchange? What other information is related to the question?● Countercurrent exchange is seen in many different species, from fish to mammals. ● Countercurrent exchange allows the transfer of heat or a substance from blood moving in one direction to blood that is moving in the opposite direction. ● Efficiency is maximized by the use of countercurrent exchange. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● If the oil and wastewater were traveling in the same pipe, each would become contaminated. ● Running the pipe under the river would not serve any constructive purpose. ● The sensor, integrating center, and effectors are components of feedback loops of living things. While similar items could be utilized here, they do not exemplify countercurrent exchange. ● If the pipe that carries the hot wastewater out of the plant could be placed in close proximity to the pipe that directs the oil that needs to be warmed into the plant, heat would transfer from the hot wastewater pipe Version 1
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to the oil pipe over the entire distance that the two pipes are parallel. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level:● Answering this question correctly depended on your ability to use countercurrent exchange in a new situation. If you got an incorrect answer, did you remember that countercurrent exchange allows heat to be transferred from one vessel to another, or that it maximizes efficiency? Did you have trouble extending countercurrent exchange to determine the correct answer? 69) E 70) A 71) B 72) D 73) E 74) A 75) D 76) Section Break 76.1) A
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the components of a positive feedback loop. ● What type of thinking is required?● Apply level:● You are being asked to take what you already know and use, or apply, it to the positive feedback loop associated with childbirth. Gather Content ● What do you already know about positive feedback? What other information is related to the question?● Positive feedback increases the deviation from a normal value of a variable. ● Positive feedback consists of 4 components; the stimulus, integrating center, effector, and response. ● The stimulus is the starting point for the feedback loop. It is a change to which the body will respond. ● The integrating center receives the stimulus and organizes a response. ● An effector is usually a muscle or a gland that causes the response to occur. ● The response is an increase in the deviation from a normal value. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● The effector in this case is the pituitary gland, because it causes the response to occur. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you Version 1
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astray? How can you revise your approach to produce a more desirable result?● Apply level:● Answering this question correctly depended on your ability to use a positive feedback loop in a new situation. If you got an incorrect answer, did you remember that the pituitary gland causes the response, or that in a positive feedback loop the component that causes a response is known as the effector? Did you have trouble extending a positive feedback loop to determine the correct answer? 76.2) E
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the components of a positive feedback loop. ● What type of thinking is required?● Apply level:● You are being asked to take what you already know and use, or apply, it to the positive feedback loop associated with childbirth. Gather Content ● What do you already know about positive feedback? What other information is related to the question?● Positive feedback increases the deviation from a normal value of a variable. ● Positive feedback consists of 4 components; the stimulus, integrating center, effector, and response. ● The stimulus is the starting point for the feedback loop. It is a change to which the body will respond. ● The integrating center receives the stimulus and organizes a response. ● An effector is usually a muscle or a gland that causes the response to occur. ● The response is an increase in the deviation from a normal value. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● The integrating center in this case is the brain, because it receives and processes information. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you Version 1
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astray? How can you revise your approach to produce a more desirable result?● Apply level:● Answering this question correctly depended on your ability to use a positive feedback loop in a new situation. If you got an incorrect answer, did you remember that the brain processes the information, or that in a positive feedback loop the component that processes information is known as the integrating center? Did you have trouble extending a positive feedback loop to determine the correct answer? 76.3) B
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the components of a positive feedback loop. ● What type of thinking is required?● Apply level:● You are being asked to take what you already know and use, or apply, it to the positive feedback loop associated with childbirth. Gather Content ● What do you already know about positive feedback? What other information is related to the question?● Positive feedback increases the deviation from a normal value of a variable. ● Positive feedback consists of 4 components; the stimulus, integrating center, effector, and response. ● The stimulus is the starting point for the feedback loop. It is a change to which the body will respond. ● The integrating center receives the stimulus and organizes a response. ● An effector is usually a muscle or a gland that causes the response to occur. ● The response is an increase in the deviation from a normal value. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● The response in this case is the uterine contractions, because they increase the deviation from normal. Reflect on Process ● Did your problem-solving process lead you to the correct Version 1
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answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level:● Answering this question correctly depended on your ability to use a positive feedback loop in a new situation. If you got an incorrect answer, did you remember that the uterine contractions increase the deviation from normal, or that in a positive feedback loop the component that increases the deviation from normal is known as the response? Did you have trouble extending a positive feedback loop to determine the correct answer? 76.4) C
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the components of a positive feedback loop. ● What type of thinking is required?● Apply level:● You are being asked to take what you already know and use, or apply, it to the positive feedback loop associated with childbirth. Gather Content ● What do you already know about positive feedback? What other information is related to the question?● Positive feedback increases the deviation from a normal value of a variable. ● Positive feedback consists of 4 components; the stimulus, integrating center, effector, and response. ● The stimulus is the starting point for the feedback loop. It is a change to which the body will respond. ● The integrating center receives the stimulus and organizes a response. ● An effector is usually a muscle or a gland that causes the response to occur. ● The response is an increase in the deviation from a normal value. Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● The stimulus in this case is the pressure against the uterine opening, because it is a change to which the body will respond. Reflect on Process ● Did your problem-solving process lead you to the correct Version 1
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answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level:● Answering this question correctly depended on your ability to use a positive feedback loop in a new situation. If you got an incorrect answer, did you remember that the pressure on the uterine opening is a change to which the body will respond, or that in a positive feedback loop the component that is known as the stimulus? Did you have trouble extending a positive feedback loop to determine the correct answer? 77) Section Break 77.1) C
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the nature of the specialized vascularization of a giraffe. ● What type of thinking is required?● Apply level:● You are being asked to take what you already know and use, or apply, it to the specializations of blood vessels in the giraffe. Gather Content ● What do you already know about blood vessels and valves? What other information is related to the question?● Valves are found between the upper and lower chambers of the mammalian heart, as well as at the exits of the heart and in the larger veins of the body. ● Valves prevent the backflow of blood, and thus heighten the efficiency of the heart and of the transport of blood. ● The pooling of blood that would occur without the presence of valves and other adaptations like the rete mirabile could cause dangerous changes in blood pressure. ● Variables such as blood pressure, heart rate, blood pH, body temperature, and others must be kept within a narrow range to be conducive to maintaining life. ● Different animals have specific conditions they keep in this constant range, for example, mammals keep temperature within a narrow range, but amphibian body temperature varies with the environment. Amphibians keep other variables within a narrow range. ● The maintenance of conditions within a narrow range is called homeostasis. Version 1
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Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● Homeothermy refers to the regulation of body temperature at a set point despite the temperature of the environment. All mammals are homeotherms, so the described adaptations are not things that give rise to homeothermy. ● The nervous system is not playing a direct role in the maintenance of the blood vessels of the giraffe. ● Since the blood vessels are components of the circulatory system, this is a correct choice. Also, since the rete mirabile keep blood pressure from changing rapidly, this is an example of blood pressure homeostasis. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level:● Answering this question correctly depended on your ability to use blood vessels in a new situation. If you got an incorrect answer, did you remember that valves prevent the backflow of blood, or that moving blood in one direction helps to maintain normal conditions within the circulatory system? Did you have trouble extending the nature of the blood vessels to determine the correct answer? 77.2) C
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Clarify Question ● What is the key concept addressed by the question?● This question is asking about the nature of the specialized vascularization of a giraffe. ● What type of thinking is required?● Apply level:● You are being asked to take what you already know and use, or apply, it to the specializations of blood vessels in the giraffe. Gather Content ● What do you already know about the circulatory system? What other information is related to the question?● In the larger veins, valves prevent the backflow of blood, and thus heighten the efficiency of the heart and of the transport of blood. ● The pooling of blood that would occur without the presence of valves and other adaptations like the rete mirabile could cause dangerous changes in blood pressure. ● In addition to its other properties, the blood, specifically the plasma of the blood, helps to stabilize body temperature. ● Variables such as blood pressure, heart rate, blood pH, body temperature, and others must be kept within a narrow range to be conducive to maintaining life. ● Different animals have specific conditions they keep in this constant range, for example, mammals keep temperature within a narrow range, but amphibian body temperature varies with the environment. Amphibians keep other variables within a narrow range. ● The maintenance of conditions within a narrow range is called homeostasis.
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Choose Answer ● Given what you now know, what information is most likely to produce the correct answer?● The pH of the blood would be unaffected by the nature of the rete mirabile. ● The rete mirabile is a structure that is circulatory in nature, and functions to keep blood pressure from changing rapidly. This is an example of blood pressure homeostasis. ● With its similarity to countercurrent exchange, which allows the transfer of heat from blood moving in one direction to the blood that is moving in the opposite direction, the rete mirabile helps to maintain a constant body temperature. Reflect on Process ● Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?● Apply level:● Answering this question correctly depended on your ability to use the blood vessels in a new situation. If you got an incorrect answer, did you remember that the rete mirabile aids blood pressure homeostasis, or that the flow of blood through the rete mirabile would also enhance body temperature regulation? Did you have trouble extending the blood vessels to determine the correct answer? 78) Section Break 78.1) A 78.2) B
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Chapter 42 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) True or false: neurons are the only electrically-active cells. ⊚ ⊚
2)
true false
True or false: When a neuron is not firing, the sodium-potassium pump is inactive. ⊚ ⊚
true false
CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 3) "Synapses are connections between the axon of one neuron and the dendrite of another neuron, where neurotransmitters transmit a chemical signal." How would you modify this statement to make it more complete? (Check all that apply.) A) The statementneeds no modification. B) Synapses can also form between an axonand a cell soma. C) Neuromuscularsynapses form between the axon of a neuron and a muscle. D) Synapses oftenform among the parts of a single cell. E) Synapses can beelectrical as well as chemical.
4) Choose the two primary factors that contribute to the resting membrane potential of a neuron. A) K+leak channels make the cell membrane more permeable to K+. B) Thesodium-potassium pump exports 3 K+ from the cell for every 2Na+ it imports C) Na+leak channels make the cell membrane more permeable to Na+. D) K+leak channels cause a higher concentration of K+ outside thecell. E) The sodium-potassium pump exports 3Na+ from the cell for every 2 K+ it imports
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5) When an action potential begins and sodium channels open, why does sodium rush into the cell? (Check all that apply.) A) The inside of thecell is negatively charged. B) The inside of thecell is positively charged. C) Chloride ions arewaiting to bind to the sodium inside the cell. D) The diffusion gradient drives sodiuminto the cell. E) Channels useenergy to move ions across the membrane whenever they are open.
6) Your roommate takes up smoking, and you hate it. Use what you know about nicotine to convince her to quit. (Check all statements that are true.) A) Nicotine binds toa receptor in the brain that normally receives acetylcholine. B) Nicotine evolvedto protect the tobacco plant by killing grazing cattle. C) The brain adapts to smoking by changingthe levels of this receptor. Over time, more drug is required to get the sameeffect. D) Nicotine is notaddictive, but is still very dangerous. E) Nicotine isidentical to an endogenous ligand in the human body. F) Nicotine evolved to protect the tobaccoplant by killing insects.
7) If sympathetic and parasympathetic neurons both release acetylcholine (ACh), how can they have antagonistic effects? (Check all that apply.) A) The target cellsof each set of neurons respond differently to the same signal. B) Each type ofneuron secretes ACh bound to a different co-neurotransmitter. C) Sympatheticneurons activate the adrenal gland, causing secretion of epinephrine. D) The neuronsrelease different forms of ACh. E) Parasympatheticneurons activate the adrenal gland, causing secretion of epinephrine.
8)
How do somatic neurons and autonomic neurons differ? (Check all that apply.)
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A) Somatic neuronsinnervate the body surface, while autonomic neurons innervate internalstructures. B) Somatic neuronscontrol skeletal muscle, while autonomic neurons control smooth and cardiacmuscle. C) Somatic neuronscontrol exocrine glands, while autonomic neurons do not. D) Somatic neurons control their effectors directly, while autonomic neurons use a series of neurons. E) Somatic neurons are always excitatory,while autonomic neurons may be either excitatory or inhibitory.
9)
Why are mammalian reflexes so fast? (Check all that apply.)
A) They use neuronswith extra-wide axons. B) They complete thesensory input-to-motor output circuit in only 2-3 neurons. C) They do not sendsignals to the brain and back. D) They activate alarge number of sensory neurons, which speeds things up after the motorneuron performs spatial summation. E) There was a selective advantage toevolve rapid responses to certain types of stimuli.
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 10) In vertebrates, the ______ nervous system is composed of the brain and the spinal cord. A) peripheral B) central C) somatic D) autonomic E) sympathetic
11)
What are the branched extensions of a neuron that receive signals called?
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A) axons B) cell bodies C) dendrites D) oligodendrocytes E) synapses
12)
What is the elongated extension of a neuron that nerve impulses travel along? A) axon B) cell body C) dendrite D) oligodendrocyte E) synapse
13)
What are examples of cells that support neurons both structurally and functionally? A) dendrites andnodes of Ranvier B) neuroglia andnodes of Ranvier C) Schwann cells anddendrites D) dendrites, nodesof Ranvier, and neuroglia E) Schwann cells, oligodendrocytes, and other neuroglia
14) You dissect the brain of a mutant mouse and find that parts of the "white matter" look gray. What is a likely cause? A) defects inmyelination B) peripheral nervedamage C) oversizeddendrites D) excessmyelination E) excess neuronalproliferation
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15) Rapid inward diffusion of Na+ produces a dramatic change in membrane potential. What is this event called? A) hyperpolarization B) excitatorypostsynaptic potential C) saltatoryconduction D) monosynapticreflex E) depolarization
16)
Nerve impulses are electrical signals measured across which structure? A) lipid sheath of Schwann cell B) plasma membrane of neuron C) synapse D) neuromuscular junction
17)
The membrane of a resting neuron is most permeable to which of the following ions? A) ClB) Ca2+ C) Na+ D) K+ E) H+
18) When neurons are not producing electrical signals, there is still a voltage difference across their membranes. What is this voltage called? A) channel-gatebias B) electrolytevoltage C) equilibriumpotential D) restingpotential E) ion current
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19) Which of the following characteristics are true for an action potential? I-A threshold potential must be exceeded for an action potential to occur. II-A stimulus either produces a full action potential or none at all. III-During the refractory period it is less likely that stimuli can produce another action potential. A) I only B) I and II C) II and III D) I and III E) I, II, and III
20)
What is the process in which impulses jump from node to node? A) facilitatedtransmission B) refractoryaction C) incompletetransfer D) repolarization E) saltatoryconduction
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21) Which diagram correctly illustrates the distribution of ions in a resting neuron? (Note: A larger symbol indicates a higher concentration of that ion.)
A) A B) B C) C D) D
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22) Which figure correctly illustrates the mechanism of action of the sodium-potassium pump?
A) A B) B C) C D) D
23) What determines the direction of the voltage change that occurs at the postsynaptic membrane? A) the type of neurotransmitter B) the type of secondmessenger system used C) the type(s) of ionsthat travel through opened channels D) the number of ionchannels on the postsynaptic membrane
24) At myelinated areas of the axon (i.e. between nodes of Ranvier), which of the following statements is true? Version 1
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A) There isan increased number of voltage-gated sodium channels. B) There is increasedresistance across the membrane. C) There is increasedcapacitance across the membrane. D) There is increasedtransport of potassium across the membrane.
25)
Which ion channel is primarily responsible for the action potential? A) the voltage-gated sodium channel B) the voltage-gated potassium channel C) the ligand-gated sodium channel D) the ligand-gated potassium channel E) the nongated sodium channel
26) What diffuses across the narrow synaptic cleft between the presynaptic axon and the postsynaptic cell to transmit a nerve impulse? A) neurotransmitter B) electrical impulse C) Na+ ion D) vesicle E) action potential
27)
Which neurotransmitter is released from a motor neuron at the neuromuscular junction? A) acetylcholine B) GABA C) ephinephrine D) dopamine E) serotonin
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28) When acetylcholine stimulates the opening of ligand-gated ion channels on a postsynaptic cell, what is this event called? A) neuromuscularjunction B) temporalsummation C) inhibitorypostsynaptic potential (IPSP) D) excitatorypostsynaptic potential (EPSP) E) synapticintegration
29)
What is the name for the gap into which neurotransmitters are released? A) gap junction B) synapticcleft C) postsynapticmembrane D) presynapticmembrane E) impulsechannel
30) Place the following events that occur at the vertebrate neuromuscular junction in the correct order. I-Depolarization of the muscle fiber membrane. II-Generation of an action potential in the neuron. III-Stimulation of Ca2+ entry into the neuron. IV-Release of acetylcholine into the synapse. A) I, II, III, IV B) III, II, IV, I C) I, III, IV, II D) IV, II,III, I E) II, III, IV, I
31)
Which of the following are examples of biogenic amines?
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A) epinephrine andendorphins B) GABA andserotonin C) epinephrine,dopamine, and GABA D) epinephrine,dopamine, and serotonin E) epinephrine,norepinephrine, dopamine, and serotonin
32) Place the following events involved in drug addiction in the correct sequence. I-The synapse becomes less sensitive, and normal function can only continue in the presence of the drug. II-CNS responds to increased firing by decreasing the number of drug receptors on the cell membrane. III-Drug molecule prevents receptor endocytosis and causes overstimulation of the postsynaptic cell. A) I, II, III B) III, II, I C) II, III, I D) III, I, II
33)
Which of the following drugs has been discovered to bind to acetylcholine receptors? A) serotonin reuptake inhibitors B) thorazine C) cocaine D) codeine E) nicotine
34) The hippocampus, amygdala, and hypothalamus are the major components of the ______ system.
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A) sympathetic B) reflex C) parasympathetic D) limbic E) autonomic
35) The spinal cord is enclosed by the vertebral column and layers of protective membranes. What are these membranes called? A) neural net B) white matter C) dorsal root D) meninges E) viscera
36) Damage to the substantia nigra, a specific region of the basal ganglia, can produce the resting muscle tremors characteristic of what disease? A) epilepsy B) Parkinsondisease C) seizures D) Alzheimerdisease E) insomnia
37) A region of the brain receives both sensory information from ascending nerve tracts and motor commands from the cortex and cerebellum. This region plays an important role in motor control. Which region is it?
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A) basal ganglia B) pituitarygland C) parietal lobe D) thalamus E) medullaoblongata
38) Which area of the cerebral cortex is important for the formulation of thoughts into speech? A) Broca's area B) the pons C) the medullaoblongata D) Wernicke'sarea E) thecerebellum
39) Which animal phylum lacks a network of nerve cells for gathering information from the environment? A) Porifera -sponges B) Cnidaria -jellyfish, sea anenomes C) Platyhelminthes --flatworms D) Nematoda -roundworms E) Mollusca -octopus, squid, clams, snails, and other mollusks
40) In early vertebrates, which component of the brain was devoted largely to coordinating motor reflexes? A) thalamus B) forebrain C) midbrain D) hindbrain E) medullaoblongata
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41) Where did information processing become increasingly centered in terrestrial vertebrates? A) thalamus B) forebrain C) midbrain D) hindbrain E) medullaoblongata
42)
Which region of the CNS listed below is NOT correctly paired with its function? A) Broca's andWernicke's areas—language and speech B) Hypothalamus—regulates body temperature, appetite, and sleep C) Cerebellum—relaystation for ascending and descending tracts D) Corpus callosum—connects the two brain hemispheres E) Hippocampus—memory
43)
Which major regions compose the contemporary vertebrate brain? A) rhombencephalonand prosencephalon only B) mesencephalon andrhombencephalon only C) prosencephalon andmetencephalon only D) metencephalon,rhombencephalon, and prosencephalon E) rhombencephalon,mesencephalon, and prosencephalon
44)
Which of the following structures is NOT a component of the hindbrain? A) pons B) medullaoblongata C) ascendingtracts D) cerebellum
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45)
What is the primary function of the hindbrain in vertebrates? A) temperaturecontrol B) integration ofsensory data C) memorystorage D) control of theheartbeat E) coordination ofmotor reflexes
46)
Where do correlation, association, and learning occur in the brain? A) cerebellum B) corpuscallosum C) medulla D) cerebrum E) pons
47)
What is the site of primary sensory integration in the brain? A) medullaoblongata B) cerebrum C) cerebellum D) thalamus E) corpuscallosum
48)
What region of the brain integrates visceral activities, body temperature, and heartbeat? A) medullaoblongata B) cerebrum C) hypothalamus D) thalamus E) corpuscallosum
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49)
Which of the following is NOT a feature of the limbic system? A) containshippocampus and amygdala B) resides deepwithin the cerebrum C) responsible foremotional responses D) important in theformation and recall of memories E) part of thehypothalamus
50) The doctor informs you that your grandmother's stroke has caused damage to Wernicke's area. Which activity is likely to become more difficult for her? A) walking B) doing laundry C) having aconversation D) sleeping E) mathematicalcalculations
51) What additional factor is required to mediate the parasympathetic effects of acetylcholine? A) G-protein coupledreceptor B) GABA C) AMPAR D) habituation E) synapticintegration
52) Which division of the nervous system regulates the activity of smooth muscle, cardiac muscle, and glands?
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A) antagonisticnervous system B) autonomic nervoussystem C) sympatheticnervous system D) parasympatheticnervous system E) limbic nervoussystem
53)
Which of the following is not part of the peripheral nervous system? A) sympathetic division of the autonomic nervous system B) spinal cord C) parasympathetic division of the autonomic nervous system D) somatic nervous system E) sensory pathways
54)
Which of the following targets is NOT regulated by the autonomic nervous system? A) skeletalmuscles B) cardiacmuscles C) glands of thebody D) smoothmuscles E) none of these
55) Dr. Robinson tapped on a patient's knee with the little hammer, but failed to see the usual kick of the patellar reflex. Since this reflex only involves a few neurons, what part of the nervous system might the doctor most likely be concerned about? A) parasympatheticnervous system B) central nervoussystem C) sympatheticnervous system D) peripheral nervoussystem
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56) Your roommate is on an ultra-low fat diet to try to lose weight. Given what you know about structure of the nervous system, what advice would you give him? A) "You shoulddrink large quantities of water, because the brain is mostly water." B) "Good foryou! Losing weight by any means necessary can only help your brain." C) "You shouldeat some healthy unsaturated fats, like those found in fish, olive oil, andnuts, because your brain needs fatty acids to build the myelin sheaths aroundyour axons." D) "You shouldeat trans fats, from donuts, because 'trans' is short forneurotransmission."
57) What branched structure allows a neuron to take in information from more than one source? A) node ofRanvier B) axon C) myelin D) dendrite
58) What part of the neuron is responsible for most of the "house-keeping" tasks of the cell, including protein synthesis? A) myelin B) axon C) dendrite D) soma E) synapse
59) To process information, postsynaptic neurons often add up simultaneous signals from several presynaptic neurons. Which structure and process allow them to do so? A) axons; temporalsummation B) axons; spatialsummation C) dendrites;temporal summation D) dendrites;spatial summation
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60) A neuron that engages in spatial summation acquires a mutation that causes dendrite overgrowth and promiscuous synapsing. What is the likely outcome? A) abnormally lowfrequency of action potentials B) summation willnot occur C) abnormally highfrequency of action potentials D) action potentialswith stronger depolarization
61)
What important resource do Schwann cells and oligodendrocytes provide to neurons? A) oxygen B) nutrients C) physical strengthfrom microtubules D) Ca2+currents E) insulating layersof membrane
62) A patient suffers from a disease that slows fatty acid synthesis. What is a likely impact of this disease on nervous system function? A) improvedfunctioning due to a healthier weight B) insufficientmyelination and slow axon conduction rate C) improvedfunctioning due to better blood flow D) weaker actionpotentials with smaller depolarization
63) Na+?
Is the resting membrane potential of a neuron closer to the equilibrium potential for K+ or
A) K+ B) Na+ C) It is an averageof the two.
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64) Three-quarters of the substantial amount of energy consumed by the brain is used to run a single molecular machine that maintains the resting potential of neurons. What is this machine called? A) K+leak channel B) sodium-potassiumpump C) acetylcholinereceptor D) voltage-gatedsodium channel E) voltage-gatedcalcium channel
65) Since there is a larger concentration of potassium ions inside a neuron, why is the inside of the neuron negative (-70mV) relative to the outside? A) Potassium ionscarry a negative charge. B) Negatively-charged proteins inside the cell counteract the charge of thepotassium ions. C) The negative signis just a historical convention. D) The highconcentration of sodium ions outside the cell makes the inside negative bycomparison.
66) Sodium ions are single atoms. Why can't they simply diffuse through the cell membrane's lipid bilayer? A) Since they arecharged, ions can't cross the hydrophobic center of the membrane without achannel or pump. B) Sodium ions arecovalently attached in groups of three, which are too large to diffuseeasily. C) Ions do traversethe membrane easily, but the sodium-potassium pump moves them back across. D) Chelator proteinscapture any ions that start to cross the bilayer.
67) If K+ can exit the cell through leak channels, why don't they flow out until there are equal concentrations on both sides of the membrane?
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A) K+ canact as an enzymatic cofactor, and most K+ ions are bound to cellularenzymes. B) The leak channelsallow a very slow leak that cannot keep pace with active import + ofK ions. C) Chelatormolecules trap K+ on the inside of the membrane. D) The negativeelectrical potential inside the cell creates a force that holds theK+ ions in.
68) The outside of a neuron is positively charged at resting potential. Why do K+ ions leave the cell when K+ channels open during an action potential? A) The diffusiongradient is the only factor that affects ion movement. B) K+ions are actively pumped out by the sodium-potassium pump acting inreverse. C) Voltage-gated K+channels open when membrane potential reaches +50 mV during the depolarizationphase. The diffusion gradient and electrical force cooperate to drive K+ ionsout of the cell. D) Negativelycharged proteins leave the cell at the onset of the action potential.
69) The outside of a neuron is positively charged at resting potential. Why don't negative ions exit from the cell to normalize charge across the membrane? A) The positivecharge outside the cell repels negative ions. B) There are nonegative ions inside the cell. C) All of thechloride ions are already outside the cell. D) The negativecharge inside the cell is carried by large proteins that cannot diffuse throughthe membrane.
70)
What does the Nernst equation allow us to do? A) Predict thefunction of a specific type of neuron. B) Calculate theequilibrium potential for an ion. C) Use a computerprogram to model axonal transmission. D) Calculate themagnitude of depolarization during an action potential.
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71)
What limits the frequency of action potentials? A) chloride ions B) spike amplitude C) nodes ofRanvier D) refractoryperiod
72) A patient of yours is injured in a car accident. The surgeon reports that while there is damage to the dorsal roots, the spinal cord and nerves otherwise appear intact. What functions would you expect to be affected in the patient? A) The patient maylose somatic function, but should retain autonomic function. B) The patient maylose motor function, but should retain sensory perception. C) The patient maylose some sensory perception, but should retain motor function. However, lackof proprioceptive input may make muscle control difficult. D) The patient maylose parasympathetic function, but should retain sympathetic function. Theyshould avoid stressful situations.
73)
How do temporal and spatial summation improve the processing power of the brain?
A) Temporal summationallows circadian rhythms to regulate neuronal activity. Spatial summationallows latitude to regulate neuronal activity. B) Temporal summationallows a neuron to fire prolonged action potentials, and spatial summationallows a neuron to synapse onto new targets. C) Temporal andspatial summation both make the neuron more likely to fire actionpotentials. D) Temporal summationallows a neuron to recognize a persistent signal from a single presynapticcell, and spatial summation allows a neuron to recognize a broad signal frommultiple presynaptic cells.
74) K+ channels in the heart do not have binding sites for ACh, yet parasympathetic release of ACh causes outward flux of K+ from heart cells. How does this occur?
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A) ACh triggersrelease of epinephrine from the adrenal glands, which in turn causes K+ fluxout of heart cells. B) ACh binds to aG-protein coupled receptor on heart cells, and the G protein alpha subunitbinds to a separate K+ channel and causes it to open. C) Parasympatheticneurons activate sympathetic neurons, which directly cause K+ fluxfrom heart cells. D) ACh binds andactivates a K+ pump on heart cells.
75) What would happen if the G-protein coupled receptor in heart cells that binds to ACh had a mutation that caused it to bind more tightly to the G-protein alpha subunit? A) G-proteinactivation and K+ channel opening would happen more quickly. Heart rate mayremain abnormally low, impairing response to stress. B) This would leadto K+ flow out of heart cells, causing increased hyperpolarization. C) G-proteinactivation and K+ channel opening would be slowed. Heart rate may remainabnormally high, especially following stress. D) This would leadto K+ flow into heart cells, causing increased depolarization.
SECTION BREAK. Answer all the part questions. 76) Nodes of Ranvier are the spaces between sections of axon enwrapped with myelin. Because myelin creates an insulating layer that prevents ion flow, the progress of the action potential "jumps" from node to node, thus speeding up transmission down the axon.
76.1) You are studying a gene which, when mutant, causes oligodendrocytes to enwrap shorter sections of axon, so that nodes of Ranvier are more closely spaced. What is the likely effect on nerve impulses?
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A) They will travelfaster. B) They will travel slower. C) They will increasein amplitude. D) They will decreasein amplitude. E) They will travellaterally across connected axons.
76.2)
What other cells should you examine for effects from this mutant gene?
A) prefrontalneurons B) gustatoryneurons C) cholinergicneurons D) Schwann cells
77) The PNS comprises the somatic (voluntary) and autonomic (involuntary) nervous systems. The sympathetic division of the autonomic nervous system activates the body for fight-or-flight responses. The parasympathetic division generally promotes relaxation and digestion (or "rest and digest").
77.1) A cheetah is chasing a gazelle. What division of the vertebrate nervous system is regulating the stress response in both animals? A) somatic nervoussystem B) parasympatheticnervous system C) sympathetic nervoussystem D) parasymbioticnervous system E) cerebral cortex
77.2) A cheetah has succeeded in catching a gazelle and has just finished feeding on the carcass. What division of the nervous system has increased in activity?
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A) somatic nervoussystem B) parasympatheticnervous system C) sympathetic nervoussystem D) parasymbioticnervous system E) cerebral cortex
78) Charcot-Marie-Tooth is the most commonly inherited peripheral neuropathy, and has no known cure. Patients suffer damage to motor and sensory neurons, leading to degeneration of muscles and gradual loss of motor control.
78.1) What do the two sets of neurons damaged in Charcot-Marie-Tooth neuropathy comprise? A) peripheral nervoussystem B) autonomic nervoussystem C) somatic nervoussystem D) parasympatheticnervous system E) central nervoussystem
78.2) Genetic studies have found that Charcot-Marie-Tooth may be caused by a mutation in the gene Mitofusin-2 (MFN2), which causes mitochondria to form large clumps. In what area of a neuron are these clumps most likely to cause a problem? A) axon B) synapse C) soma D) dendrite E) myelin
78.3) Mutation of the peripheral myelin protein 22 ( PMP22) gene, which causes demyelination of peripheral neurons, is a more common cause of Charcot-Marie-Tooth disease. In which cells is the PMP22 gene important for normal function? Version 1
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A) Schwann cells B) preganglionic neurons C) postganglionic neurons D) oligodendrocytes E) interneurons
78.4) How can mutations in different genes, functioning in different cells, lead to the same disease? From the following, choose the best responses to complete the sentences: "Physiological function requires that multiple cells work together. Various defects in different cells can impair function, leading to ___________ that are indistinguishable at the level of the whole organism. In Charcot-Marie-Tooth disease, motor nerve function can be impaired either by a problem within _______________ , or a problem in __________________ causing _______________." A) defects; somaticcells; oligodendrocytes; demyelination B) symptoms; motor neurons; Schwann cells; demyelination C) symptoms; sensoryneurons; Schwann cells; fast axonal transport D) genotypes;dendrites; axons; fast axonal transport
78.5) Subsequent to motor neuron degeneration in Charcot-Marie-Tooth disease, muscles begin to weaken and degenerate as well. What is the likely cause? A) Muscles willatrophy if they don't receive regular stimulation from motor neurons. B) Muscles requirehealthy Schwann cells for myelination as well. C) Muscles containlarge numbers of mitochondria. D) Toxins leak outfrom the dying motor neurons onto the muscles.
78.6) Which diagnostic test(s) would you recommend for a patient that you suspect is showing signs of early stage Charcot-Marie-Tooth disease? (Check all that apply.)
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A) Culture and proteinexpression profile of oligodendrocytes B) EKG to look for rhythmicabnormalities C) EMG to test muscleresponses D) fMRI of the frontal lobe of the brain E) fMRI of the rACC of the brain F) Genetic testing formutations in the PMP22 and MFN2 genes G) Nerve biopsy tolook for signs of demyelination H) Nerve conduction studyto test the rate of impulse conduction
79) The word hyponatremia derives from the words hypo ("under" or "less") and natrium ("sodium"). The word natrium is the basis for the abbreviation Na for sodium. Hyponatremia is a rare condition, but has become of more concern with the rise in amateur runners participating in marathons. Since they run slower, they spend longer on the course and have more opportunity to drink water and sweat out additional sodium.
79.1) Marathon runners are encouraged to stop at water stations along the course to stay hydrated. However, occasionally a runner drinks too much water and suffers from hyponatremia, or "water intoxication". While water itself is not toxic, drinking too much can upset ion balance in the extracellular space. Based on what you know about ions and nerve signaling, the levels of which important ion are most likely to be disrupted in hyponatremia? A) hydrogen B) potassium C) calcium D) sodium E) oxygen
79.2) You are an EMT on duty for the marathon. It is an extremely hot day. You say to your partner, "This weather is likely to _____________ the risk of hyponatremia, because ______________ will cause the athletes to lose ______________."
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A) increase,sweating, sodium B) decrease,urination, calcium C) decrease,shivering, potassium D) increase,panting, oxygen
80) A typical AA battery has a potential of 1.5V. One can think of the potential in a neuron as having similarities to that of a battery.
80.1) If you were to compare the resting potential of a neuron to a battery, which way is the battery oriented? A) positive terminaloutside of the cell, and negative terminal inside B) positive terminalinside of the cell, and negative terminal outside C) positive terminalpointing toward the axon, negative terminal toward the dendrite D) positive terminalpointing toward the dendrite, negative terminal toward the axon E) both terminalsinside the cell soma
80.2) How does the resting potential of a typical neuron compare to that of a 1.5V AA alkaline battery? A) A typical neuronhas a resting potential of -70mV, or about 5% the voltage of the battery. B) A typical neuronhas a resting potential of -70V, or about 50x the voltage of the battery. C) A typical neuronhas a resting potential of +70mV, or about 5% the voltage of the battery. D) A typical neuronhas a resting potential of +70V, or about 50x the voltage of the battery.
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81) Palytoxin is incredibly toxic, perhaps the second most dangerous non-peptide toxin. It targets the sodium-potassium pump, locking it open and forming a channel through which the ions can passively flow. Palytoxin is produced by zoanthid cnidarians (soft coral), and there have been incidents of poisoning from zoanthids within marine aquaria tanks in people's homes. It is also thought to be the source of the legend of the Limu make o hana ("Seaweed of Death from Hana").
81.1) A Hawaiian legend tells of a village that angered a shark god. In revenge, a "seaweed" began to grow in the tidepools that killed anyone who touched it. In fact, this "limu-make-o-Hana" -- a zoanthid cnidarian -- contains a palytoxin that locks the sodiumpotassium pump open, allowing free flow of ions. If a villager suffers palytoxin poisoning, which way will the ions in his neurons flow? A) all ions willflow out B) potassium in,sodium out C) chloride andsodium out, potassium in D) sodium in,potassium out
81.2)
What is the likely impact of this toxin on the resting potential of a neuron?
A) The resting potential will require more energy to maintain. B) The restingpotential will be more negative. C) It will destroythe ion gradients necessary for the resting potential. D) The restingpotential will promote action potentials with a larger depolarization.
81.3)
What is the likely impact of this toxin on action potentials?
A) They will occurmore frequently. B) They will bestronger and more unpredictable. C) Without iongradients, action potentials are not possible. D) They will havelonger refractory periods.
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82) Botulinum toxin-- A toxin produced by the bacterium Clostridium botulinum. Known for sometimes lethal poisoning from infected meat products. In modern controlled medical or cosmetic use, the very same toxin is known as Botox. Tetanus toxin-- Another very potent neurotoxin produced by Clostridium tetani. Strichnine-- A highly poisonous alkaloid produced by the Strychnos nux-vomica tree, historically used to kill rats and other pests.
82.1) Botulinum toxin, or "botox", has become popular for cosmetic surgery. The toxin prevents neurosecretory vesicles from docking at the plasma membrane and releasing neurotransmitter. How would this toxin affect the neuromuscular junction? A) Since ACh is notreleased, the muscles stay in a state of repeated contraction. B) Since ACh is notreleased, the muscles are not activated to contract and remain relaxed. C) Buildup of AChcauses promiscuous activation of all nearby sensory neurons. D) Buildup of AChleaks back into the brain, creating a calming effect.
82.2) You accidentally consume botulinum toxin by eating a contaminated can of sausages. What do you predict will be the most harmful physiological effect? A) slowed actionpotential conduction B) respiratoryfailure due to spastic paralysis (constant muscle contraction) C) respiratoryfailure due to flaccid paralysis (relaxed muscles) D) pupil dilation
82.3) Another toxin that also blocks neurotransmitter release is tetanus toxin; however, it primarily affects inhibitory interneurons of the spinal cord that negatively regulate motor neurons. Which would be symptoms of tetanus toxin poisoning? A) flaccidparalysis B) spasticparalysis C) slowed action potential conduction D) pupil dilation
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82.4) In contrast to these toxins, strychnine acts postsynaptically, to block glycine from binding to receptors on motor neurons. Would you expect the symptoms of strychnine poisoning to be more similar to those of botulinum or tetanus toxin? A) botulinum B) tetanus toxin C) botulinum
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Answer Key Test name: Chap 42_13e_Raven 1) FALSE 2) FALSE 3) [B, C, E]
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Clarify Question • What is the key concept addressed by the question? o Types of synaptic connections. • What type of thinking is required? o This is an analyze question because you have to break synapses into their component pieces to understand the cell types and parts of cells that are involved. Gather Content/Choose Answer • What do you already know about synapses? What other information is related to the question? o To solve this problem, you’ll need to understand what a synapse is and where they can be found. Synapses are connections between the axon of one neuron and the dendrite of another neuron. By definition, synapses are connections between two cells, so answer (d) cannot be correct. The question states that this is where neurotransmitters transmit a chemical signal, but are neurotransmitters the only way to send a signal from one neuron to another? No, electrical synapses allow ion flow across gap junctions from one neuron to another without the use of neurotransmitters. Can synapses occur between an axon and a muscle cell (neuromuscular junction) or the soma of another neuron? Yes, they can. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, good job! If not, where did you go wrong? Answering this question correctly depended not only on Version 1
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distinguishing between chemical synapses and electrical synapses, but on your ability to break down different categories of synaptic connections. If you got an incorrect answer, did you remember that a neuromuscular junction is a synapse, or remember that neurons can also have electrical synapses? While synapses commonly occur between axons and dendrites, did you recall that they can also occur at the soma? 4) [A, E] 5) [A, D] 6) [A, C, F]
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Clarify Question • What is the key concept addressed by the question? o The effect of nicotine on the nervous system. • What type of thinking is required? o This is an analyze question because you have to consider various aspects of nicotine and its effect on the brain. Gather Content/Choose Answer • What do you already know about nicotine? What other information is related to the question? o To solve this problem, you’ll need to understand that nicotine binds to acetylcholine receptors in the vertebrate brain. It affects the central nervous system of insects, which is why tobacco plants evolved the ability to produce this compound. The vertebrate brain changes in response to long-term nicotine exposure by decreasing the number of acetylcholine receptors and by altering their sensitivity. As a result, more nicotine is required to result in the same effect as before. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, good job! If not, where did you go wrong? Did you think that nicotine evolved to protect the tobacco plant by killing grazing cattle? While tobacco has a similar effect on all mammals (like us), it usually does not kill them. Also, nicotine evolved long before humans domesticated cattle, so answer (B) is not correct. Nicotine is not identical to an endogenous ligand in the human body (answer E), but its shape fits into endogenous acetylcholine receptors, Version 1
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and can be very addictive (answer D). 7) [A, C]
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Clarify Question • What is the key concept addressed by the question? o How can systems that have opposite effects be controlled by the same neurotransmitter? • What type of thinking is required? o This is an analyze question because you have to determine the mechanism of opposite outcomes resulting from the release of the same neurotransmitter (ACh). Gather Content/Choose Answer • What do you already know about the sympathetic and parasympathetic systems? What other information is related to the question? o To solve this problem, you’ll need to know that the sympathetic and parasympathetic systems have opposite physiological effects. For example, activation of the sympathetic system increases heart rate while the parasympathetic system slows it down. While both systems release ACh, the sympathetic system activates the adrenal gland to secrete epinephrine. ACh release in the parasympathetic division slows the heart, increases secretions and activities of the digestive system, while the ACh-mediated release of epinephrine has the opposite physiological effects. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, great! If not, where did you go wrong? Did you remember that neurons often release more than one Version 1
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neurotransmitter? That is correct, but these co-transmitters are not bound together (answer B). Did you think that there are different forms of ACh (answer D)? It is true that there are different types of ACh receptors, but only one form of ACh. Were you confused about which division of the autonomic nervous system activates the adrenal gland? It is the sympathetic neurons that activate it, not parasympathetic neurons. 8) [B, D, E] 9) [B, C, E]
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Clarify Question • What is the key concept addressed by the question? o Cause of the speed of reflexes. • What type of thinking is required? o Answering this question correctly depended not only on distinguishing between the different components of a reflex arc, but also analyzing why this neural set-up promotes speed of signal transmission. Gather Content/Choose Answer • What do you already know about reflexes? What other information is related to the question? o To solve this problem, you’ll need to know that a reflex arc is composed of only 2 or 3 neurons that connect in the spinal cord. One is a sensory neuron that has its cell body in the dorsal root ganglia outside of the spinal cord. Sometimes these neurons synapse directly to a motor neuron which exits the spinal cord through the ventral roots. Often, the connections between these two types of neurons are modulated by interneurons, which are commonly inhibitory. All of these connections occur in the spinal cord and not the brain, which makes the distances that these signals travel much shorter and faster. These faster responses have evolved to help vertebrates respond rapidly to stimuli that could be dangerous. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, great! If not, where did you go wrong? Did you think that neurons in reflexes are so fast because they Version 1
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are so large in diameter? It is true that action potentials are conducted faster down larger axons than smaller ones, but many of the axons involved in reflexes are not large (for example, simple pain receptors). Did you think that large numbers of sensory neurons would speed a reflex up? Probably not. If anything, it might slow things down. Spatial summation involves input from multiple neurons, but a reflex could only involve two neurones, so the answer beginning with 'They activate a large number of sensory neurons' cannot be correct. 10) B 11) C 12) A 13) E 14) A
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Clarify Question • What is the key concept addressed by the question? o The question is asking about what structure makes “white matter” white in color and what would happen if this structure was disrupted due to mutation? • What type of thinking is required? o This question is asking you to apply what you know about white matter to solve what mutation the mouse has. • What key words does the question contain? o White matter, gray, mutant. Gather Content/Choose Answer • What do you already know about white matter? How does it relate to the question? o To solve this problem, you’ll need to apply your knowledge of the differences between white matter and gray matter. Recall that myelinated axons form white matter while unmyelinated dendrites and cell bodies form gray matter. Thus, the answer likely related to myelination. Consider Alternatives • What other information is related to the question? o Although not directly discussed in this chapter, in earlier chapters the concept of mutation was introduced. Remember that a mutation is the change of a gene, often resulting in the change of the structure of a protein. Structural changes in proteins often lead to the protein becoming non-functional. As myelination produces a white color, loss of this color (to gray) is likely due to the loss of a protein involved in myelination.
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o At this point, you should have everything you need to know to answer the question. Since white matter has myelinated axons and gray matter has unmyelinated dendrites and cell bodies, you can deduct that the mutation that has caused the white matter to look gray has to do with myelination (answers A and D). If myelinated axons appear white, then excess myelination would make the brain appear white, but a defect in myelination would make the brain appear gray. Therefore answer A must be the correct answer. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, excellent! Remember, if you practice how to analyze and solve problems they will lead you to the correct answer more often than not. If you arrived at an incorrect answer, did you remember that white matter is found in parts of the brain where axons are myelinated? Did you remember that mutation is gene change that can lead to defects in proteins? o Was it clear to you that the type of thinking needed to answer this question is to apply your knowledge to a new concept (in this case applying knowledge of myelination to a new mouse mutation)? Consider where in the problem solving process your thinking went astray. 15) E 16) B 17) D Version 1
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18) D 19) E 20) E 21) B Clarify Question • What is the key concept addressed by the question? o The question is asking about the relative distribution of key ions (sodium, potassium, and chloride) across the membrane of a neuron. • What type of thinking is required? o This question is an analyze question because you have to understand the differential distribution (shown by the size of the icons) of ions in a neuron during its resting state. Gather Content/Choose Answer • What do you already know about ions in cells? What other information is related to the question? o To solve this problem, you’ll need to apply your knowledge of the differential concentration of ions across all cell membranes, which causes a membrane potential. At rest this potential is referred to as the resting membrane potential, as opposed to an action potential, which is caused by a rapid, but transient, shift away from the resting membrane potential. Resting membrane potential is largely controlled by the distribution of K+ ions, with equilibrium being reached with much greater K+ inside the cell compared to outside the cell. Action potentials are produced by an influx of Na+ ions going down their concentration gradient. Thus, the concentration of Na+ must be greater outside the cell than inside. Remember that this unequal distribution of Na+ and K+ is produced by sodium-potassium pumps that transport 2 potassium ions inside and 3 sodium ions outside of the cell. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, great! If not, where in your thought process did things go wrong? If you arrived at an incorrect answer, were you thinking that a neuron at rest should have its ions in equilibrium and did you wrongly assume that electrochemical equilibrium meant that concentrations of ions are the same on both sides of the membrane? o Answering this question correctly depended upon on distinguishing between the differing distribution patterns of Na+, K+, and Cl- ions while at resting membrane potential. Version 1
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22) C 23) C 24) B 25) A 26) A 27) A 28) D 29) B 30) E 31) E 32) B 33) E 34) D 35) D 36) B 37) A 38) D 39) A 40) D 41) B 42) C 43) E 44) C 45) E 46) D 47) D 48) C 49) E 50) C
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Clarify Question • What is the key concept addressed by the question? o The question is asking about the functional affect of damage (caused by a stroke) to Wernicke’s area. • What type of thinking is required? o This question is an evaluate question because it is asking you to determine what the logical symptoms this patient (your grandmother) would most likely experience if Wernicke’s area was damaged. Gather Content/Choose Answer • What do you already know about Wernicke’s area? What other information is related to the question? o To solve this problem, you’ll need to apply your knowledge of the function of Wernicke’s area. There are two main brain areas associated with speech- Wernicke’s and Broca’s areas. Wernicke’s area is involved with understanding speech while Broca’s area is involved in producing speech. Thus, a stroke that damaged Wernicke’s area would result in a patient having difficulty understanding speech during a conversation. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, great! If not, where in your thought process did things go wrong? Answering this question correctly depended on your ability to weigh and judge, or evaluate, the effects of damage to Wernicke’s area. If you got an incorrect answer, did you remember that Wernicke’s area is involved in understanding speech? Did you think that Wernicke’s area was involved in a different function, Version 1
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such as sleep or locomotion? 51) A 52) B 53) B 54) A 55) D
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Clarify Question • What is the key concept addressed by the question? o The question is asking you to think about the components of a kneejerk reflex and understand which part of the nervous system is involved. • What type of thinking is required? o This question is asking you to identify key components of a reflex arc and then evaluate which components belong to which part of the nervous system to predict which system the doctor would be concerned about potential damage to. Gather Content/Choose Answer • What do you already know about components of the nervous system? What other information is related to the question? o To solve this problem, you’ll need to apply your knowledge of the function and categorization of the nervous system and a reflex arc.The patellar hammer stretches the leg muscle and activates stretch receptors in the muscle which sends a neural signal through sensory neurons which travel to the dorsal root ganglion and into the spinal cord. Within the spinal cord, the sensory neurons synapse directly to motor neurons which travel back down to the leg muscle and cause it to contract, raising the leg. The sensory and motor neurons involved are part of the peripheral nervous system, although they synapse in the spinal cord, which is a part of the central nervous system. If the patellar reflex is non-functional, then it is likely the result of damage to peripheral nerves (either sensory or motor). Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? o If you figured out the correct answer, great! If not, where in your thought process did things go wrong? Did you remember that the sympathetic and parasympathetic systems are divisions of the autonomic nervous system which is controlled by the medulla oblongata in the brain (which is part of the central nervous system)? You may have thought that since the sensory and motor neurons synapse in the spinal cord, which is part of the central nervous system, that lack of a reflex response could be the result of damage to the spinal cord. This is a possibility, but if there was a serious spinal injury which may have paralyzed the patient’s legs, it is unlikely that the doctor would rely on a simple knee-jerk reflex to test the paralysis. Thus, you can assume the doctor is concerned about the main components of the reflex arc, the sensory and motor neurons, which are part of the peripheral nervous system. 56) C
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Clarify Question • What is the key concept addressed by the question? o The question is asking you to give diet advice to your friend trying to lose weight. • What type of thinking is required? o This question is asking you to evaluate the potential negative consequences of an ultra-low fat diet on the nervous system. Gather Content/Choose Answer • What do you already know about components of the nervous system? What other information is related to the question? o To solve this problem, you’ll need to apply your knowledge of the importance of lipids in the nervous system. Myelin is the lipid-rich layer wrapped around axons to insulate them. This insulation speeds up conduction of action potentials. Thus, lipids are vital for the nervous system to operate properly. Axon tracts in the brain and spinal cord are called white matter because this lipid-rich material has a shiny, white appearance and makes up a considerable portion of the nervous system. Thus, a diet with some lipids is necessary for a healthy nervous system. Drinking sufficient water is also important to one’s health, but the question addresses fat and not water. Trans fats is not short for neurotransmission so you can eliminate that answer. Losing weight by any extreme means can actually be very dangerous for your health, but eating moderate levels of healthy, unsaturated fats can provide the lipids needed to myelinate your axons. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? o If you figured out the correct answer, good job! If not, where did you go wrong? Did you think that the answer was (a) because our brain, as well as most of our cells, are primarily water? This is true but the diet your roommate is on is an ultra-low fat diet, and water was not mentioned. Did you get fooled into thinking that trans fats really is short for neurotransmitter fats? 57) D 58) D 59) D 60) C
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Clarify Question • What is the key concept addressed by the question? o The effects of dendrite overgrowth on spatial summation. • What type of thinking is required? o The question is asking you to evaluate the effects of dendrite overgrowth on spatial summation and action potential production. Gather Content/Choose Answer • What do you already know about summation? What other information is related to the question? o To solve this problem, you’ll need to understand spatial summation. Often, the excitatory post-synaptic potential (EPSP) coming from one dendrite is not great enough to reach threshold, and thus elicit an action potential in the post-synaptic neuron. But as the post-synaptic neuron usually has many dendrites synapsing with it, the potential of the neuron is determined by the summation of all the excitatory (EPSP) and inhibitory (IPSP) inputs from these multiple synapses. If a neuron produces more dendrites, it will increase the chance of more EPSPs from separate dendrites, thus improving the probability that an action potential will “fire” and increasing the rate of firing. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, good job! If not, where did you go wrong? Did you think that more dendrites and more summation would lead to action potentials with greater amplitudes? Remember that action potentials are “all-or-none” responses that increase in frequency, Version 1
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not amplitude, in response to excitatory stimuli. Answer (b) stated that summation would not occur, but increasing the number of synapses increases the probability of summation instead of decreasing it. 61) E 62) B
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Clarify Question • What is the key concept addressed by the question? o Importance of fatty acids on the nervous system. • What type of thinking is required? o This is an analyze question because you have to extend your knowledge of the importance of fatty acids to a potential nervous system disease. Gather Content/Choose Answer • What do you already know about fatty acids? What other information is related to the question? o To solve this problem, you’ll need to understand why fatty acids are important to the nervous system. Recall that myelin, which is wrapped around axons to improve action potential conduction, is lipid rich. Thus, a disease that slows fatty acid synthesis may also slow myelination, which would presumably slow axon conduction rate. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, good job! If not, where did you go wrong? Answering this question correctly depended on extending your knowledge of the role of fatty acid synthesis in the nervous system. If you got an incorrect answer, did you remember that action potentials do not get weaker or stronger, but either decrease or increase in frequency? This would have eliminated answer (D). Lipids, in excess and depending upon what type, can promote plaques in blood vessels which can block their flow, not improve their flow, so answer (C) is not Version 1
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correct. That leaves answers A and B. While losing weight can benefit one’s health and even the functioning of the brain, there is no definitive information given stating that the patient actually lost weight, which leaves answer (B). 63) A 64) B 65) B 66) A 67) D 68) C 69) D 70) B 71) D 72) C
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Clarify Question • What is the key concept addressed by the question? o The role of dorsal root ganglia. • What type of thinking is required? o This is an evaluate question because you have to determine the clinical effects of damage to the dorsal root ganglia of a patient. Gather Content/Choose Answer • What do you already know about dorsal root ganglia? What other information is related to the question? o To solve this problem, you’ll need to know what dorsal root ganglia are. Dorsal root ganglia are where the cell bodies of sensory neurons are grouped together outside each level of the spinal cord. Sensory neurons enter the dorsal root and motor neurons leave the ventral root of the spinal nerve. Since your patient has damaged his dorsal roots, then you would predict that he will lose some input coming from sensory neurons and thus some sensory perception. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, good job! If not, where did you go wrong? Did you confuse dorsal roots (which are sensory) with ventral roots (which are motor)? Did you forget that both the sympathetic and parasympathetic parts of the autonomic system sends sensory neurons to the dorsal root ganglia (excluding answer D), which is the same pathway used in somatic function (eliminating answer A)?
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73) D
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Clarify Question • What is the key concept addressed by the question? o Similarities and differences between spatial and temporal summation. • What type of thinking is required? o Answering this question correctly depended not only on distinguishing between temporal and spatial summation, but on your ability to break down, or analyze, the advantages or benefits of each. Gather Content/Choose Answer • What do you already know about summation? What other information is related to the question? o To solve this problem, you’ll need to remember that that in spatial summation, graded potentials due to dendrites from different presynaptic neurons that occur at the same time add together to potentially reach an above-threshold voltage and thus initiate an action potential. In temporal summation, a single dendrite can produce sufficient depolarization to produce an action potential if it produces EPSPs that are close enough in time to sum to an above-threshold voltage. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, great! If not, where did you go wrong? Did you think that temporal summation and circadian rhythms were linked because they both have to do with time? It is true that both concepts relate to time, but the question is asking about the processing power of the brain. Temporal summation does not allow for prolonged action potentials (answer B), as they are an all-or-none response, but Version 1
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both temporal and spatial summation can regulate whether an action potential will be elicited by producing above-threshold voltages. Summation does not necessarily make a neuron more likely to fire (answer C), because it depends upon whether the signals that are summed are excitatory or inhibitory. 74) B 75) C
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Clarify Question • What is the key concept addressed by the question? o Heart problems caused by a mutation in a G-protein coupled receptor. • What type of thinking is required? o Answering this question correctly depended not only on distinguishing between the different components of a G-protein coupled receptor signaling pathway, but also analyzing what types of defects would occur if parts of the pathway were interrupted. Gather Content/Choose Answer • What do you already know about G-proteins? What other information is related to the question? o To solve this problem, you’ll need to know that G-protein coupled receptors do not have an ion channel themselves. Instead, following the binding of a ligand to its receptor, a G-protein is activated which then opens up separate ion channels. In heart cells, when ACh binds to it receptor, G-proteins are activated which then open up potassium channels. Recall that the concentration of potassium is greater inside the cell, so that when ion channels are opened, potassium ions will flow out of the cell down their concentration gradient. As this happens, the cell will be hyperpolarized, slowing the heart rate. If the G-protein was bound more tightly to the receptor, it would be less able to activate the potassium channels. This would depolarize the cell, leading to contraction and increased heart rate. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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o If you figured out the correct answer, great! If not, where did you go wrong? Did you think that the potassium channel was binding to the Gprotein more tightly (which would leave the channel open, hyperpolarizing the cell and slowing heart rate)? If so, it was easy to misread this question, but it states that the G-protein coupled receptor had the mutation and not the channel. Binding to the receptor would make it harder to get to the ion channel such that the channel would be closed much of the time, which would depolarize the cell and increase heart rate. Did you get confused about the concentration gradient of potassium across the membrane? Potassium is more concentrated inside the cell compared to extracellular fluid, and thus will flow out of the cell when ion channels are opened. 76) Section Break 76.1) B
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Clarify Question • What is the key concept addressed by the question? o The question is asking about the function of nodes of Ranvier in action potential conduction. • What type of thinking is required? o This question is asking you to take your knowledge concerning nodes of Ranvier and to analyze the effects of changes to these nodes. • What key words does the question contain? o Nodes of Ranvier, spaced, nerve impulses, oligodendrocytes. How are all these terms related? Gather Content/Choose Answer • What do you already know about nodes of Ranvier? How do they relate to nerve impulses? o To solve this problem, you’ll need to apply your knowledge of the form and function of nodes of Ranvier, which are unmyelinated regions of axons. Remember that myelin insulates axons by preventing ions from leaking out. Since ions only flow into the axon at nodes of Ranvier, this is where action potentials are generated. Following an action potential at one node, sodium rapidly diffuses to the next node, producing an action potential there in a saltatory manner. Consider Alternatives • What other information is related to the question? o The answers are all related to how node of Ranvier spacing could influence nerve impulses (action potentials). You should recall that action potentials are all-or-none responses that do not increase in Version 1
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amplitude with increased stimulation and that action potentials move along axons to dendrites of another neuron, not laterally across adjacent axons. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o At this point, you should have everything you need to know to answer the question. Since you know that action potentials do not increase or decrease in amplitude and you also know that action potentials do not travel from axon to axon, but from axon to dendrite, you can eliminate most of the answer options. So the question is whether tighter spacing would increase or decrease action potential conduction speed. Since myelination speeds up action potentials by preventing ion leaking, and the more nodes of Ranvier that there are, the less overall myelination of the axon, you can deduce that more nodes would decrease the speed of nerve impulses. Therefore B must be the correct answer. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, wonderful! If not, where in your thought process did things go wrong? If you arrived at an incorrect answer, did you remember that nerve impulses are all-ornone events that do not change amplitude? Did you remember that myelination speeds up action potential conduction and that action potentials only occur at nodes of Ranvier? Version 1
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o Was it clear to you that the type of thinking needed to answer this question is to analyze your knowledge about nerve impulses to predict the effects of a shift away from normal conditions? Consider where in the problem solving process your thinking went astray. 76.2) D
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Clarify Question • What is the key concept addressed by the question? o The question is asking about the effects of a specific mutation on types of neural cells. • What type of thinking is required? o This question is asking you to take your knowledge concerning myelination and to evaluate which cell types will most likely be affected. • What key words does the question contain? o Cells, effects, mutant gene, oligodendrocytes (from previous question). How are all these terms related to the previous question? Gather Content/Choose Answer • What do you already know about this mutation? Which cell type do we know it affects? o To solve this problem, you’ll need to apply your knowledge of the form and function of nodes of Ranvier, which are unmyelinated regions of axons. The mutation causes oligodendrocytes to enwrap shorter sections of axons with myelin. Remember that oligodendrocytes enwrap axons with myelin in the central nervous system, and Schwann cells perform the same function in the peripheral nervous system. Consider Alternatives • What other information is related to the question? o The answers are all types of neural cells. The first three are types of neurons, and the last answer, Schwann cells, is a type of neuroglia. We learned in the previous question that oligodendrocytes were affected by the mutation? What type of cell Version 1
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is an oligodendrocyte? It is a glial cell. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o At this point, you should have everything you need to know to answer the question. Since you know that the mutation affects oligodendrocytes and not not neurons, you can eliminate the answers other than Schwann cells. In further support of Schwann cells as the answer, you know that oligodendrocytes and Schwann cells are both glial cells that myelinate axons. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, great! If not, where in your thought process did things go wrong? If you arrived at an incorrect answer, were you thinking that one of the neuron types was the answer because the mutation affects nerve impulses? Did you remember that both oligodendrocytes and Schwann cells perform the same myelination function? o Was it clear to you that the type of thinking needed to answer this question is to evaluate different neural cell types and find one that myelinated axons as oligodendrocytes do? Consider where in the problem solving process your thinking went astray. 77) Section Break 77.1) C Version 1
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77.2) B 78) Section Break 78.1) A 78.2) A
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Clarify Question • What is the key concept addressed by the question? o The question is asking you to evaluate which part of an neuron would be prone to disfunction because of mitochondrial clumping. • What type of thinking is required? o This question is asking you to judge which part of an neuron would be the most vulnerable to blockage of neural transmission. Gather Content/Choose Answer • What do you already know about components of the nervous system? What other information is related to the question? o To solve this problem, you’ll need to apply your knowledge of the morphology and physiology of a neuron. The long thin structure of the axon makes it vulnerable to “traffic jams” from clumps of proteins or organelles. This can block fast axonal transport of neurotransmitters and their precursors to the synaptic terminal. Without neurotransmitters chemical synapses cannot function. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, wonderful! If not, where in your thought process did things go wrong? Did you think that dendrites are thin and could be blocked by clumped proteins? That is a possibility, but dendrites are usually much smaller and shorter than axons. Also, transport of neurotransmitters and their precursors occur along axons, not dendrites, so blocking axons would be more Version 1
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detrimental to the working of the neuron than the blocking of a few of many dendrites. Mitochondria do come from the soma, but the soma is so large that mitochondrial clumping would probably not inhibit action potentials. Myelin is an important part of the axon, but it occurs outside the neuron and so does not have contact with mitochondria (with its potential clumping) from the soma. 78.3) A
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Clarify Question • What is the key concept addressed by the question? o The question is asking you about the causes of demyelination in peripheral neurons. • What type of thinking is required? o This question is asking you to apply your knowledge about the cells in the PNS and how they could affect demyelination of axons. Gather Content/Choose Answer • What do you already know about components of the nervous system? What other information is related to the question? o To solve this problem, you’ll need determine which cells affect myelination of axons, which are Schwann cells and oligodendrocytes. Knowing this, you then need to apply your knowledge of the difference between oligodendrocytes and Schwann cells and their functions. Oligodendrocytes are cells that myelinate axons in the central nervous system while Schwann cells serve the same purpose in the peripheral nervous system. Therefore, the function of Schwann cells is affected by the PMP22 gene. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, good job! If not, where did you go wrong? Did you remember that oligodendrocytes are found in the central nervous system and not the peripheral nervous system? Did you remember that Schwann cells are responsible for myelination of peripheral nerves and that myelination increases the Version 1
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conduction of action potentials? 78.4) B
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Clarify Question • What is the key concept addressed by the question? o The question is asking you to evaluate which sentence is the most logical with the context clues that are provided. • What type of thinking is required? o This question is asking you to evaluate which words most accurately fit into the sentence provided. Gather Content/Choose Answer • What do you already know about components of the nervous system? What other information is related to the question? o To solve this problem, you’ll need to apply your knowledge of the difference between oligodendrocytes and Schwann cells and their functions. Oligodendrocytes are cells that myelinate axons in the central nervous system while Schwann cells serve the same purpose in the peripheral nervous system. The first blank refers to the outcome of defects that can have different causes, but that is indistinguishable at the level of the whole organism. The word that best fits here is “symptoms”. The next blank refers to a problem with motor nerve function, so “sensory neurons” does not make sense and “somatic cells” is too vague. This leaves you with answer b, which makes sense because Schwann cells lay down myelin in motor neurons. Problems with either the motor neuron itself or its myelin would result in the same symptom, a reduction in the conduction of neural signals. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you Version 1
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astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, good job! If not, where did you go wrong? Did you remember that oligodendrocytes are found in the central nervous system and not the peripheral nervous system as Schwann cells? Did you remember that Schwann cells are responsible for myelination of peripheral nerves and that myelination increases the conduction of action potentials? Did you understand the concept that multiple genotypes and defects can lead to the same symptoms? Did you use the process of elimination to discount answers with incorrect words? 78.5) A
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Clarify Question • What is the key concept addressed by the question? o The question is asking you to evaluate the cause of muscle degeneration following motor neuron degeneration in CharcotMarie-Tooth disease. • What type of thinking is required? o This question is asking you to evaluate the cause of muscle degeneration in Charot-Marie-Tooth disease following motor neuron degeneration. Gather Content/Choose Answer • What do you already know about components of the nervous system? What other information is related to the question? o To solve this problem, you’ll need to apply your knowledge of what happens to muscles when they are inactive for long periods of time and the cause of Charcot-Marie-Tooth disease. Although not discussed directly in this chapter, you are probably aware that muscles atrophy and weaken when they are not used. CharcotMarie-Tooth disease produces a loss of motor neurons and/or their function. As motor neurons control muscle contraction, if motor neurons degenerate, then muscles with atrophy over time. Thus, the answer is a. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, good job! If not, where did Version 1
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you go wrong? Did you remember that motor neurons control muscles? Did you forget that fMRI is a brain scanning technique and EKG a heart monitoring technique? While muscles can contain large numbers of mitochondria, and Charcot-Marie-Tooth disease can be caused by clumping of mitochondria in motor neurons, the question does not provide information that states that such clumping occurs in muscle cells. 78.6) [C, F, G, H]
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Clarify Question • What is the key concept addressed by the question? o The question is asking you to recommend clinical tests for a disease. • What type of thinking is required? o This question is asking you to evaluate the causes and consequences of Charot-Marie-Tooth disease. Gather Content/Choose Answer • What do you already know about components of the nervous system? What other information is related to the question? o To solve this problem, you’ll need to apply your knowledge about the causes and consequences of Charcot-Marie-Tooth (CMT) disease. CMT is caused by mutations in PMP22 and MFN2 proteins, which leads to demyelination and degeneration of motor neurons. This degeneration leads to lack of muscle activation and muscle atrophy and weakness. The first answer is incorrect because oligodendrocytes are not found in the motor neurons that are affected by CMT. The second answer is incorrect because EKG are used to record heart rhythms and not skeletal muscle contraction. As, CMT causes muscle weakness, EMG would be an appropriate test. The fMRI tests would be inappropriate as they are measuring brain activity and not muscle activity. Genetic testing for PMP22 and MFN2 would be sensible since both genes have been implicated in CMT. Looking for signs of demyelination or decreased nerve conduction would also be appropriate. Reflect on Process • Did your problem-solving process lead you to the correct Version 1
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answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, good job! If not, where did you go wrong? Did you remember that CMT is a disease caused by motor nerve degeneration that results in muscle weakness? Did you forget that fMRI is a brain scanning technique and EKG a hear monitoring technique? Did you forget that oligodendrocytes are only found in the central nervous system and not the peripheral nerves (like motor nerves)? 79) Section Break 79.1) D
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Clarify Question • What is the key concept addressed by the question? o The question is asking you to solve which ion is responsible for hyponatremia. • What type of thinking is required? o This question is asking you to analyze the potential negative consequences of drinking too much water on cellular function. Gather Content/Choose Answer • What do you already know about components of the nervous system? What other information is related to the question? o To solve this problem, you’ll need to remember what the relative concentrations of important ions are across the cell membrane. Most of the cell is composed of hydrogen and oxygen in the form of water or other molecules, but these are not the ions responsible for neural signaling. Remember that the concentration of sodium is much greater outside the cell than inside, and the opposite is true for potassium. Since the question states that drinking too much can upset the ion balance in the extracellular space, you can surmise that the extra water will dilute the ions in the extracellular space, decreasing the concentration of ions outside the cell. Since sodium is usually greatest outside the cell, diluting it would disrupt the gradient which usually results in sodium rushing into the cell, which is the basis of action potentials. If there is no gradient due to hyponatremia, no action potentials! Also, diluted extracellular fluid can lead to water coming into your cells (via osmosis) and causing cells to swell. Reflect on Process Version 1
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, good job! If not, where did you go wrong? Did you think it was potassium? Too little potassium can result in muscle cramps in runners, but the question mentioned the ion balance in the extracellular space and the ion of greatest concentration there is sodium. While the concentration of calcium ions is also greater outside the cell than inside the cell, it is much smaller than that of sodium. 79.2) A
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Clarify Question • What is the key concept addressed by the question? o The causes and consequences of hyponatremia. • What type of thinking is required? o The question is asking you to analyze the effects of marathon running on the risk of hyponatremia. Gather Content/Choose Answer • What do you already know about hyponatremia? What other information is related to the question? o To solve this problem, you’ll need to remember that hyponatremia is low blood sodium. Running on a hot day increases sweating, not urination, and sweat contains significant amounts of sodium. Increased sweating increases the risk of hyponatremia. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, good job! If not, where did you go wrong? Did you think that athletes lose too much potassium in sweat? That is true, but the prequestion paragraph explains that hyponatremia is referring to low sodium, not low potassium. 80) Section Break 80.1) A 80.2) A 81) Section Break
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81.1) D
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Clarify Question • What is the key concept addressed by the question? o Sodium and potassium ion flow. • What type of thinking is required? o This is an analyze question because you have to consider the normal distribution of ions across a cell membrane, and then predict the result of free movement of these ions. Gather Content/Choose Answer • What do you already know about sodium and potassium? What other information is related to the question? o To solve this problem, you’ll need to understand that sodium normally has a greater concentration outside the cell and potassium has a greater concentration inside the cell. If a channel is locked open, this would allow free flow of sodium and potassium. Sodium will rush into the cell, and potassium will rush out of the cell, down their concentration gradients. This would reduce the ionic gradients and prevent the formation of action potentials leading to paralysis. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, good job! If not, where did you go wrong? Did you remember that the distribution of sodium and potassium across the cell membrane are opposite of each other, and that sodium has a greater concentration outside of the cell, whereas potassium has a greater concentration inside the cell. Did Version 1
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you recall that ions always flow down their electrochemical gradients? 81.2) C
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Clarify Question • What is the key concept addressed by the question? o Sodium and potassium ion flow and equilibrium. • What type of thinking is required? o This is an analyze question because you have to consider the normal distribution of ions across a cell membrane, and then predict the result of free movement of these ions. Gather Content/Choose Answer • What do you already know about sodium and potassium? What other information is related to the question? o To solve this problem, you’ll need to understand that sodium normally has a greater concentration outside the cell and potassium has a greater concentration inside the cell. If a channel is locked open, this would allow free flow of sodium and potassium. Sodium will rush into the cell, and potassium will rush out of the cell, down their concentration gradients. This would reduce the ionic gradients and prevent the formation of action potentials (caused by sodium rushing into the cell) leading to paralysis, as well as prevent the maintenance of the resting membrane potential (which is largely caused by the equilibrium potential of potassium). Resting membrane potential is negative (usually about -60 to -70 mV), because there are more positively charged ions inside the cell than outside. Although leaky potassium channels allow a small amount of potassium to flow out of the cell continually, having sodiumpotassium channels locked open would allow potassium to flow out rapidly, which would increase the resting membrane potential (i.e., make it less negative).
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, good job! If not, where did you go wrong? Did you remember that the distribution of sodium and potassium across the cell membrane are opposite of each other, and that sodium has a greater concentration outside of the cell, whereas potassium has a greater concentration inside the cell. Did you recall that ions always flow down their electrochemical gradients? Did you recall that action potentials are “all-or-none” responses such that larger depolarizations would not be possible (answer D)? Also, did your remember that the sodium-potassium pump requires energy in the form of ATP? If the pump is locked open, it will not be utilizing ATP and so the resting potential would require more energy to maintain (answer A), but with the channels locked open it is not able to. 81.3) C
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Clarify Question • What is the key concept addressed by the question? o Sodium and potassium ion flow and equilibrium. • What type of thinking is required? o This is an analyze question because you have to consider the normal distribution of ions across a cell membrane, and then predict the result of free movement of these ions. Gather Content/Choose Answer • What do you already know about sodium and potassium? What other information is related to the question? o To solve this problem, you’ll need to understand that sodium normally has a greater concentration outside the cell and potassium has a greater concentration inside the cell. If a channel is locked open, this would allow free flow of sodium and potassium. Sodium will rush into the cell, and potassium will rush out of the cell, down their concentration gradients. This would reduce the ionic gradients and prevent the formation of action potentials (caused by sodium rushing into the cell) leading to paralysis, as well as prevent the maintenance of the resting membrane potential (which is largely caused by the equilibrium potential of potassium). Also remember that action potentials are “all-or-none” events that do not increase in amplitude (strength), but vary in frequency. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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o If you figured out the correct answer, good job! If not, where did you go wrong? Did you remember that the distribution of sodium and potassium across the cell membrane are opposite of each other, and that sodium has a greater concentration outside of the cell, whereas potassium has a greater concentration inside the cell. Did you recall that ions always flow down their electrochemical gradients? Did you recall that action potentials are “all-or-none” responses such that larger depolarizations would not be possible (answer B)? Remember that ion gradients are necessary for the production of action potentials. If sodium can flow freely down its concentration gradient, then its gradient will be gone and there will be no force attracting it into the cell during an action potential (and thus no action potential will occur). 82) Section Break 82.1) B
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Clarify Question • What is the key concept addressed by the question? o How does botulinum toxin affect the neuromuscular junction? • What type of thinking is required? o This is an analyze question because you need to take information about the neuromuscular junction and synaptic transmission and predict clinical symptoms from a toxin. Gather Content/Choose Answer • What do you already know about the botulism? What other information is related to the question? o To solve this problem, you’ll need to know that ACh is released at neuromuscular junctions and that for a muscle cell to be activated and contract, ACh must be released by synaptic vesicles as they fuse to the pre-synaptic membrane, and then bind to ACh receptors in the post-synaptic membrane. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, good job! If not, where did you go wrong? Did you forget that neurotransmitter release at the neuromuscular junction is necessary for muscle contraction? Did you think that ACh affected all sensory neurons (answer C)? The question asked specifically about the neuromuscular junction, so you could eliminate answers C & D as they ask about sensory
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neurons and the brain in general. 82.2) C
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Clarify Question • What is the key concept addressed by the question? o What is the most harmful effect of botulinum toxin? • What type of thinking is required? o This is an analyze question because you need to take information about the neuromuscular junction and synaptic transmission and predict clinical symptoms from a toxin. Gather Content/Choose Answer • What do you already know about botulism? What other information is related to the question? o To solve this problem, you’ll need to know that ACh is released at neuromuscular junctions and that for a muscle cell to be activated and contract, ACh must be released by synaptic vesicles as they fuse to the pre-synaptic membrane, and then bind to ACh receptors in the post-synaptic membrane. Then you need to consider what the most harmful physiological effects of preventing ACh release would be. Since this toxin prevents muscle contraction (i.e., paralysis), lack of contraction in which muscles would be the most life-threatening? Probably the heart and the lungs. Since no question refers to the heart directly and only two answers refer to the lungs (respiration), one can assume that the answer is either B or C. Answer B cannot be correct because we know that botulinum toxin leads to lack of contraction, not spastic, constant contraction. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more Version 1
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desirable result? o If you figured out the correct answer, good job! If not, where did you go wrong? Did you forget that lack of ACh release prevents muscle contraction? Did you think through what the most dangerous physiological effects are (e.g., pupil dilation is not life threatening per se). Although slowed action potential conduction would be detrimental, botulinum toxin stops action potentials altogether as ACh release is necessary for action potentials. 82.3) B
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Clarify Question • What is the key concept addressed by the question? o What are the effects of tetanus toxin? • What type of thinking is required? o This is an evaluate question because you need to take information about inhibitory neurons and motor neurons and predict clinical symptoms from a toxin that disrupts the communication between the two types of neurons. Gather Content/Choose Answer • What do you already know about tetanus? What other information is related to the question? o To solve this problem, you’ll need to know that inhibitory interneurons of the spinal cord inhibit signals going to motor neurons that control skeletal muscles. If these interneurons are not functioning to regulate signals going to motor neurons, they would be firing all the time, producing continual muscle contraction (or spastic paralysis). This would not slow action potential conduction rate (answer C) but would increase the rate of action potentials going to motor neurons. Pupil dilation is controlled by the autonomic system in the brain and so is not affected by changes in the spinal cord. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, great! If not, where did you Version 1
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go wrong? Did you confuse the definitions of flaccid and spastic paralysis? Did you think that inhibitory interneurons slow down action potential conduction of motor neurons? Remember that two negatives equal a positive, so if you inhibit an inhibitor, you end up with excitation, which is what happens to motor neurons when their inhibiting interneurons are stopped. 82.4) B
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Clarify Question • What is the key concept addressed by the question? o Physiological similarities and differences between tetanus, botulinum, and strychnine. • What type of thinking is required? o This is an evaluate question because you need to compare and contrast the modes of action of tetanus, botulinum, and strychnine toxins. Gather Content/Choose Answer • What do you already know about strychnine? What other information is related to the question? o To solve this problem, you’ll need to remember that the question states that strychnine blocks glycine from binding to post-synaptic motor neurons. From the previous questions, recall that botulinum toxin acts to prevent ACh release at the neuromuscular junction and that tetanus blocks neurotransmitter release by stopping inhibitory interneurons. Glycine is also an inhibitory neurotransmitter, so if strychnine blocks an inhibitory effect, the result will be overly excitatory as is found in tetanus poisoning. Thus the symptoms of both would be spastic paralysis. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o If you figured out the correct answer, great! If not, where did you go wrong? Did you think that since both botulinum and strychnine Version 1
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toxins both affect neurotransmitters in the synaptic cleft that the symptoms would be the same (i.e., a lack of muscle contraction)? That is sensible but strychnine blocks glycine (which is inhibitory) instead of ACh (which is excitatory). Thus strychnine produces an excitatory output leading to too much muscle contraction, while blocking ACh (like botulism) produces too little muscle contraction.
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Chapter 43 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) True or false: Humans are unique among animals due to our highly-evolved repertoire of sensory receptors. ⊚ ⊚
true false
2) True or False: A single type of receptor is responsible for detecting all tactile pressure in humans. ⊚ ⊚
3)
true false
True or False: There is only a single type of pain receptor. ⊚ ⊚
true false
CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 4) Which of the following are tactile receptors? (Check all that apply.) A) Merkle cell B) ampullae of Lorenzini C) node of Ranvier D) Meissner corpuscle E) Ruffini corpuscle F) rod cell G) Pacinian corpuscle H) free nerve ending I) ganglion cell J) cone cell
5)
How is the lateral line of a fish similar to the ears of a human? (Check all that apply.)
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A) cilia embedded ina gelatinous matrix B) cochlea C) hair cells D) large externalstructures for capturing pressure waves E) line of cellsextends along length of the body F) organ of Corti G) pressure waves H) sensory neurons I) several kinocilia and one stereocilium J) severalstereocilia and one kinocilium
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 6) All sensory input arrives at the central nervous system in the same form, as ____________ propagated by afferent neurons. Perception of the type and intensity of a stimulus depends on which part of the brain the impulse projects to and the firing frequency of the sensory neuron. A) action potentials B) receptor potentials C) reflexes D) frequency localizations E) thresholds
7) The simplest sensory receptors are __________ that respond to mechanical distortion, changes in temperature, or specific chemicals. A) nociceptors B) free nerve endings C) gated channels D) photoreceptors E) ganglia
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8)
What sensory receptors sense stimuli that arise from within the body? A) gustatoryreceptors B) photoreceptors C) interoreceptors D) ampullae ofLorenzini E) exteroreceptors
9) When membrane proteins on an olfactory neuron are stimulated by the binding of a specific chemical, what is the immediate result? A) membranedepolarization B) membranerepolarization C) active iontransport D) membranehyperpolarization E) neurotransmitterrelease
10)
Which includes all of the components that make up the Organ of Corti? A) the basilarmembrane only B) the tectorial andbasilar membranes C) hair cells andassociated neurons only D) hair cells and thetectorial membrane E) hair cells and thebasilar and tectorial membranes
11) The lateral line system provides ________ with a sense of "distant touch," enabling these animals to sense objects that reflect pressure waves and low-frequency vibrations.
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A) adultamphibians B) reptiles C) birds D) mammals E) fish
12) Pit vipers are the only known vertebrates with an ability to detect a certain type of stimulus. What can these snakes sense? A) infraredradiation B) ultravioletradiation C) microwaveradiation D) visible lightradiation E) none of these
13)
What are the receptors of sharks that can detect disturbances in electrical fields called? A) Organs ofCorti B) paciniancorpuscles C) lateral linecanals D) nodes ofRanvier E) ampullae ofLorenzini
14)
Which of the following receptors does not trigger depolarization of a sensory neuron? A) mechanoreceptors B) G-proteinreceptors C) chemoreceptors D) photoreceptors E) exteroceptors and interoceptors
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15) Which correctly represents the sequence of steps involved to convey sensory information to the CNS? A) stimulation and ionflow through the synaptic cleft B) neurotransmitterrelease and interpretation C) neurotransmitter release and ion flow through the synaptic cleft D) stimulation, transduction, transmission, and interpretation E) stimulation,transmission, and neurotransmitter release
16)
Which of the following stimuli do vertebrates NOT have a specialized receptor for? A) hearing B) taste C) smell D) humidity E) vision
17) Which is NOT a stimulus that the simplest sensory receptors, free nerve endings, will respond to? A) bending of thesensory neuron membrane B) changes intemperature C) changes in theoxygen content of the extracellular fluid D) release ofodorants from freshly baked bread E) stretching of thesensory neuron membrane
18)
Which is NOT a stimulus that exteroceptors can sense?
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A) gravity B) smell C) light D) muscletension E) sound
19)
Which is NOT a stimulus that interoceptors can sense? A) limb position B) pain C) gravity D) bodytemperature E) muscle length
20)
Which of the following is NOT an example of a mechanoreceptor? A) Meissner'scorpuscles B) Ruffiniendings C) Merkel cells D) redcorpuscles E) Paciniancorpuscles
21) Cutaneous receptors are classified as interoceptors. These specialized skin receptors can respond to which of the following stimuli? A) heat, cold, andlight B) pain, pressure,and sound C) chemicals, light,and sound D) heat, cold, pain,touch, and pressure E) heat, cold, pain,pressure, light, and sound
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22) What are the receptors called that transmit impulses that are perceived by the brain as pain? A) baroreceptors B) chemoreceptors C) nociceptors D) thermoreceptors E) propioceptors
23)
Which of the following stimuli will NOT activate a nociceptor? A) extremes intemperature B) very intensemechanical stimulation C) specific chemicalsin the extracellular fluid D) chemicals releasedby injured cells E) external odorantmolecules
24) What are the sensory structures that enable invertebrates to determine the orientation of the body with respect to gravity called? A) carotid bodies B) statocysts C) Ruffiniendings D) baroreceptors E) interoceptors
25)
Which of the following do humans NOT have taste buds specialized to sense?
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A) salty B) sour C) sweet D) vitamins E) bitter
26) Which of the following are components of vertebrate gravity receptors? I-Utricle and saccule chambers of a membranous labyrinth. II-Hair cells with stereocilia and kinocilium. III-Hairlike processes embedded with otolith membrane, a gelatinous membrane containing calcium carbonate crystals. IV-Peripheral chemoreceptors. A) I and II only B) II, III, and IV C) I and IV only D) I, II, and IV E) I, II, and III
27)
Which of the following constitute the vestibular apparatus? A) saccule andutricle only B) semicircular canals, saccule, and utricle C) ampullae of Lorenzini D) saccule, utricle,and Organ of Corti E) saccule, utricle,and ventricle
28)
What does the middle ear consist of?
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A) three ossiclebones B) the ear canal C) the ear drum D) the vestibularcanal E) the tympaniccanal
29) Which sequence of events is required for the brain to interpret sound? I. Vibration of the basilar membrane relative to the tectorial membrane causes cilia on hair cells to bend and triggers depolarization. II. Hair cells stimulate the production of action potentials in sensory neurons that project to the brain. III. Ganglion cell axons transmit action potentials to the occipital lobe. A) II then I B) III then I then II C) III then I D) I then II E) I then II then III
30) Which animal became numerous and widespread by using sonar to enable a high level of activity in the dark? A) bats B) whales C) owls D) dolphins E) shrews
31)
In the vertebrate eye, what structure is light focused onto?
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A) pupil B) lens C) retina D) sclera E) iris
32)
Which is NOT a part of the vertebrate eye? A) cornea B) retina C) iris D) cochlea E) pupil
33)
In the vertebrate eye, what structure controls the amount of light that reaches the retina? A) fovea B) cornea C) iris D) lens E) sclera
34)
What is the photopigment in rod cells called? A) photopsin B) rhodopsin C) opsin D) carotene E) melanin
35)
Which of the following cells are NOT found in the retina?
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A) rods B) cones C) bipolar cells D) hair cells E) ganglion cells
36)
What are the short retinal photoreceptors responsible for color vision called? A) rods B) cones C) bipolar cells D) glial cells E) ganglioncells
37) Color blindness is caused by heritable mutations in cone photoreceptors. How many cone types does the retina of a colorblind individual typically contain? A) only one B) two C) three D) four E) five
38) What sequence of events leads to the perception of a visual scene? I. In response to light, retinal dissociates from rod and cone photopigments, hyperpolarizing the photoreceptor cells and leading to activation of bipolar neurons. II. Action potentials are propagated through ganglion cells, whose axons project to the occipital lobe of the brain. III. In response to light, rod and cone photoreceptors depolarize, causing increased release of neurotransmitter and activation of bipolar neurons.
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A) I then III B) III then II C) III then I then II D) I then II then III E) I then II
39)
What sensory equipment is required for an animal to have binocular vision? A) eyes located to thesides of the head B) forward-facingeyes C) a camera-type eyewith multiple lenses D) infraredvision E) ultravioletvision
40)
Which of the vertebrates senses is the least well understood? A) electroreception B) magnetoreception C) vision D) hearing E) touch
41)
Which is NOT an example of a stimulus sensed by an interoceptor? A) temperature B) vibration C) pain D) magnetism E) touch
42)
Choose the receptor that is NOT correctly matched with its function.
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A) proprioceptor -monitors stretch of muscle fibers B) baroreceptor -monitors hydrostatic pressure in blood vessels C) nociceptor -transmits signals that the brain interprets as pain D) chemoreceptor -perceives taste and smell stimuli E) peripheralchemoreceptor - monitors the pH of the cerebrospinal fluid
43)
Which of the following statements about the lateral line system is NOT correct? A) allows fish tosense objects based on the pressure waves they produce B) allows fish tosense objects based on the low-frequency vibrations they produce C) allows fish toswim in synchrony with a school of other members of its species D) provides the fishwith the ability to see images E) allows a blindcave fish to sense the water patterns flowing past its body
44) In what order will you encounter the following structures if you examine the human ear from the outside inward? A) tympanic membrane → malleus →incus → stapes → oval window → cochlea B) tympanic membrane → incus →malleus → stapes → oval window → cochlea C) tympanic membrane → stapes →malleus → incus → oval window → cochlea D) tympanic membrane → malleus →incus → stapes → cochlea →oval window E) tympanic membrane → oval window → malleus →incus → stapes → cochlea
45) Which animal is NOT able to use sonar as a form of "lightless vision" to navigate in dark environments? A) shrews B) owls C) bats D) whales E) dolphins
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46)
Where is the visual image in focus for a nearsighted individual? A) behind theretina B) in front of theretina C) on the retina,but it appears blurred D) at the lens,forming a shadow on the retina E) on the retina,but it is upside down
47) The human retina is composed of three cell layers. Which represents the correct order of these layers, starting with the layer that is closest to the iris? A) ganglion cells → bipolar cells → rods and cones B) optic nerve cells → rods and cones → bipolar cells C) rods and cones → bipolar cells → ganglion cells D) bipolar cells → ganglion cells → rods and cones E) rods and cones → optic nerve cells → bipolar cells
48)
Which of the following animals does NOT have electroreceptors? A) bony fish B) sharks C) duck-billplatypus D) skates E) pit vipersnakes
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49) Each type of cone cell is stimulated by a different color of light. In humans, a colorful scene is perceived as a combination of signals from three cone types. Which colors correspond to these three cones? I-Red II-Yellow III-Orange IV-Blue V-Green VI-Purple A) I, II, and III B) I, III, and IV C) I, IV, and V D) I, V, and VI E) II, IV, and VI
50)
Which of the following statements about hair cells is NOT true? A) They are found inthe mammalian ear. B) They are found inthe fish lateral line system. C) They can berepaired if they rupture. D) Bending of thecells triggers ion flow across the cell membrane. E) Their structureincludes stereocilia and a kinocilium.
51)
Which of the following structures is found in a human eye, but NOT in an octopus eye? A) retina B) lens C) optic nerve D) blind spot E) cones
52)
Which taste modality does not involve activation of a G-protein coupled receptor?
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A) bitter B) sweet C) umami D) sour E) all tastesensations involve GPCRs
53)
What effect do high frequency sounds tend to have on the ear? A) displace thewhole length of the basilar membrane with a maximum near the apex B) move only thebasal portion of the basilar membrane C) move only theapex portion of the basilar membrane D) move only theportion of the basilar membrane between the basal portion and the apex E) only move thetectorial membrane
54) The statoliths of a lobster are replaced with iron filings, and a strong magnetic field is produced at the top of its tank. How will the lobster respond? A) Its dorsal surfacewill stick to the top of the tank and it will be unable to move. B) It will turn upsidedown and grip the underside of the tank lid. C) It will turn upsidedown and remain at the bottom of the tank. D) It will not respondin any way. E) It willcontinuously spin in circles.
55)
Which of type of information is NOT communicated by proprioceptors? A) muscletemperature B) limb movement C) muscleposition D) musclecontraction E) muscle stretch
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56)
What happens to a retinal photopigment when it captures a photon? A) It releases anelectron. B) Itfluoresces. C) It changesshape. D) It begins tovibrate. E) It doesnothing.
57)
Which of the following statements regarding vision is NOT true? A) Vertebrate rods and cones hyperpolarize in response to light. B) Insects and birds can often see into the ultraviolet range. C) Bright light will often produce action potentials in both rods and cones. D) Rhodopsin isfound in the membrane of rods.
58)
Visual acuity is highest when an image is focused on what part of the retina? A) rods outside thefovea B) cones outside thefovea C) rods within thefovea D) cones within thefovea E) anywhere, as longas there is ample light
59) All of the varied sensations we experience are due to which three categories of sensory receptors? A) visioceptor,audioceptor, olfactoceptor B) exteroceptor,interoceptor, proprioceptor C) mechanoreceptor,chemoreceptor, electromagnetic receptor D) mechanoreceptor, olfactory receptor, photoreceptor E) mechanoreceptor,chemoreceptor, nociceptor
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60) What difference in axonal signaling determines whether we experience a mild or a strong sensation? A) amplitude ofaction potentials B) frequency ofaction potentials C) action potentialthreshold D) conductionspeed E) amount ofneurotransmitter released per vesicle
61) Since the optic nerve must pass through the retinal layer, we all have a blind spot devoid of light receptors. This normally goes unnoticed, since the brain attempts to compensate for missing sensory information by filling it in based on surrounding patterns. Which step of the sensory pathway is represented by perceptual filling-in of the physiological blind spot? A) interpretation B) stimulus C) transduction intoreceptor potential D) action potentialtransmission
62) What information would best help you distinguish what type of sensation a sensory neuron transmits? A) the rate of actionpotential firing B) the proteins it expresses most abundantly C) the part of thebrain it transmits signals to D) the amplitude of action potentials E) the diameter of the axon
63) What is the primary difference in how touch sensation and hearing sensation are conveyed?
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A) theneurotransmitters secreted by the sensory neurons B) the way that the axons physically connect to the brain stem C) the shape of the sensory axons D) the proteins that transduce the chemical signal in the brain E) the part of thebrain that receives the signal
64)
What is the molecular basis of touch sensation?
A) Pressure on theskin squeezes out chemical signals from epidermal glands. B) Cell membranedistortion opens touch receptors, creating a receptor potential. C) Pressure damages the delicate strands of skin cell DNA, activating a complex signalling cascade. D) Pressure on sensory axons bursts vesicles and causes neurotransmitter release.
65) Pain receptors are activated by tissue damage, but pain perception requires intact, functional neurons. How does this work? A) Nociceptor neuronshave special membrane repair mechanisms. B) The nociceptor neuron only sends action potentials as it is dying. C) The axon continues to fire action potentials despite damage to the cell body. D) The neuron itselfdoes not need to be damaged; it responds to signals released by nearby damagedcells.
66) In "The Disembodied Lady," neurologist Oliver Sacks tells the story of a patient who suffered a catastrophic loss of sensory function. She said, "I feel my body is blind and deaf to itself. . . . It has no sense of itself." The patient's nerve damage was strikingly specific. What single type of neuron most likely suffered damage?
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A) gustatoryreceptors B) proprioceptors C) olfactoryreceptors D) Meissnercorpuscles E) rods and cones
67) Nociceptors can respond to nearby tissue damage by sensing cytosolic factors released by damaged cells. Such "algogenic agents" can cause pain sensation even in the absence of tissue damage. What might be a practical use for such an agent? A) a nonlethal riotcontrol measure B) an anesthetic drug C) a treatment for damaged tissue D) a tasty food additive
68) The discovery that ATP is a pain-signaling factor immediately suggested what possible therapeutic approach to alleviate chronic pain? A) create largeintracellular aggregates of ATP B) treat with an ATPreceptor antagonist C) block the synthesis of ATP inside cells D) use electric stimulation on pain centers of the brain
69) Mutations in the DFNA20/26 locus, which codes for the actin gamma 1 protein, are associated with congenital deafness. An irate senator complains that government money is being wasted on studies of this mutant gene -- in yeast! "I am no biologist," says the senator, "but I am pretty sure yeast don't have ears." How do you respond?
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A) "You areright, Senator -- yeast do not have ears. We should revoke the fundingimmediately." B) "We can learnvaluable information about the structure of the mutant protein by expressing itin yeast. It is difficult to collect large amounts of actin from tiny haircells, and unethical to collect it from human patients." C) "We can learnvaluable information about the transcription of the mutant gene in yeast. It ismuch more difficult to study transcription in human cells." D) "We can learnvaluable information about sound transmission through the mutant yeast. Byplacing a speaker against a yeast vial and recording sound from the other side,we can infer how the mutant actin affects sound waves."
70) As CO2 builds up in the atmosphere it also accumulates in the oceans, causing acidification. This poses a challenge to marine creatures that rely on calcium carbonate deposition such as corals, mollusks, and even fish, which use it to form otoliths. Researchers investigated whether otolith deposition was impaired at low pH, and were surprised to find that otoliths were actually larger in this condition. This means that, while coping with global climate change, at least fish will still be able to maintain which sense(s)? A) feeling pain B) vision C) taste D) olfaction E) hearing andbalance
71)
What are the categories of taste sensation? A) sweet, salty,sour, creamy, umami B) sweet, sour,salty, bitter, umami C) sweet, salty, bitter, chocolate, coffee D) sweet, sour, salty, creamy, savory
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72) You make a knockout of a gene involved in neurological development, and find that the mice have malformed semicircular canals. Instead of being orthogonal (at right angles) to each other, they are parallel. What aberrant behavior might you see in these mice? A) overeating B) falling over C) not startling tosudden noise D) unable to respondto a call to locate another mouse E) low muscletone
73) In 1908, chemist Kikunae Ikeda identified a new taste modality he called "umami", or "delicious" in Japanese. It gives a savory flavor to meat, seaweed, and tomatoes. What molecule is responsible for umami? A) Na+ions B) H+ions C) glutamate D) Mg+2ions E) Fe+2ions
74) Beta-N-Methylamino-L-Alanine, or BMAA, is a glutamate receptor agonist produced by cyanobacteria. Since Glu is an excitatory neurotransmitter, it is not surprising that BMAA is associated with neurological damage. Buildup of BMAA in fruit bats was hypothesized to cause neurodegenerative disease in islanders that fed on the bats. A recent study found high levels of BMAA in sharks, suggesting that consumption of shark fin soup is also dangerous. The researchers suggested that a secondary effect of BMAA may actually make these hazardous foods surprisingly desirable. What might this be?
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A) Since BMAA is aGlu receptor agonist, it promotes incorporation of Glu into proteins, and hashealth-promoting effects. B) Since BMAA is derived from cyanobacteria, it provides unique nutrients not found in the animal or plant kingdom. C) Since BMAA is aGlu receptor agonist, it imparts a strong umami flavor that makes food moredelicious. D) Since BMAAcontains alanine, it improves protein synthesis by providing this rarenutrient.
75)
Which sensory modality responds to the broadest range of molecules? A) TRP channels B) Taste C) Smell D) Vision E) Touch
76) Researchers studying olfactory and taste receptors have stumbled upon an unusual phenomenon. These receptor proteins are sometimes expressed in other animal tissues in addition to the nose or tongue. For example, the sweet taste receptor T1R2 is expressed in the pancreas. Suggest the best possible explanation for these findings. A) Damaged receptorsare recycled by the body and end up in waste-disposal organs. B) Control ofprotein expression is imperfect. As long as a receptor doesn't interfere withorgan function, expression will not be selected against. C) Chemoreceptorsbind molecules that help the body sense and respond to internal phenomena, suchas sugar levels in the blood. D) Techniques used to visualize protein expression are imperfect and may lead to false positive results.
77)
What statement best summarizes the evolutionary history of eyes?
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A) Developmentof light-sensing organs evolved once, but several eye structures evolvedseparately. B) Eyes evolved once and were slightly modified in different phyla. C) Eyes evolved separately in each phylum from an ancestor with no ability to detect light. D) Light-detection organs can develop with very little developmental constraint.
78) Peripheral shadows or flashes of light can be a sign that the retina is peeling away from the layer below. Why is detachment of the retina a medical emergency? A) It contains thephotoreceptor cells that respond to light. B) It is crucial forfocusing the image. C) It secretes tearsthat bathe and protect the eyeball. D) It is a sphinctermuscle that controls light transmission.
79) After your eye exam, the optometrist breaks the bad news: "Your lens is a little too flat, and as a result it is focuses the image just in front of your retina." What kind of vision do you have? A) astigmatism B) nearsighted C) farsighted D) night-blindness
80)
Why are carrots said to be good for you?
A) That is just anold wive's tale. B) Beta-carotene,the orange pigment in carrots, is a precursor to Vitamin A and retinal, thecofactor in photopigments. C) Beta-carotene, the orange pigment incarrots, is necessary to form lens proteins. D) Carrots have large amounts ofglutamate, a neurotransmitter that activates sensory neurons.
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81) At night, faint objects are best seen when not looked at directly. What is the basis of this phenomenon? A) Rhodopsin istransported away from the fovea at night. B) Cis-retinalbuilds up in the fovea at night, and is degraded during the day. C) Cone photoreceptorsare most sensitive in dim light, and few cones are present in the fovea. D) Rod photoreceptorsare most sensitive in dim light, and few rods are present in the fovea.
82) The ampullae of Lorenzini are jelly-filled pores that allow fish to sense electromagnetic currents. What is an important property of the jelly in these organs? A) It secretespheromones for conspecifics. B) It is a goodelectrical conductor. C) It containsgustatory receptors. D) It is an electrical insulator.
83) A research strain of mice has a mutation that causes voltage-gated sodium channels to take longer to return to the active state after a spike. What is the likely consequence for transduction of sensory stimuli? A) There will be noeffect on sensory perception, because sensory information relies onstimulus-gated ion channels and not voltage-gated ion channels. B) Sensory informationwill be incorrectly perceived as high intensity stimuli, due to the increasedfrequency of action potentials. C) The mutation willinterfere with the ability of stimuli to create receptor potentials,and thus the neuron will fire with slow, broad action potentials,giving the animal enhanced sensory perception. D) Due to a longerrefractory period, the neuron will be unable to conduct high frequency actionpotentials, and thus will not effectively transmit information about strongstimuli.
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84) Which of the following statements would explains the importance ofPax gene families in animals? A) Pax genes are believed to grow legs in fruit flies. B) Pax genes are needed to form chemoreceptors in animals. C) Pax genes are completely unrelated and found in a variety of animals by coincidence. D) Pax gene families are found in a variety of animal phyla and help to show the evolutionary relationship of eye development.
SECTION BREAK. Answer all the part questions. 85) Vision differs from the other senses in two interesting ways. Although most sensory receptor neurons are depolarized when the receive a stimulus, rod and cone cells become hyperpolarized when they receive light. When hyperpolarized, they stop releasing inhibitory neurotransmitter and allow the bipolar cells to fire. A second unusual aspect is that the vision circuit seems to be organized "backwards" -- the light must pass through the layers of ganglion and bipolar cells to reach the rods and cones.
85.1)
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A) A B) B C) C D) D E) All of the directions are possible.
85.2)
When a cone cell is stimulated by light, what will occur at the cell membrane?
A) excitation B) inhibition C) an actionpotential D) hyperpolarization E) depolarization
86) Choose the letter that best describes the function of each receptor type. (You may use a letter more than once.) A. tonic receptors located near the surface of the skin B. pressure sensitive receptors deep in the subcutaneous layer C. receptors on the face and fingertips sensitive to light touch
86.1)
Pacinian corpuscle
86.2)
Merkle cell
86.3)
Ruffini corpuscle
86.4)
Meissner's corpuscle
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87) Honeybees have an incredible ability to distinguish thousands of different odorant molecules, using their large repertoire of olfactory receptors. A wide variety of different types of chemicals can be detected as odorants -- they simply require olfactory neurons with a receptor that can bind the chemical and transduce that stimulus into a receptor potential.
87.1) Because small quantities of powerful explosives can be hidden easily, a sensor that could detect trace amounts of illicit chemicals would be a useful tool. What animal sensory modality is exquisitely sensitive to minute quantities of airborne chemicals? A) olfaction B) taste C) vision D) hearing E) touch
87.2) Honeybees can detect a variety of odorants through olfactory receptors on their antennae. You genetically engineer a receptor to be gated by the explosive chemical TNT, and use a transgene to express the receptor in honeybee olfactory neurons. What would this provide to the bee? A) the ability to taste TNT B) it would have no effect C) the ability to smell TNT D) the abilityto collect TNT molecules E) the ability to see TNT
87.3) If genetically engineered bees could express a receptor for TNT in their olfactory neurons, what type of receptor would the TNT receptor be?
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A) chemoreceptor B) mechanoreceptor C) electromagnetic receptor D) it is a novel type of receptor
87.4) If genetically engineered bees could express a receptor for TNT in their olfactory neurons, how would the bees respond to the presence of TNT? A) It would ignorethe stimulus. B) It would be attracted. C) It would be repelled. D) It would depend onwhich olfactory neuron expresses the transgene.
87.5) If genetically engineered bees could express a receptor for TNT in their olfactory neurons, how could the transgenic bees be useful for detecting explosives? A) Watch for death ofthe bee when the neuron absorbs TNT. B) Use MRI to monitor the brain activity of the bee. C) Train bees torespond in a predictable way when the TNT neuron is activated by conditioningthem to expect an associated food reward. D) Grind up the bee'santennae for use in a TNT ELISA assay.
88) TRP channels normally act as temperature sensors in the body -- they are stimulus-gated ion channels, each specialized to open at various temperature thresholds. However, different TRP channels can also be gated by certain molecules such as capsaicin or menthol.
88.1)
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Why do we perceive chili peppers as "hot" and peppermint as "cold"?
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A) It is a culturalconvention to speak of chili peppers as hot and peppermint as cold. B) Capsaicin andmenthol act as agonists of TRP channels normally activated by temperaturechanges. C) We are conditioned to think so because chili-containing foods are served hot, while mint-containing foods are served cold. D) Neurons sensitiveto heat or capsaicin project to nearby regions of the brain, while neuronssensitive to cold or menthol project to other adjacent regions. E) Capsaicin transmits infrared energy, while menthol absorbs it.
88.2) What is the most likely hypothesis for the presence of TRP channel agonists in plants? A) to speed up orslow down chemical reactions in the plant B) to warm or cool the plant, depending on the season C) to discouragefeeding by herbivorous insects or mammals D) to encourage human cultivation
88.3) You decide to perform an experiment to test this why plants possess TRP channel agonists. You first set up batches of plants in the field WITH or WITHOUT applied capsaicin or menthol. What parameter do you then measure? A) photosyntheticrate B) amount of leaf orfruit damage C) metabolic rate D) palatability tohumans
89) Hair cells are delicate sensors of sound, movement, and gravity. Since they are stimulated by movement of the stereocilia and kinocilium, these structures are vulnerable to damage when stimulus is too strong or sustained.
89.1) After years of listening to loud music on headphones, the cilia on Bob's hair cells are damaged. What is the result? Version 1
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A) vestibularproblems B) hearing loss C) vision problems D) taste hallucinations
89.2) If the cilia on Bob's inner ear hair cells are damaged, what can be done to improve Bob’s hearing, other than a hearing aid? A) transgenicexpression of a cilia protein B) minoxidiltreatment C) injection ofmicrotubules into the cochlea D) not much – thereis currently no drug that can regenerate hair cells
90) Hair cells are delicate sensors of sound, movement, and gravity. They are stimulated by movement of the stereocilia -- which are actually microvilli -and the single kinocilium, which is a true cilium.
90.1) One patient at your audiology clinic has an actin defect, and another patient has a microtubule defect. How might these defects affect the function of their hair cells in hearing? A) Neither actin normicrotubule mutations will disrupt hair cell cilia function. B) Only the actin mutation will affect hair cell cilia function. C) Only the microtubule mutation will affect hair cell cilia function. D) Both can createproblems in hair cell cilia function.
90.2) One patient at your audiology clinic has an actin defect, and another patient has a microtubule defect. What sense other than hearing may be affected in these patients?
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A) smell B) taste C) balance D) touch E) proprioception
91) Unlike sweet, salty, sour, or umami, the "bitter" category of tastants includes wide structural variety of detected molecules. Multiple receptors are required to sense the different bitter tastants. What do they have in common? Bitter taste is thought to have evolved as a warning system for toxic compounds.
91.1) The bitter receptor hTAS2R38 is activated by glucosinolates found in plants such as turnips and broccoli. The gene variant a person has determines how sensitive their neurons are to these compounds. What would you predict for people who have the highsensitivity variant of hTAS2R38? A) They will noteasily digest turnips and broccoli. B) They will have to eat more turnips and broccoli to get the same flavor. C) They will disliketurnips and broccoli. D) They will become allergic to turnips and broccoli.
91.2) The bitter receptor hTAS2R38 is activated by glucosinolates found in plants such as turnips and broccoli. Glucosinolates can block synthesis and transport of iodine. Before the advent of iodized salt, this was a particular problem in areas of the world that are naturally low in iodine. Why might the human population include different variants of the hTAS2R38 gene?
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A) Areas of highiodine are generally coastal, and turnips and broccoli are not easily grownthere. B) Iodine created mutations in the hTAS2R38 gene. C) Where iodine was low, eating plants rich in glucosinolates helped people metabolize iodine, but where iodine was high they avoided such foods. D) Where iodine waslow, it was important to avoid foods with glucosinolates, but where iodine wasplentiful, palatability of a wider range of plants was beneficial.
92) Pax6 is a transcription factor noted for its unique role in specifying eye development across the animal kingdom. A homologous gene known as eyeless specifies eyes in Drosophila, and misexpression of mouse Pax6 can cause ectopic eyes in flies! This creates a quandary -- how can we explain the universality of the master regulatory gene for eye development, with the striking variability of eye anatomy in different phyla?
92.1) Misexpression of the Pax6 gene was shown to promote eye development in both vertebrates and invertebrates. The authors of this study suggested that this was evidence that eyes evolved only once. What other evidence contradicts this view? A) Invertebratesnormally have only simple eyespots. B) Many different transcription factors can initiate eye development when misexpressed. C) While the anatomy of all animal eyes is the same, lens proteins vary greatly. D) The anatomicalstructure of insect, mollusk, and vertebrate eyes are quite different.
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Answer Key Test name: Chap 43_13e_Raven 1) FALSE 2) FALSE A variety of specialized receptors detect different degrees of pressure at different levels in the skin. 3) FALSE Activation of multiple types of receptors can be interpreted as "pain" especially with unusually high degrees of activation. 4) [A, D, E, G, H] 5) [A, C, G, H, J]
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Clarify Question What is the key concept addressed by the question? • Similarities between the ear and the lateral line. What type of thinking is required? o This is an analyze question because you have to break the inner ear and the lateral line system into its separate components in order to look for commonalities. Gather Content What do you already know about the lateral line and inner ear? What other information is related to the question? • You already know that the inner ear of humans detect pressure waves of sound in the air and the lateral line of fishes detect pressure waves in the water. Both systems have sensory hair cells that convert mechanical movement into a neural signal. In both systems the mechanical movement is transferred from the surrounding environment via a gelatinous membrane (the cupula in the lateral line and the tectorial membrane in the cochlea). Sensory hair cells have one longer kinocilium and multiple, shorter stereocilia. When these cilia bend, it opens up ion channels that depolarize the cell. This signal is then sent to the sensory neurons of the auditory or lateral line nerves and then processed by the brain. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Both the lateral line and inner ear have sensory hair cell stereocilia that are embedded in a gelatinous matrix (the cupula in the lateral line and the tectorial membrane in the inner ear). These hair cells have one Version 1
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kinocilia and multiple stereocilia. These hair cells are innervated by sensory neurons in both systems. While mammals have a cochlea and an organ of Corti in the middle of it, fish do not. Similarly, while mammals have large external structures for capturing pressure waves (i.e., like pinna of the external ear), fish do not have external ears. Fish, on the other hand, have a lateral line system along the length of their body to detect vibrations and pressure waves in the water, while mammals have no need for such a system since they detect pressure waves in the air which vibrate the tympanum. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended upon your ability to pick out similarities and differences between the inner ears of humans and the lateral line of fishes. If you answered incorrectly, what went wrong? Did you remember that both systems have sensory hair cells that are mechanotransducers that convert a vibratory signal into a neural one? Did you think that since the cochlea and organ of Corti are part of the inner ear, and you knew that fish had inner ears, that fish also have these structures? Did you realize that both the cupula of the lateral line system and the tectorial membrane of the cochlea are gelatinous membranes? 6) A 7) B 8) C 9) A 10) E 11) E 12) A Version 1
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13) E 14) D 15) D 16) D 17) D 18) D 19) C 20) D 21) D 22) C 23) E 24) B 25) D 26) E 27) B 28) A 29) D 30) A In fact, bats represent 20% of living species of mammals! 31) C 32) D 33) C 34) B 35) D 36) B 37) B 38) E 39) B 40) B 41) D Version 1
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42) E 43) D 44) A 45) B 46) B 47) A 48) E 49) C 50) C 51) D 52) D 53) B 54) B
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Clarify Question What is the key concept addressed by the question? • The role of statoliths. What type of thinking is required? o This question is asking you to evaluate the effect of manipulating the lobster’s statocyst organ with iron filings. Gather Content What do you already know about statoliths? What other information is related to the question? • Statoliths are calcium carbonate crystals that are embedded at the top of invertebrate statocyst organs to act as weight bearing structures that are acted upon by gravity. Statocysts are composed of sensory hair cells embedded in a gelatinous mass. The statoliths sit on the gelatinous mass.When the lobster tilts, the statoliths tilt with it and this deflects the cilia of the hair cells. If the statoliths were replaced with iron filings, then those iron filings would be attracted to a magnetic field. If that magnetic field was placed at the top of the tank, the filings would be attracted to the direction of the top of the tank. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Normally, with the lobster flat on the bottom of its tank, the weight of the statoliths would be pulled directly down by gravity on the hair cells of the statocyst, neither deflecting them to the left or right. If a magnetic field was produced from the top of the tank, it would pull the filings upward away from the hair cells.This would provide the sensation that lobster was upside down. If the lobster gripped the underside of the top Version 1
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of the tank, the iron filings would then put pressure on the hair cells as if the statoliths were pushing down on the hair cells in the lobster’s normal position flat on the bottom of the tank. Thus, the answer would be the lobster will turn upside down and grip the underside of the tank lid. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended on your ability to weigh and judge, or evaluate, which different potential orientations of the lobster in response to a magnet reversing the normal gravitation pull on the statocyst organ. If you got an incorrect answer, did you remember that gravity normally pulls down on statoliths, pushing them against the hair cells of the statocyst organ, and that replacing statoliths with iron filings and applying a magnetic field above would produce the opposite force (taking pressure off the hair cells). If you chose the dorsal surface would stick to the top of the tank, you probably thought that the iron filings would be attracted to the magnetic field. You are correct in that the iron filings would be attracted to the magnetic field, but the small amount of iron filings that one could fit into a statocyst organ would not be great enough to lift the weight of a whole lobster. If you chose that it would turn upside down and remain at the bottom of the tank, you realized that the pressure on the hair cells would be opposite and so the lobster’s orientation would also be opposite, which is correct, but the lobster would be drawn to the source of the magnetic field, which is at the top of the tank and not the bottom. 55) A 56) C 57) C Version 1
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58) D 59) C 60) B
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Clarify Question What is the key concept addressed by the question? • How is strength of axonal signaling coded in the nervous system? What type of thinking is required? o This is an analyze question because you have to break neural signaling into different stages and understand which aspects of axonal signaling vary with signal strength. Gather Content What do you already know about axonal signaling? What other information is related to the question? • You already know that signals are transmitting down axons via action potentials. But what makes one signal stronger than another one? You know that action potentials are an “all-or-none” response. Once membrane potential reaches a certain threshold, then voltage-gated ion channels open up and an action potential occurs. The amplitude of the action potential does not change with increased stimulation, but the rate at which action potentials fire does change- with higher frequency of action potentials resulting from stronger stimuli. Once action potentials reach the end of the axon, neurotransmitters are released that bind to post-synaptic receptors, which can change the membrane potential and initiate an action potential in the post-synaptic neuron. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since action potentials are all-or-none responses that do not vary in amplitude or threshold, you can eliminate amplitude and threshold as correct responses. Similarly, conduction speed and the amount of Version 1
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neurotransmitter released per vesicle is constant for an individual neuron. That leaves frequency of action potentials as the correct answer. Greater stimulation leads to a higher frequency of action potentials. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended not only on distinguishing between different properties of neurons and action potentials, but on your ability to analyze which characteristics are constant and which one would shift with intensity of stimulation. If you got an incorrect answer, did you remember that action potentials are an all-or-none event that either happens or it does not, with the threshold and amplitude being constant for a particular neuron? Did you forget that axon conduction speed is dependent upon axon width and whether it is myelinated or not? Did you realize that the amount of neurotransmitter in each vesicle is constant? 61) A
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Clarify Question What is the key concept addressed by the question? • Why do we not notice our blind spot? What type of thinking is required? o This is an analyze question because you have to break sensory (visual) signaling into different stages and understand which aspects would be responsible for the lack of perception of a blind spot. Gather Content What do you already know about retinal signaling? What other information is related to the question? • You already know that the sensory perception of vision starts with photons of light activating photoreceptors in the back of the retina. Then receptor potentials lead to action potentials transmitted to the optic nerve, and then to the visual cortex of the brain. The part of the retina in which the optic nerve passes through does not have any photoreceptors and is referred to as the blind spot. Thus, any light that hits the blind spot will not be detected since there are no photoreceptors to detect it. The brain will receive no stimulation from that area of the visual field. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • If you were to order the answers in terms of the process of the visual pathway, the order would be first stimulus (which is light), then transduction into receptor potentials, which are then converted to action potentials (if the receptor potentials are great enough), and finally the action potentials are sent to the brain (visual cortex) where they are interpreted. There is nothing wrong with the first step, stimulus, because Version 1
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the light still shines on the back of the retina even if there are no photoreceptors to receive the signal in the blind spot, so the answer is not stimulus. If there are no photoreceptors to receive the light signal in the blind spot, then no transduction of receptor and action potentials will be possible from the blind spot. Thus, the brain will not receive any information from the retina about the area of the blind spot. The brain fills-in the perception of a blind spot based on visual information surrounding the blind spot via higher processing and “interpretation” of the whole visual field. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended not only on understanding the steps of the sensory pathway of visual processing , but on your ability to determine which aspects of this pathway is responsible for filling-in the perceptual gap produced by the blind spot. If you got an incorrect answer, did you realize that “interpretation” was referring to higher visual processing in the brain? Did you understand that there would be a lack of receptor and action potentials from the blind spot causing a perceptual hole, not filling in this gap? 62) C
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Clarify Question What is the key concept addressed by the question? • How to determine sensory modality. What type of thinking is required? o This question is asking you to weight and judge, or evaluate, traits that might vary by sensory modality. Gather Content What do you already know about sensory neurons? What other information is related to the question? • You already know that sensory neurons either detect stimuli or are connected to sensory receptors that do. Axons from sensory neurons then enter the dorsal roots of the spinal cord before sending their signals on to the brain. The area of the brain that the signals get sent to depends upon which sensory system is involved. Visual information gets sent to the visual cortex in the occipital lobe. Somatosensory information gets processed in the parietal cortex. Hearing is processed in the temporal lobe. Commonalities of all sensory neurons are that they all fire action potentials and the frequency of action potentials codes for intensity of sensory stimulation. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Let us evaluate each answer individually. First, rate of action potential firing encodes the strength of sensory stimulation in all sensory modalities, so it would not be a good means of distinguishing between different types of sensation. Second, the proteins that are expressed most abundantly.It is true that different sensory systems utilize different Version 1
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neurotransmitters and thus may express proteins for different receptors, but there is also an overlap between neurotransmitters utilized, and proteins expressed, in different sensory systems so you could not distinguish between sensory modalities using this alone. The part of the brain that a sensory neuron sends signals to is unique for each sensory system, so this is the correct answer. The amplitude of action potentials do not vary by sensory system. It is true that some sensory systems have sensory neurons that differ in morphology. For example, some pain fibers are thin and unmyelinated while other somatosensory neurons are myelinated and have a thicker diameter. Thus, it would be hard to determine if a sensory neuron belonged to the somatosensory system by the diameter of the axon alone. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended on your ability to weigh and judge, or evaluate, which different characteristics of sensory neurons. If you got an incorrect answer, did you remember that different regions of the brain process different sensory information, or that all sensory systems use frequency coding? Did you have trouble weighing the merits of differential protein expression relative to unique parts of the brain for different sensory systems to determine the correct answer? 63) E
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Clarify Question What is the key concept addressed by the question? • Differences between hearing and touch sensation. What type of thinking is required? o This is an analyze question because you have to break sensory (touch and hearing) signaling into different stages and decide which aspects differ between touch and hearing. Gather Content What do you already know about sensory signaling? What other information is related to the question? • You already know that touch and hearing are similar in that they both utilize mechanoreceptors. When these mechanoreceptors are activated, they release neurotransmitters in both sensory systems. The mechanism of transmitting action potentials from sensory neurons to the brain is similar in both touch and hearing, but touch signals are processed in the parietal lobe while hearing signals are processed in the temporal lobe of the brain. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • If we analyze the first four answers, we find traits that are similar between all sensory systems. In each, neurotransmitters are secreted by the sensory neurons, the axons travel through the brainstem, the sensory neurons all have a similar shape, and the proteins that transduce the chemical signal in the brain (i.e., neurotransmitters). It is true that different sensory neurons can use different neurotransmitters, but is this a primary difference in how touch and hearing sensation are conveyed Version 1
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to our brain? A greater difference would be where the information is conveyed to in the brain. Touch information is processed in the temporal lobe and hearing is processed in the temporal lobe. Thus “the part of the brain that receives the signal” would be the most correct choice. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended not only on understanding the steps of the sensory pathway of touch and hearing, but on your ability to determine which aspects of this pathway is responsible for the greatest differences in how these signals are conveyed to the brain. If you got an incorrect answer, did you fail to focus on the term primary difference in the question? Did you remember that different sensory systems are conveyed to different locations in the brain? 64) B 65) D
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Clarify Question What is the key concept addressed by the question? • How do pain receptors work if they sense damage? What type of thinking is required? o This is an analyze question because you have to break down the process of pain detection by nociceptors. Gather Content What do you already know about pain receptors? What other information is related to the question? • You already know that pain reception uses nociceptors that detect tissue damage, but how do they work. When tissue is damaged, such as a cut in the skin, an inflammatory response occurs in the tissue that releases signaling molecules such as bradykinin, prostaglandins, and a molecule called Substance P. These substances can diffuse to surrounding tissue that is not damaged and has fully functioning neurons. The molecules can affect ion movement in and out of the free nerve endings used to detect pain. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Nociceptor neurons do not have special membrane repair mechanisms, so that answer is not correct. Nociceptors need to be alive and healthy in order to send action potentials, so the answer that says the neurons only send action potentials as it is dying does not make sense. If the cell membrane of the neuron’s cell body is ruptured, then action potentials would not be possible as the ion gradient across the membrane would be lost, thus that answer is not likely. That leaves only one answer, which is Version 1
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that the neuron itself does not need to be damaged, but it responds to molecular signals released by nearby damaged cells. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended not only on understanding the steps of pain perception, but on your ability to discriminate among different potential means of how nociceptors work without being damaged themselves. If you got an incorrect answer, did you think that the pain signal associated with tissue damage only came from damaged neurons? Did you realize the molecular signals from damaged tissue could diffuse to adjacent areas to affect healthy nociceptive neurons? 66) B
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Clarify Question What is the key concept addressed by the question? • What neurons give the body a sense of itself? What type of thinking is required? o This is an evaluate question because you have to use logic to evaluate which potential sensory receptors might produce the symptoms that the patient experienced. Gather Content What do you already know about sensory receptors? What other information is related to the question? • You already know that sensory receptors send information from the environment to the spinal cord and then the brain to be processed. In all sensory receptor types except one, this information comes from the external environment. Proprioceptors provide information from within the environment of the body itself about relative position or movement of the body’s parts. If one was to loose these specific receptors, she might feel “disembodied” as she would not be able to detect herself moving. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The patient did not say she was blind or deaf, but that her body was blind and deaf to itself and had no sense of itself. Thus rods and cones, which deal with vision, is not the correct answer. Gustatory and olfactory receptors are responsible for taste and smell, respectively, and the patient did not exhibit losses in these senses. Meissner corpuscles provide information about vibrations and textures from outside the body, Version 1
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not from within the body, so this is not the correct answer. Thus, the answer must be proprioceptors, which do detect information about the body itself and its relative position and movement. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended on your ability to weigh and judge, or evaluate, which the potential sensory receptors which would cause the patients symptoms if they were lost or damaged and unable to function properly. Were you thrown off because she said her body was blind and deaf to itself, thinking it had to do with vision or hearing? Did you remember that proprioceptors are the only sensory receptor type to receive information from within the body? 67) A
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Clarify Question What is the key concept addressed by the question? • What is a use for algogenic agents? What type of thinking is required? o This is an analyze question because you have to identify key factors that qualify something as a nociceptor. Gather Content What do you already know about nociceptors? What other information is related to the question? • You already know that nociceptors are pain receptors. They are usually free nerve endings that are sensitive to noxious substances as well as tissue damage since specific cytostolic factors are released by damaged cells. Such factors, called algogenic agents, can cause a pain sensation even in the absence of tissue damage. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • What might be the practical use of an agent that would cause pain? An anesthetic drug blocks pain, so that cannot be the answer. A tasty food additive does not make much sense although capsaicin in spicy foods can produce a heat and pain sensation. There is evidence that factors that are released during damage produce vasodilation and attract white blood cells to the area and promote healing, but how could someone practically inject such agents into a wound? Since algogenic agents produce pain without injury, it makes sense that they could be used as a nonlethal riot control measure, and in fact, they are.
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended not only on understanding the function of nociceptors, but on your ability to analyze potential uses of agents that would activate them. If you got an incorrect answer, did you remember that capsaicin can produce a painful sensation, and knowing that is a component of peppers, think that a tasty food additive was the correct answer? Did you think that because cytostolic factors are released during tissue damage that they would a good treatment for tissue damage? Did you forget that anesthetics block pain instead of produce it? 68) B
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Clarify Question What is the key concept addressed by the question? • Possible therapeutic approaches related to ATP. What type of thinking is required? o This is an evaluate question because you have to use logic to evaluate which potential therapeutic approach might alleviate chronic pain. Gather Content What do you already know about pain? What other information is related to the question? • You already know that the sensation of pain is elicited by activating nociceptors. If ATP is a pain signaling factor, then this means that ATP must bind to a nociceptive receptor to open up ion channels. It also means that ATP antagonists could be used to block those same receptors and potentially block pain. You also know that ATP is the power source for the cell, so any manipulation of ATP itself inside the cell could be very dangerous. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Creating large intracellular aggregates of ATP should not have an effect of nociceptors since these receptors would be on the outside of cells. Blocking the synthesis of ATP would be harmful to the cells since ATP is their source of energy, without which, they would die. Using electrical stimulation on pain centers in the brain may or may not alleviate chronic pain, but has nothing to do with ATP being a painsignaling factor. Treating with an ATP receptor antagonist, which would prevent ATP from binding to it and sending a pain signal, is the most Version 1
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logical answer. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended on your ability to weigh and judge, or evaluate, which the potential therapeutic approaches to alleviate chronic pain. If you got it wrong, did you think that by blocking the synthesis of ATP you would prevent ATP-associated nociceptors from being bound by ATP and thus block pain? The problem with that is that nociceptors are located at the cell surface, not inside the cell, and blocking ATP production would kill the cell. 69) B
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Clarify Question What is the key concept addressed by the question? • Why study mutant actin in yeast? What type of thinking is required? o This is an evaluate question because you have to weigh the logic and content of different responses to see which would be best to answer the senator. Gather Content What do you already know about mutant genes? What other information is related to the question? • You already know that mutations are changes in the sequence of DNA that encodes a protein. Sometimes a mutation causes a significant change in the structure of a protein, leaving it nonfunctional and potentially causing disease. We know that actin is an important component of the stereocilia of hair cells that are in the inner ear, which is why a mutation in actin gamma protein 1 is associated with congenital deafness. Because yeast and human are both eukaryotes and contain similar transcription and translation machinery, human genes can be added to yeast which will then result in the yeast translating the protein of interest. In addition, there is considerable homology between yeast and human genes. As yeast can be grown rapidly and inexpensively, this is a much easier means of collecting large enough amounts of the protein to study in the lab than in mammalian systems. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The process of transcription is similar between yeast and human so it Version 1
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is not much more difficult to study transcription in human cells. The researcher is probably not interested in studying transcription per se anyway, but is interested in the function, or lack thereof, of the mutated protein. Studies sound transmission through the yeast does not make sense at all and has nothing to do with human deafness (as yeast do not have ears), but having yeast express the protein of interest is a good way to collect large amounts of the protein that would be very difficult to obtain from mammalian hair cells and unethical to obtain from human patients. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended upon your ability to weigh or judge the validity of certain arguments for using yeast as a model organism for a human deafness gene. If you answered incorrectly, which answer did you choose? Did you think that it is more difficult to study transcription in human cells than yeast cells? Did you think that because the gene was involved with deafness that the answer had to be related to sound transmission? 70) E
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Clarify Question What is the key concept addressed by the question? • What senses are activated by otoliths in fishes? What type of thinking is required? o This is an analyze question because you have to break down the components of a fish ear and understand what role otoliths play in fishes and how changes in otoliths might change their sensory capabilities. Gather Content What do you already know about otoliths? What other information is related to the question? • You already know that otoliths are found in the ears of fishes. You know that they are made out of calcium carbonate, which dissolves under acidic conditions. Otoliths sit on top of sensory hair cells to provide mass to deflect the stereocilia of the hair cells to convert mechanical motion into a neural signal. If the otoliths were to dissolve due to acidity, then the fish would not be able to use the senses of hearing and balance. Thankfully, global warming does not appear to produce this effect in fishes. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Otoliths are found in the inner ear of fishes and are involved in hearing and balance. The other answers refer to senses that do not utilize calcium carbonate otoliths or hair cells (pain, vision, taste, olfaction). Reflect on Process
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended upon your knowledge of the localization of calcium carbonate in fish otoliths and understanding the function of otoliths in the fish inner ear. If you answered incorrectly, which answer did you choose? Did you think that otoliths were important to other sensory systems? 71) B 72) B
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Clarify Question What is the key concept addressed by the question? • What are the results of semicircular canal defects? What type of thinking is required? o This is an evaluate question because you have to weigh and judge the different symptoms and behaviors to match expected outcomes of malformed semicircular canals. Gather Content What do you already know about semicircular canals? What other information is related to the question? • You already know that semicircular canals are part of the inner ear, linked to the cochlea. While the cochlea allows us to hear, the semicircular canals provide us with a sense of balance. The three fluidfilled tubes that make up the semicircular canals are orthogonal to one another. That is, they are oriented at 90 degrees from each other so that motion in any orientation can be detected. If this system did not work, you would not be able to maintain your balance and would fall over easily. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Malformed semicircular canals would lead to problems maintaining balance. Thus a behavior you might see in mice with this defect is that they would fall often. The other behavioral problems are not related to semicircular canals. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended upon your ability to weigh or judge the validity of certain symptoms of malformed semicircular canals. If you answered incorrectly, which answer did you choose? Did you forget that semicircular canals are involved in maintaining balance? 73) C 74) C
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Clarify Question What is the key concept addressed by the question? • What are two effects of glutamate receptor agonists? What type of thinking is required? o This is an evaluate question because you have to weigh and judge the different potential benefits of BMAA despite the fact that it is associated with neurological damage. Gather Content What do you already know about glutamate? What other information is related to the question? • You already know that that glutamate is an important excitatory neurotransmitter. Too much glutamate can lead to excitotoxicity and neuron death, which is why people that eat animals with too much BMAA can have neurological problems. You also know that glutamate is derived from the amino acid glutamic acid and that amino acids are what make up proteins. This is why glutamic acid is often used as a food additive and flavor enhancer in the form of its salt, monosodium glutamate. Since BMAA can bind to glutamate receptors, it can bind to umami taste receptors that bind amino acids like glutamate, and thus provide a savory flavor. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since BMAA is a glutamate receptor agonist, potentially positive side effects could be imparting a strong umami flavor that makes food more delicious. It would not promote the incorporation of Glu into proteins since the agonist has nothing to do with the translation of proteins. Just Version 1
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because it is derived from cyanobacteria, does not ensure that it has unique nutrients. Alanine is a nonessential amino acid, meaning that it can be manufactured by the human body and is not rare. Thus it would not need to come from a diet of cyanobacteria, fruit bats, shark fins, or any other diet. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended upon your ability to weigh or judge the validity of certain potential benefits of BMAA. If you answered incorrectly, which answer did you choose? Did you think that cyanobacteria might have some potential health benefits? Did you know that alanine is a nonessential amino acid? 75) C
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Clarify Question What is the key concept addressed by the question? • What sensory modality responds to the most molecules? What type of thinking is required? o This is an analyze question because you have to break down the process of sensory processing for the main sensory systems and understand the types of receptors and stimuli for each. Gather Content What do you already know about sensory modalities? What other information is related to the question? • You already know that each sensory modality has specific receptors that are activated by specific stimuli. Vision uses photoreceptors that are activated by photons of light. Touch uses mechanoreceptors that are activated by pressure. TRP channels are activated by temperature changes or by a few specific molecules (like capsaicin or menthol). Taste and smell use receptors that bind to chemicals in fluid (taste) or from the air (smell). Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since the question is asking which sensory modality responds to the broadest range of molecules, you can eliminate the possible modalities that do not use molecules, which is vision which uses light and touch which uses pressure. TRP channels can be activated by a few molecules, like capsaicin or menthol, but is generally activated by temperature change. That leaves taste and smell. Of the two there are much more types of smell receptors than taste receptors, which means that smell can Version 1
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respond to the broadest range of molecules. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended upon your knowledge of the sensory modalities and how each modality is stimulated. If you answered incorrectly, what went wrong? Did you think that there are more types of taste receptors than smell receptors? Did you realize that vision and touch and usually TRP channels are not activated by molecules? 76) C
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Clarify Question What is the key concept addressed by the question? • Why are sensory receptors sometimes internal? What type of thinking is required? o This is an evaluate question because you have to weigh and judge the different reasons that taste receptors could be found internally in the body. Gather Content What do you already know about taste receptors? What other information is related to the question? • You already know that that taste receptors are specific to different types of chemical that elicit different flavors (sweet, salty, umami, bitter). You know that sweet receptors like T1R2 are activated by sugars such as sucrose and fructose and artificial sweeteners like saccharin. We know that the pancreas cannot taste in the same sense that our tongue can, so why would it have taste receptors? The pancreas is an organ in the digestive system that produces important hormones such insulin and glucagon which are vital for controlling blood sugar. Since sugars bind to T1R2 receptors, these receptors could be involved in monitoring and regulating blood sugar, which is vitally important as individuals with diabetes can attest. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The pancreas is both an endocrine organ, producing hormones, and a digestive organ, producing enzymes that help to digest food. Thus referring to it as a waste-disposal organ is not very accurate. It is true Version 1
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that protein expression is not always perfect, but cells will avoid wasting energy producing receptors that they do not need. Thus it is unlikely that cells will produce unneeded receptors without any negative consequences. Techniques used to visualize protein expression may lead to background fluorescence or staining, but that is why controls are necessary to avoid false positives. The most logical answer is that chemoreceptors like T1R2 in the pancreas bind to molecules to help monitor blood sugar levels. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended upon your ability to weigh or judge the potential reasons that T1R2 receptors are expressed in the pancreas. If you answered incorrectly, which answer did you choose? Did you think that damaged receptors would be recycled by the pancreas? Did you forget that T1R2 receptors are taste receptors that detect sugars? 77) A
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Clarify Question What is the key concept addressed by the question? • How did eyes evolve? What type of thinking is required? o This is an evaluate question because you have to weigh and judge the different means by which eyes could have evolved. Gather Content What do you already know about eyes? What other information is related to the question? • You already know that the structure of animal eyes differ by group. For example, insects have eyes with multiple lenses while vertebrates only have one. You also know that all eyes have to be able to detect light by means of photoreceptors, and that even the simplest eyes, like the eyespots of some invertebrates like flatworms, contain photoreceptor cells. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The statement that the development of light-sensing organs evolved once, but several eye structures evolved separately makes the most sense in terms of evolution and what you know about the features of eyes in different animal taxa. The statement that eyes were only slightly modified in different taxa is false since eyes can be very different in flatworms, flies, and vertebrates. The statement that modern animal eyes evolved from an ancestor that had no ability to detect light is not true as even simple organisms like flatworms can detect light, although some organisms have secondarily lost the ability to see (such as cavefishes). Version 1
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended upon your ability to weigh or judge the proper process of evolution of the eye. If you chose an incorrect answer, where did you go wrong? Did you think that lightdetection organs can develop with very little developmental constraints? Some genes that control eye development are similar across taxa (like Pax6), showing that development is constrained by similar processes across taxa. Also there are physical constraints on how an eye can develop in order to produce a focused image upon a set of photoreceptor cells. Did you think that eyes only evolved once? It is true that it is thought that light-detection evolved once, but that different types of eyes evolved separately. 78) A
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Clarify Question What is the key concept addressed by the question? • What is the effect of a detached retina? What type of thinking is required? o This is an analyze question because you have to break down the role of the retina into its functions in terms of detecting and focusing an image for vision. Gather Content What do you already know about the retina? What other information is related to the question? • You already know that the retina is located on the back of the eye Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The statement that the retina secretes tears is incorrect as this is done by tear glands outside of the eyeball. The sphincter muscle that controls light transmission is the pupillary constrictor muscle that opens and closes the iris, not the retina. Although light is focused upon the back of the retina in the fovea, what does the focusing is the lens. The retina does have photoreceptor cells that respond to light, so if the retina was detached, the photoreceptor cells would be pulled away from the back of the eye that provides them with access to blood vessels that supply oxygen and nourishment. Without that connection, the photoreceptors would die, resulting in blindness. Reflect on Process
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended not only on distinguishing between answers that described different parts of the eye and choosing the one that was appropriate for describing the retina. If you selected a wrong answer, which one? Since the retina is where the light is focused on the back of the eye, did you think that it is crucial for focusing an image? It is crucial for detecting the image, but the light is focused by the lens before it reaches the retina. 79) B 80) B
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Clarify Question What is the key concept addressed by the question? • Why are carrots good for you? What type of thinking is required? o This is an analyze question because you have to make a link between something in carrots to an effect on health. Gather Content What do you already know about carrots? What other information is related to the question? • You already know that carrots are orange and full of vitamins. What makes a carrot orange? It is called beta-carotene, an orange pigment. You may have heard that carrots are good for you vision, but why? Betacarotene is a precursor to Vitamin A and retinal, which is important in the production of photopigments that are needed for vision. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The statement that beta-carotene is necessary to form lens proteins is incorrect. Also, carrots do not have large amounts of glutamate (which would be found in foods with protein). Since beta-carotene is a precursor to Vitamin A and retinal, which are cofactors in photopigments, eating carrots rich in this compound can be good for your eyes and vision. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? o Answering this question correctly depended not only on distinguishing between compounds that could be found in carrots, but also understanding the functional role of the proper compound (betacarotene) and how this might benefit vision. If you selected a wrong answer, which one? Did you think that since the lens is a vital part of the eye, and you knew that carrots help vision, that it was the correct answer? Did you think this was just an old wive’s tale your mother told you so you would eat your vegetables? 81) D
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Clarify Question What is the key concept addressed by the question? • Why are faint objects hard to see directly? What type of thinking is required? o This is an analyze question because you have to make a link between the characteristics of the retina and the function of looking directly or indirectly at an object. Gather Content What do you already know about vision? What other information is related to the question? • You already know that the retina of the eye is composed of photoreceptors. These photoreceptors come in two types- rods and cones. Rods are for black and white vision and are very sensitive in low light situations while cones are used for color vision and for high acuity in bright light situations. Cones are also concentration at the center of the retina, especially the fovea where focusing occurs, while rods are more prevalent in the peripheral regions of the retina. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The statement that cone photoreceptors are most sensitive at night, and few cones are present in the fovea is opposite of the truth since this statement is defining rods, not cones. Also, rhodopsin and cis-retinal are not transported or build up in the fovea at night. Thus the correct answer is that rod photoreceptors are most sensitive in dim light, and few rods are present in the fovea.
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended not only on distinguishing between rods and cones, but understanding their distribution and function in the retina. If you got the answer wrong, did you get the characteristics of rods and cones reversed? Did you think that rhodopsin, which detects low level light, was transported from one part of the retina to another with a shift in light levels? That does not occur, but rhodopsin is found in rods, which are in the peripheral part of the retina. Thus a faint object can be seen best when not looking directly at it, which focuses on the fovea, and instead looking at it with your peripheral vision, which stimulates the rods of the retina. 82) B
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Clarify Question What is the key concept addressed by the question? • What is the function of jelly in the ampullae of Lorenzini? What type of thinking is required? o This is an analyze question because you have to make a link between the characteristics of the ampullae of Lorenzini and the function of detecting electromagnetic currents. Gather Content What do you already know about electroreception? What other information is related to the question? • You already know that some animals, like sharks, can detect electrical fields like those produced by muscle contraction in prey fish. You also may know that sharks have specialized electroreceptors called ampullae of Lorenzini that are located in sacs that open through jelly- filled canals to pores on the body surface. The jelly is highly conductive, so is an excellent material for the transmission of electrical signals. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The jelly in the ampullae of Lorenzini does not secrete pheromones (smell), contain gustatory (taste) receptors, or act as an electrical insulator. Instead it acts as a good electrical conductor which aids in the detection of electromagnetic currents. Reflect on Process Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended not only on knowing that the ampullae of Lorenzini detects electromagnetic currents and not chemical molecules for taste or smell, but also understanding that their jelly-filled pores have the property of being highly conductive. If you selected an incorrect answer, did you think that the jelly might be a good insulator that would help trap the electrical signal in the pore? Did you get confused with the definitions of “pheromones”and “gustatory”? 83) D
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Clarify Question What is the key concept addressed by the question? • What is the effect of the delay of a neuron to return to a resting state following an action potential? What type of thinking is required? o This is an analyze question because you have to think about the whole process of an action potential to understand how slowing down part of that process can affect subsequent action potentials. Gather Content What do you already know about action potentials? What other information is related to the question? • You already know that action potentials are produced by the opening and closing of sodium and potassium channels. When a stimulus is applied, if it is strong enough to bring the neuron membrane potential above threshold, sodium channels are opened and the cell is depolarized. Shortly thereafter, the sodium channels close and potassium channels open, repolarizing the cell back toward the resting membrane potential. The time it takes to repolarize the cell is called the refractory period. If a mutation causes the sodium channels to stay open longer, then it will take much longer for the cell to be repolarized. A neuron needs to be repolarized before a subsequent action potential can fire. Thus, the longer the refractory period, the longer the time possible between action potentials, and thus a decrease in action potential frequency. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The mutation slowing voltage-gated sodium channels would produce a Version 1
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longer refractory period, thus preventing high frequency action potentials. As high frequency of action potentials represents stronger stimuli, the nervous system would not be able to transmit information about such stimuli. Although receptor potentials may not be affected as significantly as action potentials, receptor potentials lead to action potentials once they reach threshold. This, of course, would affect sensory perception. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended not only on knowing the steps of an action potential including the refractory period, and knowing the difference between a receptor and action potential. If you got it wrong, which answer did you choose? Did you think that this mutation might affect both receptor and action potentials? Did you get the link between refractory period and frequency of action potentials (that is, the shorter the refractory period, the higher the potential frequency)? 84) D 85) Section Break 85.1) A 85.2) D 86) Section Break 86.1) B 86.2) A 86.3) A 86.4) C 87) Section Break 87.1) A Version 1
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87.2) C
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Clarify Question What is the key concept addressed by the question? • What would a transgenic receptor in antennae provide? What type of thinking is required? o This is an analyze question because you have to break sensory (olfaction) signaling into different stages and understand the effect of a novel transgenic receptor on olfaction sensation in honeybees. Gather Content What do you already know about olfaction? What other information is related to the question? • You already know that olfaction detects odorants when odorants bind to specific olfactory receptors and opening up ion channels, producing receptor potentials. What would happen if you express a novel olfactory receptor for TDT on honeybee antennae? The honeybee would be able to sense or smell the TDT. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since the TDT receptor that you have genetically engineered in the honeybee antennae is an olfactory receptor, and olfaction is the sense of smell, then the honeybee will have the ability to smell the TDT, not taste or see TNT. These receptors would bind to TDT, not collect TDT. Reflect on Process Did your problem-solving process lead you to the correct Version 1
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answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended not only on understanding the steps of the sensory pathway of olfaction, but on your ability to understand how a change in this system by genetic engineering can change the perception of the honeybee. If you got an incorrect answer, did you get confused with the definition of olfaction thinking that it was referring to taste, which also uses a similar receptor system? Did you think that TDT does not have a smell? Although we might not be able to detect TDT readily, many animals can. Dogs, for example, can be trained to detect things like explosives via smell. 87.3) A
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Clarify Question What is the key concept addressed by the question? • What type of receptor would a TNT receptor be? What type of thinking is required? o This is an analyze question because you have to break sensory (olfaction) signaling into different stages and understand what activates the receptors involved. Gather Content What do you already know about olfaction? What other information is related to the question? • You already know that olfaction detects odorants when odorants bind to specific olfactory receptors and opening up ion channels, producing receptor potentials. What would happen if you express a novel olfactory receptor for TDT on honeybee antennae? The honeybee would be able to sense or smell the TDT since TDT, which is a chemical, binds to the receptor on an olfactory neuron. Thus the receptor would be a chemoreceptor. Mechanoreceptors are activated in response to mechanical stresses and electromagnetic receptors detect electric currents. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since the TDT receptor that you have genetically engineered in the honeybee antennae is an olfactory receptor, and TDT is a chemical that binds to and activates the receptor, it is a chemoreceptor. Mechanoreceptors are activated in response to mechanical stress and electromagnetic receptors respond to electric Version 1
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currents. While this receptor would be a novel receptor for the honeybee, it is not a novel type of receptor since chemoreceptors are common in the olfactory and gustatory sensory systems. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended not only on understanding the steps of the sensory pathway of olfaction, but on your ability to understand how the change in this system by genetic engineering can provide an additional olfactory receptor for the honeybee and distinguishing what type of receptor this is. If you got an incorrect answer, did you get confused with the definition of chemoreceptor? Did you realize TNT is a chemical? Did you think that because TDT does not normally have an olfactory receptor in honeybees that its receptor would have to be an entirely novel type? 87.4) D
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Clarify Question What is the key concept addressed by the question? • How would the transgenic bees respond to TDT? What type of thinking is required? o This is an analyze question because you have to break sensory (olfaction) signaling into different stages and understand what activates the receptors involved and how this effects behavior. Gather Content What do you already know about olfaction? What other information is related to the question? • You already know that olfaction detects odorants when odorants bind to specific olfactory receptors and opening up ion channels, producing receptor potentials. What would happen if you express a novel olfactory receptor for TDT on honeybee antennae? The honeybee would be able to sense or smell the TDT since TDT, which is a chemical, binds to the receptor on an olfactory neuron. How the bee responds to this stimulus would depend upon which olfactory neuron the receptors are on. If the receptor is co-expressed with other receptors that bind to floral chemicals signaling flowers and a source of pollen, then TDT would attract the bees. If the TDT receptor is co-expressed with other receptors that bind to putrid chemicals or chemicals signaling enemies, then TDT would repel the bees. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since the TDT receptor that you have genetically engineered in Version 1
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the honeybee antennae is an olfactory receptor, and TDT is a chemical that binds to and activates the receptor, it will depend upon which type of olfactory neuron the receptors are expressed. If they are expressed on olfactory neurons that usually attract bees when activated, then TDT would attract them. If they are expressed on olfactory neurons that usually repel bees when activated, then TDT would also repel them. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended not only on understanding the steps of the sensory pathway of olfaction, but on your ability to understand how the change in this system by genetic engineering can provide an additional olfactory receptor for the honeybee and determining the behavior effect of activating these receptors. If you got an incorrect answer, did you realize that these novel receptors would be expressed on olfactory neurons that expressed receptors for other odors? Did you think that because TDT does not normally have an olfactory receptor in honeybees that binding this receptor would elicit no behaviors? 87.5) C
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Clarify Question What is the key concept addressed by the question? • How could transgenic bees help find TDT? What type of thinking is required? o This is an analyze question because you have to break sensory (olfaction) signaling into different stages and understand what activates the receptors involved and how this effects honeybee behavior in order to apply this knowledge to solving a practical problem of TDT detection. Gather Content What do you already know about olfaction? What other information is related to the question? • You already know that olfaction detects odorants when odorants bind to specific olfactory receptors and opening up ion channels, producing receptor potentials. What would happen if you express a novel olfactory receptor for TDT on honeybee antennae? The honeybee would be able to sense or smell the TDT since TDT, which is a chemical, binds to the receptor on an olfactory neuron. How the bee responds to this stimulus would depend upon which olfactory neuron the receptors are on. If the receptor is co-expressed with other receptors that bind to floral chemicals signaling flowers and a source of pollen, then TDT would attract the bees. Even if the receptor was expressed on olfactory neurons that did not signal pollen, if the two odorants are presented simultaneously (both TDT and floral chemicals), the bee will become conditioned to expect a food reward whenever it smells TDT. Such conditioned bees would be attracted the smell of TDT and could potentially help people detect explosives. Version 1
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Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since the TDT receptor that you have genetically engineered in the honeybee antennae is an olfactory receptor, and TDT is a chemical that binds to and activates the receptor, honeybees could be attracted to TDT if they were conditioned to expect a food reward in conjunction with a TDT signal. In fact, the military is currently trying to do just this. The other answers do not seem like very reasonable means of detecting explosives. One answer suggests to watch the death of the bee when the neuron absorbs TNT. First of all, a dead bee cannot provide you with direction- all you would know if that TNT is somewhere nearby. Secondly, although TNT is toxic to animals, it is probably toxic at concentrations that are much higher than detection levels, and it is unlikely that TNT, once bound to the receptor, would then be absorbed into the olfactory neuron. Answer B suggests using an MRI to monitor brain activity of a bee. Although microMRImachines exist, it is highly unlikely that the activity of a few olfactory neurons would be detectable using the resolution available for functional MRI. Also, this technology would be highly expensive and immobile. One answer suggests using a TNT ELISA assay, which seems like a good idea but it is unclear that TDT stays bound to its receptor permanently or whether it only stays for a short moment. In either case, the amount of TDT on the antennae would be miniscule and probably be undetectable by ELISA, which is usually used to detect proteins. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended not only on understanding the steps of the sensory pathway of olfaction, but on your ability to discriminate among different potential means of detecting TDT using honeybees. If you got an incorrect answer, were you unaware of some of the limitations to the techniques proposed in the answers? Did you think that because TDT does not normally have an olfactory receptor in honeybees that binding this receptor would elicit no behaviors, and that bees would be untrainable? 88) Section Break 88.1) B
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Clarify Question What is the key concept addressed by the question? • Why is chili perceived as hot and mint as cold? What type of thinking is required? o This is an analyze question because you have to break down the process of thermoreception and then explain why some chemical compounds elicit a sensation of temperature (either hot or cold). Gather Content What do you already know about TRP channels? What other information is related to the question? • You already know that TRP channels are found in nociceptors that respond to temperature changes. You also may recall that the first TRP receptor discovered responds to the chemical capsaicin, which is found in chili peppers, as well as to heat. Thus, when you eat spicy foods with capsaicin it provides a sensation of heat and pain. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since TRP channels are activated by temperature changes, but capsaicin and menthol act as agonists of TRP channels, these molecules are perceived as hot and cold, respectively. Infrared energy or cultural conventions are not involved in the process. Reflect on Process Did your problem-solving process lead you to the correct Version 1
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answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended not only on understanding that TRP channels monitor temperature changes, but also on your knowledge that TRP channels can be activated by compounds such as capsaicin and menthol. If you got an incorrect answer, did you think that the TRP channels responsive to different compounds go to different regions of the brain? Did you think that cultural conventions of what we consider hot and cold were involved? 88.2) C
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Clarify Question What is the key concept addressed by the question? • Why do plants have TRP agonists? What type of thinking is required? o This is an evaluate question because you have to use logic to evaluate potential reasons that TRP channels exist in plants, without the answer being provided directly in the text. Gather Content What do you already know about TRP channels? What other information is related to the question? • You already know that TRP channels are found in nociceptors that respond to temperature changes. You also may recall that the first TRP receptor discovered responds to the chemical capsaicin, which is found in chili peppers, as well as to heat. Thus, when you eat spicy foods with capsaicin it provides a sensation of heat and pain. Plants have evolved to contain TRP agonists like capsaicin for the same reason some plants have evolved toxic and bitter compounds- to keep animals from eating them. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • TRP channel agonists would not speed up or slow down chemical reactions in the plant, especially since the plants do not have receptors for the agonists (but animals do). For the same reason, they would not warm or cool the plant, but give a warm or cool sensation to animals who consume it. These sensations can be intense and painful, causing the animal (either herbivorous insects Version 1
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or mammals)to spit the plant out and avoid it in the future. While compounds like capsaicin found in hot peppers have been artificially selected to produce larger amounts of the compound for human consumption, plants like peppers did not evolve this compound for human purposes, but for its own survival. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended on your ability to weigh and judge, or evaluate, which the potential effects of TRP channel agonist on plants. If you got an incorrect answer, did you remember that TRP channel agonists like capsaicin bind to TRP channels to provide a sensation of a temperature change, even though the body’s temperature does not really change? Did you have trouble weighing the options that these compounds were evolutionary derived for plant survival relative to artificially selected by man for human cultivation/consumption to determine the correct answer? 88.3) B
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Clarify Question What is the key concept addressed by the question? • What experiment can test why plants have TRP agonists? What type of thinking is required? o This is an evaluate question because you have to use logic to evaluate potential reasons that TRP channels exist in plants, and then determine what one would measure to test that hypothesis. Gather Content What do you already know about TRP channels? What other information is related to the question? • You already know that TRP channels are found in nociceptors that respond to temperature changes. You also may recall that the first TRP receptor discovered responds to the chemical capsaicin, which is found in chili peppers, as well as to heat. Thus, when you eat spicy foods with capsaicin it provides a sensation of heat and pain. Plants have evolved to contain TRP agonists like capsaicin for the same reason some plants have evolved toxic and bitter compounds- to keep animals from eating them. In order to test if animals eat plants with either capsaicin or menthol added to them, one would need to measure leaf or fruit damage that would be caused by browsing. We humans are a strange bunch in which some of us like the sensation of heat caused by capsaicin and cool caused by menthol. Since the plants evolved long before humans did, it is sensible to test for damage caused by animals over palatability to humans. Choose Answer Given what you now know, what information is most likely to Version 1
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produce the correct answer? • TRP channel agonists would not change photosynthetic rate of the plant, especially since the plants do not have receptors for the agonists (but animals do). Similarly, despite what a few health reports state, agonists like capsaicin does not have much of an overall effect of metabolic rate in humans- and besides, this experiment only mentions plants, not humans, so palatability to humans would also not be the best answer. But measuring the amount of leaf and fruit damage to the plants would test if capsaicin or menthol makes plants less palatable to non-human animals. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended on your ability to weigh and judge, or evaluate, which the potential experiments to test the effects of TRP channel agonists on plants. If you got an incorrect answer, did you remember that TRP channel agonists like capsaicin bind to TRP channels to provide a sensation of a temperature change, which can be a painful and unpleasant experience that might prevent animals from eating it? Did you have trouble weighing the options that these compounds were evolutionary derived for plant survival relative to artificially selected by man for human cultivation/consumption to determine the correct answer? Did you realize that the experiment was only dealing with plants, and not humans? 89) Section Break 89.1) B Version 1
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89.2) D 90) Section Break 90.1) D
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Clarify Question What is the key concept addressed by the question? • Would actin or microtubule defects affect hair cells? What type of thinking is required? o This is an analyze question because you have to break down the components of a sensory hair cell and what proteins are involved in order to determine how defects in these proteins would effect hearing. Gather Content What do you already know about hair cells? What other information is related to the question? • You already know that hair cells are found in the organ of Corti in the inner ear. These hair cells have one long kinocilium that is a true cilium that contains microtubules and many smaller stereocilia which are microvilli containing actin fibers. If there is a defect in either microtubules or actin, this may hinder hair cell and thus hearing function. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • As hair cells contain both microtubules (in kinocilia) and actin (in stereocilia), and since both are important in the development and function of hair cells, then a defect in either or both of these types of proteins would likely create problems for hair cell function. Reflect on Process
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended upon your knowledge of the localization of actin and microtubules in sensory hair cells and understanding the function of the stereocilia and kinocilium. If you answered incorrectly, which answer did you choose? Did you think that since there is only one kinocilium per hair cell that the hair cell might still function properly without it? 90.2) C
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Clarify Question What is the key concept addressed by the question? • What sense would actin or microtubule defects affect? What type of thinking is required? o This is an analyze question because you have to break down the components of a sensory hair cell and what proteins are involved in order to determine how defects in these proteins would affect hearing and other senses. Gather Content What do you already know about hair cells? What other information is related to the question? • You already know that hair cells are found in the organ of Corti in the inner ear. These hair cells have one long kinocilium that is a true cilium that contains microtubules and many smaller stereocilia which are microvilli containing actin fibers. If there is a defect in either microtubules or actin, this may hinder hair cell and thus hearing function. Hair cells are also associated with the semicircular canals of the ear which are used for sensing the orientation of the body and balance. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The patient is at an audiology clinic, which usually works with patients with hearing problems. You know that hair cells in the ear have actin and microtubules that are necessary for their proper function for hearing, but hearing is not one of the answers to choose from. So what other sense requires hair cells? Smell, taste, touch, Version 1
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and proprioception do not. That leaves balance. The sense of balance is provided by hair cells that are located at each of three semicircular canals. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended upon your knowledge of the localization of actin and microtubules in sensory hair cells and understanding the function of the stereocilia and kinocilium. If you answered incorrectly, which answer did you choose? Did you think that actin and microtubules are important to other sensory systems besides hearing and balance? Actin and microtubules are important parts of the cytoskeleton of all cells, so that is a good thought, but the key is that the patient is at an audiology clinic which studies diseases of the ear. Balance is provided by semicircular canals and hair cells in the ear, so it is the only logical choice. 91) Section Break 91.1) C
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Clarify Question What is the key concept addressed by the question? • What is the effect of high-sensitivity bitter receptors? What type of thinking is required? o This is an analyze question because you have to break down the components of taste receptors and understand how changes in receptor sensitivity would change the perception of tastants and result in behavior shifts. Gather Content What do you already know about taste receptors? What other information is related to the question? • You already know that in order to detect a taste, tastants must first bind to specific receptors on the tongue and inside the mouth. Bitter tastants detect a variety of molecules and is thought to have evolved as a warning system for toxic compounds. If a receptor has highsensitivity for bitter tastants, then bitter foods will be perceived to be extra bitter and unpalatable and people will avoid those foods. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Individuals with the high-sensitivity variant of hTAS2R38 will be extra sensitive to bitter-tasting foods such as turnips and broccoli and will dislike them and avoid them. They will have to eat less of turnips and broccoli to get the same bitter taste, not more of them. Taste receptors have nothing to do with digestibility or allergies of foods.
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended upon your knowledge of the role of taste receptors and how changing their sensitivity would change how tastes are perceived. If you answered incorrectly, what went wrong? Did you think that high sensitivity receptors would cause individuals to eat more of bitter foods than less? 91.2) D
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Clarify Question What is the key concept addressed by the question? • Why are there variants in human bitter receptors? What type of thinking is required? o This is an evaluate question because you have to weigh and judge the different reasons that variability in a human bitter taste receptor exist. Gather Content What do you already know about taste receptors? What other information is related to the question? • You already know that taste receptors are specific to different types of chemical that elicit different flavors (sweet, salty, umami, bitter). You know that it is hypothesized that bitter receptors evolved to detect compounds that are toxic. Glucosinolates are found in plants like turnips and broccoli which activate hTAS2R38 receptors. Although eating such vegetables has nutritional benefits, the glucosinolates contained in them can also block synthesis and transport of iodine. If an individual’s diet is low in iodine, this could become a problem as blocking what little iodine the individual produces can lead to diseases such as goiter. If an individual’s diet is high in iodine, then glucosinolates may not cause a problem. Thus natural selection on receptors for glucosinolates would vary by geographical region and food supply. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The case study presented here does not present any evidence that Version 1
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iodine produces mutations in genes. As glucosinolates block the synthesis and transport of iodine, it could not help people metabolize iodine no matter what the iodine levels were in their food. It is true that areas of high iodine are coastal, whereas mountainous regions have had much of the iodine washed from the soil, but turnips and broccoli can grow well in coastal areas. Thus the answer is that in areas were iodine levels are low, it was important to avoid foods with glucosinolates so as to not block what little iodine was available to the body, whereas in areas of high iodine, eating a wider range of plants in the diet could be beneficial by providing additional fiber and nutrients. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended upon your ability to weigh or judge the potential benefits and costs of having a diet high in glucosinolates. If you answered incorrectly, which answer did you choose? Did you misunderstand that glucosinates could help people metabolize iodine instead of blocking its synthesis and transport? Did you think that plants high in glucosinolates, like turnips and broccoli, could not be grown in coastal areas? 92) Section Break 92.1) D
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Clarify Question What is the key concept addressed by the question? • How did eye development evolve? What type of thinking is required? o This is an analyze question because you have to break down the role of Pax6 in the process of eye development and understand the process of convergent evolution. Gather Content What do you already know about eyes? What other information is related to the question? • You already know that Pax6 is involved in eye development and that it has been referred to as the master regulatory gene for eye development. You also know, from the chapter reading, that eyes have evolved independently in several distinct taxa of animals, with distinct features. For example, flies have eyes with hundreds of different lenses while mollusks and chordates have a single lens. This is an example of convergent evolution in which analogous structures (not homologous ones) have evolved the same function of vision in different taxa. But something you may not know is that Pax6 regulates the development of a number of sensory organs and other neural tissues, not just eyes. Also, Pax6 may be an important regulatory gene, but it works in conjunction with a number of other developmental genes. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The statement that invertebrates normally have only simple Version 1
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eyespots is simply not true for all invertebrates. Mollusks like squid and octopi have well-developed eyes with a single large lens similar to those of vertebrates. Many different transcription factors can aid in the process of eye development, but there is no evidence of eye development being initiated by the misexpression of genes other than Pax6. The statement that all animal eyes have the same anatomy is also not true, as insects, mollusks, and vertebrate eyes are different in morphology. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended not only on distinguishing between true and false statements about the anatomy of eyes from different taxa, but also understanding that Pax6 is the major, although not only, gene involved in eye development. Since Pax6 affects the development of sensory tissues in general, it makes sense that it could affect the development of eyes in different taxa even if these structures are analogous (evolved independently) instead of homologous (from the same ancestor).
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Chapter 44 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) True or False: Hormones must be present at high concentrations to elicit an effect. ⊚ ⊚
2)
true false
True or False: A molecule can act as both a neurotransmitter and a hormone. ⊚ ⊚
true false
3) True or False: The brain controls organ system function only through direct contact with sympathetic or parasympathetic nerves. ⊚ ⊚
4)
true false
True or False: The thyroid requires negative feedback to prevent overgrowth. ⊚ ⊚
true false
5) True or False: If Ca+2 levels in the blood are too low, hormones from the parathyroid gland can induce bones to dissolve and release calcium. ⊚ ⊚
true false
CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 6) Your general practitioner considers your unusual set of symptoms, and says, "You seem to have a problem with maintaining homeostasis in your body." Which type of specialist might the doctor refer you to? (Check two.)
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A) hematologist B) endocrinologist C) neurologist D) osteologist E) opthamologist F) obstetrician-gynecologist
7)
The anterior pituitary gland is controlled by which three types of signals? (Check three.) A) direct axonalconnections from the hypothalamus B) negative feedback from its ownhormones C) negative feedbackfrom hormones secreted by the thyroid, adrenal cortex, and gonads D) positive feedback from its ownhormones E) positive feedback fromhormones secreted by the pancreas, heart, and skin F) releasinghormones secreted by the hypothalamus
8)
Which are endocrine organs? (Check all that apply.) A) adenohypophysis B) adrenal gland C) cochlea D) hypothalamus E) ileum F) lymph node G) neurohypophysis H) ovary I) pancreas J) pineal gland K) salivary gland L) sebaceousgland M) spleen N) testis O) thyroid gland
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9)
What are the three main categories of hormones? (Check three.) A) adrenergic B) amino acidderivative C) anabolic D) catabolic E) cytosolic F) peptide /protein G) steroid
10) You are scheduled to give a seminar to your fellow med school students, and have chosen to speak about the pituitary. What important points will you include? (Check all that apply.) A) The posteriorpituitary is derived from the brain, while the anterior pituitary is not. B) The anterior pituitary is derived from the brain, while the posterior pituitary is not. C) The pituitary is acompound endocrine gland. D) Each half of the pituitary secretes one important hormone. E) Some pituitaryhormones have sex-specific effects. F) If there is toolittle iodine in the diet, the pituitary can grow into a goiter. G) The pituitary is responsible forproducing at least nine major hormones.
11) Which are important components of the communication between the hypothalamus and anterior pituitary? (Check all that apply.) A) ADH andoxytocin B) capillaries C) fibrous pituitary stalk D) GHIH, PIF, andMIH E) hormones F) hypothalamohypophyseal portal system G) transport ofhormones down axons H) TRH, CRH, GnRH,and GHRH
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12) Which are important components of the communication between the hypothalamus and posterior pituitary? (Check all that apply.) A) ADH andoxytocin B) capillaries C) fibrous pituitary stalk D) GHIH, PIF, andMIH E) hormones F) hypothalamohypophyseal portal system G) transport ofhormones down axons H) TRH, CRH, GnRH,and GHRH
13) You have a pediatric patient with signs of excessive growth, or gigantism. Initial tests reveal abnormally high levels of growth hormone. What other hormone disruptions might be the primary cause of his symptoms? (Check all that apply.) A) high GHIH B) low GHIH C) high GHRH D) low GHRH E) high GnRH F) low GnRH
14) Increased use of MRI technology has resulted in a surprising medical dilemma. Scans used for early detection of tumors often reveal benign internal growths that would otherwise have gone undetected, called incidentalomas. This creates the problem of determining whether the growths are harmful without performing needless surgeries. Assume that you have found a pituitary incidentaloma in one of your patients. What blood tests could you perform to determine whether it is causing dysfunction? (Check all that apply.)
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A) adrenococrticotropic hormone (ACTH) B) luteinizinghormone (LH) C) antidiuretichormone (ADH) D) melanocyte-stimulating hormone (MSH) E) calcitonin F) melatonin G) folliclestimulating hormone (FSH) H) oxytocin I) glucagon J) prolactin(PRL) K) growth hormone(GH) L) thyroid-stimulating hormone (TSH) M) insulin N) thyroxine
15) G protein coupled receptors are a large class of receptors that bind hormones as well as other signaling molecules, neurotransmitters, and even odorants. They are a major target of pharmaceutical drugs for various disorders. Typically, the drug acts as an antagonist, blocking the binding site on the GPCR. Why is the receptor a more attractive drug target than the G protein activated downstream? (Check all that apply.) A) It is easier totarget molecules from the outside of the cell membrane, because getting drugsinto the cell can be difficult. B) Interfering withthe G protein would require getting a drug across several membranes into thecell's nucleus. C) The "G-protein" is not really aprotein but just a GTP molecules, which is too small to be a possible drugtarget. D) Since GPCRs areso widespread and perform many roles in the body, targeting G proteins used bymultiple GPCRs would create side-effects beyond the targeted physiologicalfunction. E) Since the GPCRsbind a variety of unique ligands, their structures are varied enough to be ableto create specific targeted drugs for certain pathways.
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16) To exert its effects on gene regulation in a cell, a steroid hormone must interact with a variety of proteins and cell structures along the way. Check the box for each interaction partner. A) carrierprotein B) microtubules C) plasmamembrane D) hormonereceptor E) nuclearmembrane F) GPCR
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 17) A ______ is a regulatory molecule that is secreted into the blood by an endocrine gland. A) metabolite B) hormone C) peptide D) G protein E) neurotransmitter
18) A hormone is a regulatory molecule that is secreted into the blood by an endocrine gland. What is wrong with this definition? A) Endocrine glandsare the target of these molecules, not the source. B) It does not applyto this type of molecule in plants. C) The molecules donot serve a regulatory role. D) The definition iscompletely correct as stated.
19) You are a professor supervising first year medical students. One student is examining the adrenal gland of his cadaver. "Wow!" he exclaims, "This person must have had an endocrine problem. Their adrenal gland lacks any kind of duct connecting it to the bloodstream. The hormones could only have oozed out." How do you respond?
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A) "That makestheir adrenal gland similar to an exocrine organ." B) "Do you seesigns of adrenal insufficiency, such as low fat stores or muscledegeneration?" C) "That'snormal. The hormones ooze out and diffuse into nearby capillaries, which is whyendocrine glands are sometimes called 'ductless glands'." D) "Lookcarefully and you will see the nerves that transport the hormones into thebloodstream."
20) Some intercellular regulatory molecules that exert only very local effects are called ________ regulators. A) sympathetic B) exogeneous C) merocrine D) endocrine E) paracrine
21) The ________ lobe of the pituitary gland appears fibrous because it contains axons originating from hypothalamic neurons. A) anterior B) posterior C) superior D) inferior E) medial
22) There is a molecule in black licorice that inhibits an enzyme which normally limits activation of mineralocorticoid receptors. Thus, overconsumption of licorice can mimic the effect of excess aldosterone. What would be the result?
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A) infertility inmen B) hypertension (highblood pressure) due to insufficient potassium in the blood C) excessive bodyhair D) low blood pressuredue to excessive potassium in the blood
23) A novel disease causes destruction of the adrenal glands. If a patient with this disease failed to receive aldosterone replacement therapy, what would result? A) death B) diminishedcognitive function C) infertility inboth men and women D) poor blood sugarregulation
24)
The islets of Langerhans located in the _______ secrete both insulin and glucagon. A) liver B) pituitary C) thalamus D) kidney E) pancreas
25)
Ecdysone and juvenile hormone regulate molting and ____________ in insects. A) metamorphosis B) sexualbehavior C) body shape D) egg production
26) Women often receive synthetic oxytocin to induce childbirth or augment contractions. What is an important consideration about the use of synthetic oxytocin?
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A) It is impossibleto mimic its chemical structure, so it may act on other receptors and causeside effects. B) The syntheticform does not travel down motor neurons, so it is less effective than thenatural form. C) It can bedifficult to get the levels just right, so uterine contractions can be toostrong. D) If you fail tosimultaneously provide synthetic G protein, the hormone is ineffective.
27) A couple visits a fertility clinic to determine the basis of their difficulty in conceiving a child. They are surprised to hear they will both be tested for levels of two of the same hormones, which play roles in the ovarian cycle and sperm production. Which hormones are they? A) adrenocorticotropic hormone (ACTH) and corticotropin-releasing hormone(CRH) B) insulin andglucagon C) oxytocin andluteinizing hormone (LH) D) follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
28) The use of bovine growth hormone (BGH) to increase milk yield in dairy cows is highly controversial. What other hormone is regularly added to milk, yet causes little controversy? A) vitamin A B) vitamin D C) MSG D) preservatives
29)
What is the primary function of the hormone ADH? A) regulates biological rhythms B) mediatesadaptation to long term stress C) stimulates bonebreakdown D) conserves water by stimulating its reabsorption from urine E) inhibits loss of calcium from bone
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30)
What is a primary function of growth hormone? A) initiates stress response B) raises blood glucose level C) lowers blood glucose level D) stimulates bone growth E) inhibits loss of calcium from bone
31)
What is a primary function of the hormone calcitonin? A) initiates stress response B) raises blood glucose level C) lowers blood glucose level D) stimulates bone growth E) inhibits loss of calcium from bone
32) Lampreys completely lack parathyroid glands. Suggest why these glands may be important for other vertebrates, but not for jawless fish. A) Because they are parasitic, lampreys get plenty of calcium from their hosts. B) Living in the ocean, they are surrounded by large amounts of sodium, chloride, and magnesium ions. C) Jawless fishemploy a different system than other vertebrates to regulate blood sugar. D) Since they have acartilaginous skeleton but not true bone, they have less need to regulatecalcium levels.
33)
Which hormone helps with adaptation to long term stress?
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A) glucocorticoids B) epinephrine C) insulin D) glucagon E) melatonin
34)
Which hormone lowers blood glucose levels? A) glucocorticoids B) epinephrine C) insulin D) glucagon E) melatonin
35)
Which hormone raises blood glucose levels? A) glucocorticoids B) epinephrine C) insulin D) glucagon E) melatonin
36) At the breakfast table, your roommate says, "Oops! I forgot to take my melatonin last night. I'd better take it now." How do you respond? A) "Good idea --you don't want your bones to get brittle." B) "Be sure notto take too much, or your blood sugar could get dangerously low." C) "Don't takeit now - it regulates biological rhythms, and is normally high at night and lowduring the day." D) "Don't takeit after a meal - it promotes the 'fight-or-flight' response, not'rest-anddigest'."
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37)
Which hormone sets the body's basal metabolic rate? A) estrogen B) insulin C) norepinephrine D) cortisol E) thyroxin
38) The hormones epinephrine and norepinephrine constitute the "alarm" response of the body to stress. What secretes these hormones? A) pancreas B) thyroid gland C) adrenal medulla D) pineal gland E) anterior pituitarygland
39)
What is an example of a molecule that can act as both a neurotransmitter and a hormone? A) estrogen B) progesterone C) thyroxine D) norepinephrine E) insulin
40) Which of the following is a paracrine regulator that affects almost every organ in the body?
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A) insulin B) testosterone C) prostaglandin D) gonadotropin E) epinephrine
41) Which of the following hormones exerts its action by interacting with a receptor at the cell surface? A) insulin B) cortisol C) testosterone D) estrogen E) progesterone
42)
Which hormone is NOT produced by the anterior pituitary gland? A) prolactin B) luteinizinghormone C) calcitonin D) growth hormone
43)
Why does consumption of alcohol stimulate urination? A) It stimulates ADHsecretion. B) It inhibits ADHsecretion. C) It stimulatesvasopressin. D) It stimulatesoxytocin. E) It inhibitsaldosterone.
44)
What hormone stimulates the milk-ejection reflex?
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A) antidiuretichormone B) oxytocin C) vasopressin D) parathyroidhormone E) aldosterone
45) Hormones of the posterior pituitary gland are transported to the hypothalamus by what unusual route? A) the limbicsystem B) blood vessels C) axons D) the lymphaticsystem E) the hypopituitaryshunt
46)
What hormone stimulates milk production in mammals? A) aldosterone B) melatonin C) prolactin D) luteinizinghormone E) growth hormone
47)
Which of the following are examples of gonadotropins? A) prolactin andoxytocin B) follicle-stimulating hormone and oxytocin C) luteinizinghormone and estrogen D) prolactin andestrogen E) follicle-stimulating hormone and luteinizing hormone
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48) Nonpolar hormones can pass through the intestinal cell membrane without being digested, and therefore can be taken orally. Which of the following hormones are available as pills? A) insulin and growth hormone B) thyroid hormone and steroid hormones C) calcitonin andinsulin D) insulin andsteroid hormones E) calcitonin andthyroid hormone
49)
Which is NOT an effect of the hormonal products of the adrenal medulla? A) accelerateheartbeat B) stimulatesynthesis of glycogen C) increase bloodpressure D) reduce blood flowto the skin and digestive organs E) increase bloodsugar
50) Which one of the following is a glucocorticoid important in both gluconeogenesis (glucose produced from amino acids) during starvation and anti-inflammation? A) aldosterone B) cortisol C) glucagon D) insulin E) prolactin
51)
Which of the following hormones is NOT produced by the adrenal gland?
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A) epinephrine B) cortisol C) prolactin D) aldosterone E) norepinephrine
52)
Which two hormones interact to maintain normal levels of blood glucose? A) cortisone andtestosterone B) epinephrine andnorepinephrine C) glucagon andinsulin D) LH and FSH E) oxytocin andvasopressin
53) When the body's blood glucose level rises above normal, which of the following hormones is produced? A) glucagon B) epinephrine C) insulin D) norepinephrine E) prolactin
54)
Which of the following conditions is not associated with diabetes? A) elevated levels of blood glucose B) lowered production of insulin by the pancreas C) reduced body cellsensitivity to insulin D) defects inpituitary gland function E) careful diet andexercise measures are required to balance blood sugar levels
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55) The right atrium secretes atrial natriuretic hormone (ANH), which stimulates the kidneys to excrete salt and water into the urine. ANH acts antagonistically to what other hormone? A) cortisol B) aldosterone C) glucagon D) thyroxine E) progesterone
56)
Which of the following is NOT an example of a sex steroid hormone? A) estrogen B) progesterone C) prolactin D) testosterone E) estradiol
57)
Which of the following hormones regulates metamorphosis and molting in insects? A) melatonin B) ecdysone C) estrogen D) somatostatin E) trypsin
58) Which two systems in the human body are devoted exclusively to the regulation of organ function?
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A) endocrine andcirculatory systems B) respiratory andcirculatory systems C) nervous andcirculatory systems D) nervous andendocrine systems E) respiratory andnervous systems
59)
Choose the hormone that is NOT correctly matched with its chemical category. A) polypeptides—ADH B) steroid—estradiol C) amine—FSH D) glycoprotein—LH E) steroid—testosterone
60)
Which statement below does NOT correctly describe paracrine regulation?
A) Paracrineregulatory molecules include cytokines and growth factors. B) Nitric oxide canfunction either as a neurotransmitter or a paracrine regulatory molecule. C) Endothelin andbradykinin are paracrine molecules that control blood vessel constriction anddilation. D) Paracrine moleculesare released into the circulatory system to affect distant tissues. E) Platelet-derivedgrowth factor and insulin-like growth factor are both paracrine regulatorymolecules.
61) Choose the hormone that is NOT correctly matched with the endocrine gland that secretes it.
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A) adrenal cortex—aldosterone B) pancreas—insulin C) pineal gland—melatonin D) adrenal medulla—cortisol E) posterior lobe of pituitary gland—oxytocin
62) The cells of the anterior lobe of the pituitary gland secrete many hormones. From the following list select the hormone that is NOT secreted from the anterior lobe of the pituitary. A) growth hormone B) prolactin C) follicle-stimulating hormone D) melanocyte-stimulating hormone E) antidiuretic hormone
63) Large or polar hormones cannot enter a cell directly. Which of the following molecules can act as a second messenger for such hormones? A) catecholamine B) cyclic AMP C) epinephrine D) norepinephrine E) calcitonin
64)
Which statement does NOT correctly describe hormones that can directly enter a cell?
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A) Steroid hormonescan enter directly into cells because of their hydrophobic makeup. B) Water-solublehormones can enter directly into cells because of their nonpolar makeup. C) Steroid hormonesdissolve poorly in the plasma and are transported to target cells via specialprotein carriers. D) Once thesehormones enter a cell, they bind to a cytoplasmic receptor and travel as acomplex to the nucleus, or they may bind to the receptor after entering thenucleus.
65)
Which of the following does NOT correctly describe antidiuretic hormone? A) It regulates water turnover in the mammalian kidney. B) ADH secretion isstimulated by high blood osmolarity. C) It ultimately acts to reabsorb more water. D) It exerts iteffects via the cAMP pathway. E) It does notinvolve the use of aquaporin molecules.
66)
Which hormone is secreted by alpha cells of the pancreas in response to hypoglycemia? A) glucagon B) insulin C) glucose D) cortisol E) glycogen
67)
Which hormone is most similar in amino acid structure to chicken vasotocin? A) antidiuretichormone B) aldosterone C) angiotensin II D) growth hormone E) oxytocin
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68)
Which is the best explanation for how ibuprofen works? A) It thins theblood to relieve joint pain. B) It inhibitscyclooxygenase-2, which is needed to produce prostaglandins. C) It activatescyclooxygenase-2, which then produces more prostaglandins. D) It down-regulatesthe production of substance P. E) It activatescyclooxygenase-2, which promotes healing of tissue.
69)
Which of the following is likely to occur after drinking three alcoholic beverages? A) Increasedurination due to alcohol activating antiduretic hormone production. B) Decreasedurination due to alcohol activating aldosterone production. C) Increasedurination due to alcohol inhibiting antidiuretic hormone production. D) Decreasedurination due to alcohol inhibiting antidiuretic hormone production. E) Increasedurination due to alcohol inhibiting aldosterone production.
70)
Which of the following is NOT a function of oxytocin? A) pair bonding B) milk-ejection reflex C) milk production D) uterine contractions
71)
Which of the following hormones has the fewest targets? A) growth hormone B) melatonin C) oxytocin D) thyroid-stimulating hormone E) testosterone
72)
Which of the following is NOT a function of parathyroid hormone?
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A) It increasescalcium production in the liver. B) It increasescalcium absorption across the intestine. C) It increasesreabsorption of Ca2+ in the kidney. D) It stimulatesosteoclasts to dissolve CaPO4 crystals inbone.
73)
Which of the following features distinguishes all hormones from neurotransmitters?
A) Hormones requirelarge concentrations to have an effect, while neurotransmitters require onlylow concentrations. B) A hormone affects reproductive functions, while neurotransmitters control all other processes. C) Hormones travel viathe blood to a target tissue, while neurotransmitters cross the synaptic cleftto a postsynaptic cell. D) Hormones are steroids, while neurotransmitters are amino acids.
74)
What is the difference between the endocrine system and the autonomic nervous system?
A) The endocrinesystem employs chemical signals only, while the autonomic nervous systeminvolves a combination of electrical and chemical signals. B) The autonomicnervous system promotes "fight or flight" functions, while theendocrine system promotes "rest and digest" functions. C) Norepinephrine is produced by the autonomic nervous system, while epinephrine is produced by the endocrine system. D) The axons of neurons of the endocrine system travel a shorter distance than those of the autonomic nervous system.
75) If blood transports hormones throughout the body, how do they communicate with specific targets?
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A) Special gatewayvalves in the blood vessels direct hormones to their target tissues. B) Special carrierproteins "walk" along microtubule tracts to deliver the hormones totheir targets. C) Axonal pathfinding mediates the delivery of hormones to their specific targets. D) Only targettissues have receptors that allow them to receive the signal.
76)
Why don't hormones build up in the body over time? A) They are secretedfrom the body by exocrine glands. B) They are filtered out of the blood by lymph tissues. C) They do, but target tissues become desensitized over time. D) They are degradedby enzymes in the target tissue.
77) You are studying a disease caused by insufficient levels of a specific peptide hormone, and characterize mutations in several genes that can lead to the disease. Your startup company can only afford to pursue one gene product as a possible therapy. Which would you choose? A) Gene A -- atranscription factor. B) Gene B -- anenzyme that activates the hormone by cleaving its inactive precursor. C) Gene C -- thehormone itself. D) Gene D -- a kinasethat acts downstream of the hormone.
78) You are researching an "orphan disease" with no available treatment. Your lab develops a drug that mimics a lipophilic hormone thought to be lacking in the disease, and you are looking for a pharmaceutical company to partner with to run a clinical trial. Based on the reaction from each team, which would you choose to work with?
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A) Company A:"What you've developed is wonderful, but we'll need to develop a deliverysystem to get the drug across the cell membrane." B) Company B:"Your new drug seems very promising. Do you know which G-protein coupledreceptor it binds to?" C) Company C:"We're interested in developing this drug - it could really help people. Doyou know which genes the hormone regulates?"
79) You are an attending physician supervising a new resident. Together, you decide to treat a patient with a steroid drug. The resident administers the drug and watches the patient anxiously. "It's not working," he mutters. How do you respond? A) "You're right,it doesn't seem to be working. Let's increase the dose, since we need toachieve high steroid levels in the blood." B) "Why don't yougo on your rounds and come back? Steroid hormones need several hours to work,since they regulate gene expression. Transcription and translation taketime." C) "We forgot toadminister the carrier protein to get the drug across the cell membrane. We canadd that now." D) "Let's grab acup of coffee and then check again. Activating the G-protein coupled receptorand its downstream kinase cascade can take several minutes."
80) ACTH stands for adrenocorticotropic hormone, but it is produced in the anterior pituitary. What is the basis of this name? A) It is expressedmost highly in tropical climates. B) It stimulates theadrenal cortex. C) It signals to the kidneys to reabsorb water. D) It stimulates appetite by acting on the cerebral cortex.
81)
What stimulates the production of adrenocorticotropic hormone (ACTH)?
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A) GHRH B) CRH C) CIH D) ADH
82) Your doctor returns with your lab results and looks grave. “I’m afraid,” she says, “you seem to have a problem with your hypophysis.” What do you say? A) “Doctor,right now I’m interested in results, not testable ideas about how thingswork!” B) “Well,that’s only responsible for one or two hormones, so it should be easy totreat.” C) “Am I goingto need insulin shots?” D) “Is it theposterior? Neurological problems run in my family.”
83) A middle-aged female patient complains of changes to her face. Her cheekbones and eyebrows have become more prominent, and her jaw is growing. You suspect acromegaly, a disorder caused by excessive growth hormone. She had no growth abnormalities in her youth. What do you suspect is the most likely cause of her problem? A) a tumour of thepineal gland B) congenitalmutation of the GH regulatory region C) a tumour of theanterior pituitary D) a tumour of the posterior pituitary E) menopause
84) Your friend is concerned because although she has never been pregnant, her breasts are producing milk. When she went to the doctor, he sent her to the MRI lab for a brain scan. She was too embarrassed to ask the doctor why. What do you tell her?
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A) "They wereactually scanning your thyroid gland, not your brain. Are you getting enoughiodine in your diet?" B) "The MRItechnician must have mixed up your patient records. He should have done athoracic scan instead." C) "LH and FSHfrom the posterior pituitary stimulate milk production. The doctor wants torule out excess levels of estrogen in the pituitary stalk." D) "Prolactinfrom the anterior pituitary stimulates milk production. The doctor probablywants to rule out a pituitary tumor."
85) Blood glucose levels must be carefully maintained within a narrow window. What endocrine organ is responsible for this task? A) pancreas B) pineal gland C) pituitary gland D) parathyroid gland
86)
What strategy does the body use for blood glucose homeostasis? A) release ofhormones by the brain B) energy stores in bone allow for quick glucose release C) glucose usage bythe brain is shut down when necessary D) the action of twoantagonistic effectors
87)
When a diabetic injects insulin, what does this accomplish? A) promotes glucoserelease from cells, raising blood glucose B) promotes uptakeof glucose into cells, lowering blood glucose C) promotes hydrolysis of glycogen, raising blood glucose D) improves the ability of the body to sense blood glucose levels
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88) Estrogen and testosterone are steroid hormones that differ by only a few atoms. The different receptor binding properties those differences confer allow the hormones to do what during development? A) Causedifferential maturation of the prefrontal cortex during late adolescence. B) Cause a slight increase in muscle mass in females versus males. C) Make females naturally attracted to pink and males to blue. D) Controldevelopment of all sex-specific physical traits including sex organs, bodyhair, and breasts.
89) Atrial natriuretic hormone (ANH) stimulates the kidneys to excrete salt and water in the urine. Why does it make sense that the heart is the source of ANH? A) The heart is amajor endocrine organ that releases several hormones. B) ANH helpsregulate blood pressure, which is sensed by distension of the heart atria. C) The heart is conveniently close to the hypothalamus. D) Secretion of hormones by the heart makes it easy for them to enter the bloodstream.
90) What nonendocrine organ produces erythropoietin, which stimulates red blood cell production in the bone marrow? A) kidneys B) skin C) heart D) pituitary E) liver
91) Beta-blockers are a class of drugs that target beta-adrenergic receptors, blocking the action of epinephrine and norepinephrine. These drugs are used to treat heart conditions, hypertension, glaucoma, and migraine headaches and are also used off-label to alleviate stage fright in performers. Since the beta-adrenergic receptor is a GPCR, what intracellular event is prevented by the use of a beta-blocker?
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A) a protein kinasecascade, initiated by the receptor's intracellular kinase domain B) release of anactivated G protein subunit bound to GTP C) transport of thereceptor-hormone complex into the cell and the nucleus, where it would regulatetranscription D) a proteinphosphatase cascade, initiated by the receptor's intracellularphosphatase domain
92) Ultimately, the signal from a peptide hormone is typically conveyed to the effectors in the cell via the transfer of what molecular moiety? A) nucleotide B) NO (nitricoxide) C) H2O D) phosphategroup E) amino acid
SECTION BREAK. Answer all the part questions. 93) Sometimes the most practical way to do an experiment is not to perform it in an animal, but to look at cell responses in culture. Cells from mice, humans, and other mammals have been used to establish cell culture lines that have been very important for research. You are studying a novel water-soluble mouse hormone. You know cell culture can be a practical model to reveal protein function, so you apply the hormone to yeast cells, but nothing happens.
93.1)
What is a likely explanation for why nothing happened in your experiment?
A) Yeast have a cellwall, so the molecule cannot pass through the cell membrane as it would inmice. B) Water-solublehormones are lipids, not proteins. C) You need to applythe hormone in large amounts to see an effect. D) Yeast may lack thereceptor required for the hormone to act.
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A) Apply the hormoneto mouse cell culture. B) Apply the hormoneat a concentration of 0.5M. C) Hydrolyze thehormone before application. D) Add ATP as acofactor.
94) The basic categories of hormones are peptide or proteins, steroids, and amino acid derivatives. The chemical properties of each hormone type determine some of its functional properties and how it must interact with receptors to signal to the cell.
94.1) A new hormone is discovered. Tests reveal that it is small, hydrophilic, and degraded by a protease. What type of hormone is it? A) peptide B) amino acid derivative C) steroid D) glucocorticoid E) prostaglandin
95) Cushing's syndrome causes weight gain, excessive sweating, and muscle weakness. It can result from either the production of abnormally high levels of cortisol by the body, or overuse of glucocorticosteroid drugs. You are an endocrinologist working with a Cushing's syndrome patient. She is on hormonal birth control pills and takes an occasional ibuprofen.
95.1)
What lab tests would you order to find the source of the problem?
A) cortisol, LH, andFSH B) None -- the birthcontrol pills include corticosteroid hormones. She should switch to anotherform of birth control. C) cortisol, ACTH,and CRH D) cortisol and ACTH
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95.2) Results from lab tests reveal abnormally high endogenous hormone levels, and you suspect a possible tumor. What regions will you ask the MRI technician to focus on? A) hypothalamus,anterior pituitary, and adrenal cortex B) adrenalcortex only C) hypothalamusand posterior pituitary D) anterior andposterior pituitary
96) Many insecticides target insect hormones such as juvenile hormone or ecdysone to disrupt development. This is preferable to simply killing the insect with more broadly-acting toxins.
96.1) Your cat has fleas! You look at the ingredients in the flea control ointment, and see that it contains methoprene, a juvenile hormone analog. What does this accomplish? A) prevents flea larvae from maturing B) kills juvenile fleas C) reinvigorates the cat's immune system, to repel the fleas D) forces juvenile fleas to mature early, disrupting development of reproductive organs
96.2) What is a benefit of targeting hormone signaling rather than a generic cellular housekeeping process in insects? A) It is watersoluble. B) It works very quickly. C) It disrupts the entire population in the area. D) It is specific toinsects and less toxic to mammals.
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Answer Key Test name: Chap 44_13e_Raven 1) FALSE 2) TRUE 3) FALSE 4) TRUE The resulting overgrowth is called a goiter. 5) TRUE 6) [B, C]
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Clarify Question What is the key concept addressed by the question? • How are medical specialists in homeostasis? What type of thinking is required? o This is an evaluate question because you have to discriminate between different types of doctors to see which ones deal with homeostasis. Gather Content What do you already know about homeostasis? What other information is related to the question? • You already know that homeostasis is maintaining relatively stable physiological conditions within the body. The endocrine system helps maintain homeostasis by circulating hormones around the bloodstream. Where are the glands of the endocrine system located? The pineal and pituitary glands are located in the brain. Other glands are located all over the body including the thyroid, thymus, ovaries, testis, and pancreas. What is the name of a doctor who specializes in the endocrine system? What about a doctor who specializes on the nervous system? Choose Answer Given what you now know, what information is most likely to produce the correct answer? • A hematologists studies blood; an osteologist studies bone; an opthamologist studies eyes; an obstetrician-gynecologist studies the female reproductive system; a neurologist studies the nervous system; an endocrinologist studies the endocrine system. These latter two study systems with glands, although if you could make a third choice, you could also select a gynecologist who would deal with the ovary and its Version 1
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hormones. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended not only on knowing what homeostasis is and how it is maintained in the body, but also on evaluating which type of doctor is the most appropriate for helping one maintain homeostasis. Did you select the two correct answers? If so, wonderful. If not, did you chose obstetrician-gynecologist because they know about the ovary and how its hormones affect women’s health? You are right, but the pituitary in the brain and the other glands of the endocrine system like the pancreas and thyroid have a much larger role in the overall homeostasis in the body relative to the gonads. 7) [B, C, F]
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Clarify Question What is the key concept addressed by the question? • What regulates anterior pituitary hormones? What type of thinking is required? o This is an analyze question because you have to understand different mechanisms of hormonal regulation and distinguish between different potential mechanisms for the anterior pituitary. Gather Content What do you already know about the anterior pituitary gland? What other information is related to the question? • The anterior pituitary gland, also known as the adenohypophysis, releases a number of hormones including adrenocorticotropic hormone, melanocyte-stimulating hormone, growth hormone, prolactin, thyroidstimulating hormone, luteinizing hormone, and follicle-simulating hormone. The anterior pituitary gland is controlled by the hypothalamus via production and secretion of releasing or inhibiting hormones. Both the hypothalamus and anterior pituitary gland are controlled via negative feedback by the same hormones that they secrete, as well as hormones from peripheral glands such as the thyroid, adrenal cortex, and gonads. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Applying what you know, you can discount the answer stating that there are direct axonal connections from the hypothalamus. The anterior pituitary, which is derived from a pouch of epithelial tissue that pinches off from the roof of the embryo’s mouth, is not directly connected to the brain like the posterior pituitary gland is. You also know that the anterior Version 1
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pituitary gland is negatively regulated by a number of hormones, so do not select answers referring to positive feedback. Besides negative feedback from its own hormones and peripheral hormones, the anterior pituitary is controlled by releasing and inhibiting hormones secreted by the hypothalamus. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended upon understanding the multiple pathways of regulation for the anterior pituitary gland. If you selected the three correct answers, great! If not, what went wrong? Did you confuse positive and negative feedback? Did you remember that the anterior pituitary is controlled by the hypothalamus and think that the control was via neurons instead of via hormones produced by the hypothalamus? 8) [A, B, D, G, H, I, J, N, O] 9) [B, F, G] 10) [A, C, E, G]
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Clarify Question What is the key concept addressed by the question? • Important points about the pituitary. What type of thinking is required? o This is an analyze question because you have to carefully examine each point to assess its accuracy in terms of describing the pituitary gland. Gather Content What do you already know about the pituitary gland? What other information is related to the question? • The pituitary gland hangs from a stalk from the hypothalamus at the base of the brain. This gland has two parts- the anterior pituitary, or adenohypophyis, and the posterior pituitary gland, or the neurohypophysis. These two portions have different embryonic origins and secrete different hormones. Developmentally, the posterior pituitary is derived from the hypothalamus of the brain, while the anterior pituitary is derived from a pouch of epithelia tissue from the roof of the embryo’s mouth. Hormones released by the posterior pituitary gland include antidiuretic hormone and oxytocin, while the anterior pituitary gland produces adrenocorticotropic hormone, melanocyte-stimulating hormone, growth hormone, prolactin, thyroid-stimulating hormone, luteinizing hormone, and follicle-stimulating hormone. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The individual points are like multiple True/False questions. From the reading you should know that the pituitary is a compound endocrine Version 1
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gland composed of the anterior and posterior pituitary. The posterior portion is derived from the brain and the anterior pituitary is not, so the answer that says the reverse is incorrect. The posterior pituitary produces at least two hormones and the anterior produces at least seven hormones, so the pituitary is responsible for producing at least nine major hormones, not just one for each side. The pituitary does not grow into a goiter, the thyroid gland does, so that answer is incorrect. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Answering this question correctly depended upon assessing each statement as to its accuracy in describing the pituitary gland. If you got the answers correct, great! If not, which answers did you choose? Did you think that because the anterior pituitary produces thyroidstimulating hormone and you knew that goiter and the thyroid were related in some way that goiter occurred in the pituitary instead of the thyroid gland? Did you confuse which part of the pituitary was derived from the brain? 11) [B, D, E, F, H] 12) [A, C, E, G] 13) [B, C]
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Clarify Question What is the key concept addressed by the question? • What is the potential source of excess growth hormone? What type of thinking is required? o This is an evaluate question because you have to consider each hormone and whether higher or lower levels of that hormone would lead to increased growth hormone. Gather Content What do you already know about growth hormone? What other information is related to the question? • Growth hormone (GH) is produced by the anterior pituitary gland and regulates the growth of muscles, bones, and other tissues. The hypothalamus produces two hormones that regulate the production of GH- growth hormone-releasing hormone (GHRH) and growth hormoneinhibiting hormone (GHIH). As the names suggest, GHRH increases GH production and GHIH decreases it. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • GnRH, or gonadotropin-releasing hormone, does not regulate growth hormone, but stimulates the release of FSH and LH, so answers referring to GnRH cannot be correct. GHIH inhibits GH, and our patient has high levels of GH, suggesting that GHIH levels could be very low so that GH production is not inhibited. Alternatively, GHRH, which promotes GH production, could higher than normal. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended upon evaluating each hormone as to its appropriateness in finding the cause of increased growth hormone. If you got the answer correct, great! If not, which answer did you choose? Did you confuse GnRH with GHRH? Did you understand that releasing means increasing and inhibiting means decreasing? 14) [A, B, C, D, G, H, J, K, L]
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Clarify Question What is the key concept addressed by the question? • Tests for pituitary function. What type of thinking is required? o This is an evaluate question because you have to consider each hormone and decide whether it is produced by the pituitary gland. Gather Content What do you already know about the pituitary gland? What other information is related to the question? • The pituitary gland is composed to two components- the anterior and posterior pituitary. The anterior produces ACTH, MSH, GH, PRL, TSH, LH, and FSH, while the posterior produces ASH and oxytocin. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The anterior produces ACTH, MSH, GH, PRL, TSH, LH, and FSH, while the posterior produces ASH and oxytocin. Thyroxine and calcitonin are produced by the thyroid gland. Insulin and glucagon are produced by the pancreas. Melatonin is produced in the pineal gland. Since the incidentaloma was found in the pituitary gland, you would only need to do the tests for hormones produced by the pituitary. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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Answering this question correctly depended upon evaluating each hormone as to whether or not it is produced by the pituitary gland, where the incidentaloma was found. If you got the answer correct, great! If not, which answers did you choose? Did you think that insulin or glucagon was produced in the pituitary? They are produced in the pancreas. Were you thinking of only one portion of the pituitary- either the anterior or posterior? Did you think that thyroxine or calcitonin was produced in the pituitary? They are produced in the thyroid gland. 15) [A, D, E]
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Clarify Question What is the key concept addressed by the question? • Why do drugs target G protein coupled-receptors instead of G proteins? What type of thinking is required? o This is an analyze question because you have to discriminate between different potential advantages of drugs targeting G protein-coupled receptors instead of G proteins. Gather Content What do you already know about G protein-coupled receptors? What other information is related to the question? • G protein-coupled receptors are found in the cell membrane and ligands outside of the cell bind to the receptors to activate G proteins located inside the cell. These G proteins in turn activate secondmessenger producing enzymes to elicit changes within the cell. Such receptors are important for hydrophilic molecules such as protein hormones which cannot cross the phospholipid bilayer of the cell membrane. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Let us examine the answers. One of the answers suggests that the drug would need to get into the cell’s nucleus. While hydrophobic molecules like steroid hormones can diffuse across the cell membrane and into the cell’s nucleus to elicit changes in gene expression, protein hormones cannot do this and so must use receptors located on the outside of the cell. G protein-coupled receptors bind to a variety of unique ligands, so Version 1
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can be involved in a number of different cellular pathways. Thus blocking the binding site will target specific pathways, while blocking G proteins themselves would target many pathways and potentially lead to negative side-effects. G proteins are indeed proteins. They are enzymes that bind to GTP and hydrolyze it to GDP. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended upon analyzing each potential answer for accuracy in terms of describing the role of G protein-coupled receptors. If you got the answers correct, great! If not, which answers did you choose? Did you think that G-proteins cross the nuclear membrane? Because proteins are usually hydrophilic, they do not readily cross membranes. Did you know that G proteins are associated with GTP, so you selected that answer? G proteins do hydrolyze GTP to GDP, acting like an on-off switch, but it is a protein. 16) [A, C, D, E]
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Clarify Question What is the key concept addressed by the question? • What do steroid hormones interact with? What type of thinking is required? o This is an analyze question because you have to understand the complete process of steroid hormone-induced gene regulation and the other key structures in the process. Gather Content What do you already know about steroidhormones? What other information is related to the question? • Steroid hormones, because they are lipophilic, must be carrier through the blood on special carrier proteins. When they arrive at the tissues, they dissociate from their carrier and diffuse across the phospholipid bilayer of cells. Once within the cell, the steroid binds to receptors and form hormone-receptor complexes that then bind to hormone response elements on the DNA after passing into the nucleus through nuclear pores. The hormone-receptor complex regulates the production of messenger RNA for specific proteins. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Carrier proteins are needed to transport steroid hormones because it makes them soluble and prolong their survival in the blood. Microtubules are not needed for steroids to affect gene expression. Lipophilic hormones diffuse across the plasma membrane of the cell. Once inside the cell, they must bind to hormone receptors. Then this hormone-receptor complex passes through the nuclear membrane Version 1
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through nuclear pores. GPCR are used with peptide hormones, not steroid hormones. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended upon analyzing each potential molecular/cellular structures to see if they are sensible interaction partners for steroid hormones. If you got the answers correct, great! If not, which answer did you choose? Did you know that microtubules are used to transport materials around cells and that steroid hormones need to move from outside the cell to inside the nucleus, so you thought that microtubules would be the answer? With special receptor proteins for transport into the nucleus, microtubules are not needed. Since hormones bind to receptors, and you knew that GPCR are hormone receptors, did you think GPCR was a correct answer? GPCR bind to peptide hormones outside the cell, not steroid hormones inside the cell. 17) B 18) B
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Clarify Question What is the key concept addressed by the question? • What is the definition of a hormone? What type of thinking is required? o This is an analyze question because you have to take the common usage of the term hormone in human or other animal bodies and expand it to regulatory molecules in other organisms. Gather Content What do you already know about hormones? What other information is related to the question? • You already know that hormones are regulatory molecules that travel through our bloodstream. But are animals with blood the only organism that utilize hormones? No, plants do as well although this is not described in this chapter. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Endocrine glands are the source of hormones, not the reverse, and yes, hormones serve a regulatory role. What is wrong with this definition is that it does not apply to hormones in plants which are not secreted by endocrine glands into blood. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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o Answering this question correctly depended upon evaluating the validity of each option. If you selected the correct answer, great! If not, what happened? Did you think that the definition is completely correct as stated because you forgot that plants use hormones as well? Did you forget that hormones are produced by endocrine glands and not the target of them (although they can be)? 19) C
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Clarify Question What is the key concept addressed by the question? • How do adrenal glands release their hormones? What type of thinking is required? o This is an evaluate question because you have to judge different possibilities for an explanation of why adrenal glands do not have a duct like other glands. Gather Content What do you already know about adrenal gland? What other information is related to the question? • You already know that the adrenal gland is part of the endocrine system. What you may not know is that the adrenal gland has one of the greatest networks of arteries and veins of any tissue of the body. Thus, the adrenal gland does not need a duct, but the hormones can diffuse directly into the capillaries. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Nerves do not transport hormones, so that answer cannot be correct. Hormones are transported via the bloodstream. The adrenal gland is a “ductless gland” that diffuses hormones into nearby capillaries. Thus, just because it does not have a duct, does not mean it will result in adrenal insufficiency. Exocrine glands release substances via ducts. As adrenal glands don’t have ducts, then they are not exocrine organs. Reflect on Process
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended understanding that adrenal glands do not have ducts, but that hormones diffuse directly through a bed of capillaries. If you got the right answer, great! If not, which answer did you choose? Did you think that the adrenal gland is an exocrine organ since it “excretes” hormones to the surrounding blood vessels? 20) E 21) B 22) B
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Clarify Question What is the key concept addressed by the question? • What hormone does licorice mimic? What type of thinking is required? o This is an evaluate question because you have to access various symptoms to see which of these systems would be produced by excess aldosterone. Gather Content What do you already know about the aldosterone? What other information is related to the question? • Black licorice inhibits an enzyme which normally limits activation of mineralocorticoid receptors. Since aldosterone is a mineralocorticoid, this mimics the effect of excess aldosterone. Aldosterone regulates blood pressure by regulating mineral balance, specifically by stimulating the kidneys to reabsorb Na+ ions and secreting K+ ions in the urine. As a result, aldosterone increases water retention and increases blood pressure. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Applying what you know, you can discount the answers concerning sexual characteristics such at infertility or excessive body hair, because aldosterone is a mineralocorticoid involved in the regulation of mineral balance and not a sex steroid hormone like testosterone. The remaining answers deal with blood pressure. So how does aldosterone affect blood pressure? It increases it by increasing blood Na+ and decreasing K+.
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended upon understanding the role of aldosterone on blood pressure and the mechanism of this regulation. Then you had to evaluate each answer to see if excess aldosterone would fit the symptom. If you selected the correct answer, great! If not, what went wrong? Did you confuse mineralocortocoids with steroid hormones? Did you think that aldosterone decreased blood pressure instead of increasing it? 23) A
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Clarify Question What is the key concept addressed by the question? • What would loss of the adrenal glands cause? What type of thinking is required? o This is an evaluate question because you have to access various symptoms to see which of these systems would be produced by the loss of aldosterone. Gather Content What do you already know about aldosterone? What other information is related to the question? • The adrenal glands produce aldosterone, so loss of these glands would result in severe loss of mineral balance within the body. Aldosterone regulates blood pressure by regulating mineral balance, specifically by stimulating the kidneys to reabsorb Na+ ions and secreting K+ ions in the urine. As a result, aldosterone increases water retention and increases blood pressure. Without aldosterone, blood pressure would drop and the brain and the rest of the body tissues would not get enough oxygen. In addition, the loss of Na+ would result in problems sending neural signals as action potentials are based on Na+ rushing into neurons. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Applying what you know, you can discount the answer concerning sexual characteristics such at infertility, because aldosterone is a mineralocorticoid involved in the regulation of mineral balance and not a sex steroid hormone like testosterone. Insulin and glucagon regulate blood sugar, not aldosterone, so that is not the correct answer. Version 1
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Aldosterone does control blood pressure and a drop in blood pressure, although might initially produce diminished cognitive function, will ultimately result in death. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended upon understanding the role of aldosterone on blood pressure and the mechanism of this regulation. Then you had to evaluate each answer to see if a lack of aldosterone would fit the symptom. If you selected the correct answer, great! If not, what went wrong? Did you confuse mineralocortocoids with steroid sex hormones? Did you think that aldosterone decreased blood pressure instead of increasing it? Did you realize that a severe drop in blood pressure would result in death since oxygen would not be delivered to the brain? 24) E 25) A 26) C
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Clarify Question What is the key concept addressed by the question? • What is a special consideration for the injection of synthetic oxytocin? What type of thinking is required? o This is an evaluate question because you have to consider the role of oxytocin in childbirth and what precautions might need to be taken while inducing labor. Gather Content What do you already know about oxytocin? What other information is related to the question? • Oxytocin induces childbirth by stimulating uterine contractions. Synthetic oxytocins, such as Pitocin, mimic the chemical structure of natural oxytocin, and thus bind to oxytocin receptors, which are Gprotein coupled receptors. Within short periods of time, the amount of oxytocin receptors and G-proteins remains stable so that shifts in hormone levels result in physiological changes. Too much oxytocin can result in uterine contractions being too strong. This could potentially harm the baby during delivery. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • You know that oxytocin is associated with childbirth and nursing, and that synthetic versions of it can induce labor and delivery via stimulating uterine contractions. You also know that oxytocin receptors are Gprotein mediated receptors and are only activated by oxytocin or analogs of oxytocin, but that G-proteins are associated with cell membranes and not transported around the bloodstream the way that hormones are. Version 1
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Thus, synthetic G-proteins do not need to be given along with synthetic oxytocin. If oxytocin can induce uterine contractions, then too much oxytocin could cause contractions that are strong enough to harm the baby. Thus, doctors must take great care with using synthetic oxytocin to induce labor. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended upon understanding the roles of oxytocin, and determining what might go wrong with it’s administration. If you got the answer correct, great! If not, where did you go wrong? Did you think that synthetic oxytocin would not be as effective as natural oxytocin? Did you remember that oxytocin receptors are G-protein mediated, and so thought that synthetic G-proteins might be needed along with the synthetic oxytocin? 27) D
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Clarify Question What is the key concept addressed by the question? • Which hormones play roles in both the ovarian cycle and sperm production? What type of thinking is required? o This is an analyze question because you have to consider the roles of a number of hormones and match those roles to the proper pair of hormones. Gather Content What do you already know about sex hormones? What other information is related to the question? • The couple is being tested for the same hormones related to conceiving a child. Luteinizing hormone (LH) stimulates ovulation and corpus leteum formation in females and stimulates the secretion of testosterone in males. Follicle-stimulated hormone (FSH) stimulates spermatogenesis in males and the development of ovarian follicles in females. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • You know that FSH is involved in both the production of sperm and eggs and that LH stimulates ovulation and testosterone secretion. Both are necessary for conceiving a child and so this is most likely the correct answer. But to make sure, let us consider the other alternatives. Insulin and glucagon are involved in the regulation of blood sugar levels. Adrenocotricotropic hormone and corticotropin-releasing hormone stimulate the release of adrenal cortical hormones such as cortisol, so it Version 1
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does not play a direct role in reproduction. Oxytocin does play a role in reproduction as it promotes uterine contraction in childbirth and milk let-down in nursing, and also promotes pair bonding and sexual arousal between mates. Although oxytocin and LH are both involved in reproduction, FSH and LH are the hormones that would most likely cause problems for conception if they were not regulated properly in both the male and female. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended upon understanding the roles of various hormones, and determining which ones might cause a problem for conception. If you got the answer correct, great! If not, where did you go wrong? Did you think that ACTH and CRH were sex hormones? Did you remember that oxytocin is involved with reproduction and can affect both male and females, and so thought that these two hormones would affect fertility? Did you forget that insulin and glucagon are involved with the regulation of blood sugar? 28) B
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Clarify Question What is the key concept addressed by the question? • What hormone is added to milk? What type of thinking is required? o This is an analyze question because you have to consider what is generally added to milk as well as the definition of a hormone. Gather Content What do you already know about hormones? What other information is related to the question? • Bovine growth hormone (BGH) has been given to cows to increase milk production and some of this hormone can end up in the milk. Vitamin D is also commonly added to milk since Vitamin D helps the intestinal absorption of calcium found in milk. What you may not know is that Vitamin D becomes a hormone after the addition of two hydroxyl groups. It is this hormone form of Vitamin D that promotes the absorption of calcium and other minerals from the intestines. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Both Vitamin A and D are added to milk. Vitamin A is added to replace loss when low-fat and reduced-fat milk is processed. Vitamin D is found naturally in milk, but milk is often fortified with additional Vitamin D to assist in the absorption of calcium. MSG (mono-sodium glutamate) is not added to milk but can be found naturally in many dairy products. Preservatives are not put in milk sold for public consumption. Instead, potential pathogens are controlled by a combination of heat treatment (pasteurization), refrigeration, and protection from light. So if Version 1
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Vitamin A and Vitamin D are the only answers that are actually added to milk, which one is a hormone (or a pre-hormone)? Vitamin D. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended upon understanding which molecules are hormones, and which molecules are added to milk. If you got the answer correct, great! If not, where did you go wrong? Did you know that Vitamin A is added to milk so think that it was the correct answer? 29) D 30) D 31) E 32) D
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Clarify Question What is the key concept addressed by the question? • Why do lampreys not need a parathyroid gland? What type of thinking is required? o This is an evaluate question because you have to consider different potential reasons why a parathyroid gland is not needed in lampreys. Gather Content What do you already know about the parathyroid gland? What other information is related to the question? • The parathyroid gland releases parathyroid hormone, which increases blood calcium levels by promoting the dissolution of calcium phosphate crystals of the bone matrix, the increased absorption of calcium by the intestines, and the reabsorption of calcium by the kidneys. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Why would lampreys not need a parathyroid gland while other vertebrates do? The parathyroid hormone regulates calcium and a large portion of calcium is usually stored in bones. Bones are something the cartilaginous lampreys do not have, thus they have less need to regulate calcium levels as vertebrates with bones. Lampreys are parasitic on other fishes, but their teeth in their circular mouths are not designed to crunch bones of their hosts, but to bite out little pieces of muscle, so they do not get considerable amounts of calcium from feeding. Reflect on Process
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended upon understanding the function of the parathyroid gland and thinking about how lampreys are different from other vertebrates. If you got the answer correct, great! If not, where did you go wrong? Did you know that lampreys are parasitic and think that they received plenty of calcium from their hosts? 33) A 34) C 35) D 36) C
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Clarify Question What is the key concept addressed by the question? • How does melatonin function? What type of thinking is required? o This is an evaluate question because you have to consider different reasons why the roommate should or should not take melatonin after thinking about the role of melatonin. Gather Content What do you already know about melatonin? What other information is related to the question? • Melatonin is produced by the pineal gland deep within the brain. It helps to regulate circadian rhythms and is activated in the dark. Thus melatonin levels are high at night and promote sleep. Thus it would be unwise to take melatonin in the morning because it would make you sleepy. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Each answer describes the effects of a different hormone. The answer referring to brittle bones may be referring to calcitonin, which inhibits loss of calcium from bone, or parathyroid hormone, which also regulates calcium by removing calcium from bone. The answer mentioning blood sugar dropping is referring to insulin, which promotes the uptake of glucose from the blood to the cells. The answer mentioning the “flightor-flight” response is referring to epinephrine or norepinephrine. The answer mentioning biological rhythms must be the correct answer since melatonin regulates circadian rhythms such as the sleep-wake cycle. Version 1
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended upon understanding the function of melatonin and thinking about the effects of taking melatonin in the morning. If you got the answer correct, great! If not, where did you go wrong? Did you remember that melatonin affects biological rhythms such as the sleep-wake cycle? Did you see how the other responses fit into the roles of other hormones? 37) E 38) C 39) D 40) C 41) A
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Clarify Question What is the key concept addressed by the question? • Which hormone needs a cell surface receptor? What type of thinking is required? o This is an analyze question because you have to consider how these hormones differ from each other and how they interact with receptors differently. Gather Content What do you already know about hormones? What other information is related to the question? • Hormones are signaling molecules that travel via the bloodstream to target tissues where they bind to receptors to initiate cellular responses. There is two types of receptor binding in hormones- binding that occurs at receptors on the cell surface and binding the occurs on intracellular receptors. Hydrophobic (or lipophilic) molecules can diffuse across the phospholipid bilayer of cell membranes. Steroid hormones are cholesterol based and can diffuse directly through cell membranes. Protein hormones such as insulin cannot; they must bind to receptors on the cell surface. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Cortisol, testosterone, estrogen, and progesterone are all steroid hormones. Thus these hormones do not need cell-surface receptors. Insulin is a protein that cannot diffuse across the cell membrane and thus needs cell-surface receptors to bind to.
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended upon understanding the function of hormone-receptor binding and realizing that some hormones can cross the cell membrane while others cannot. If you got the answer correct, great! If not, where did you go wrong? Did you forget that cortisol is a steroid hormone? Did you forget that steroid hormones can diffuse across the cell membrane and thus do not need a cell-surface receptor? 42) C 43) B 44) B 45) C 46) C 47) E 48) B 49) B 50) B 51) C 52) C 53) C 54) D 55) B
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Clarify Question What is the key concept addressed by the question? • Which hormone acts as an antagonist to the effects of atrial natriuretic hormone? What type of thinking is required? o This is an analyze question because you have to consider how one hormone stimulates opposite reactions of another hormone. Gather Content What do you already know about hormones? What other information is related to the question? • Atrial natriuretic hormone (ANH) stimulates the kidneys to excrete salt and water into the urine. The ultimate effect of this would be a reduction in blood volume and decreased blood pressure. Aldosterone increases blood pressure by promoting salt and water retention, the opposite action of ANH Choose Answer Given what you now know, what information is most likely to produce the correct answer? • As aldosterone has the opposite effects of ANH, this must be the correct answer. Cortisol is involved in long-term stress responses. Glucagon promotes the release of glucose into the blood stream. Thyroxine regulates metabolism. Progesterone completes preparation for pregnancy. Reflect on Process Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended upon understanding the function of hormone-receptor binding and realizing that some hormones can cross the cell membrane while others cannot. If you got the answer correct, wonderful! If not, which answer did you choose? Were you unclear on the roles of some of these hormones? Did you forget that aldosterone increases blood pressure by promoting salt and water retention? 56) C 57) B 58) D 59) C 60) D 61) D 62) E 63) B 64) B 65) E 66) A 67) E 68) B 69) C 70) C 71) D
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Clarify Question What is the key concept addressed by the question? • Which hormone has the fewest targets? What type of thinking is required? o This is an analyze question because you have to separately consider each hormone and list how many target tissues each one has. Gather Content What do you already know about hormones? What other information is related to the question? • Growth hormone (GH) has many targets. In fact, most cell types have GH receptors. Oxytocin primarily targets the uterus and mammary glands, but can also affect males without these structures. Melatonin targets the gonads, brain, and pigment cells. Testosterone targets male reproductive structures and many organs that effect the growth of secondary sex characteristics and puberty. Thyroid-stimulating hormone, as the name suggests, only stimulates the thyroid gland. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since all of the hormones affect multiple target tissues except thyroidstimulating hormone (TSH), then TSH must be the hormone with the fewest targets. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? Answering this question correctly depended upon understanding the targets for each of the given hormones. If you got the answer correct, wonderful! If not, which answer did you choose? Were you unclear on the targets of some of these hormones? Did you think that testosterone only affects the gonads in males or that oxytocin only affects the uterus and breasts of females? 72) A 73) C 74) A 75) D
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Clarify Question What is the key concept addressed by the question? • How do hormones target part of the body? What type of thinking is required? o This is an analyze question because you have to consider each answer for accuracy in describing how hormones deliver their signals to the appropriate target tissues. Gather Content What do you already know about hormones? What other information is related to the question? • Hormones deliver their signals through the bloodstream. As blood travels to all tissues, why don’t the hormones equally affect all tissues? It is because only tissues which express the receptors for the hormone will allow the hormone to bind and transmit the signal inside the cell. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • There are no special gateway valves in blood vessels to direct hormones to their target tissues. This would not work since multiple hormones are diffuse across all the blood, so it would be impossible to shunt blood with one hormone one direction and another hormone to another tissue. As blood flows rather quickly, there is no need for carrier proteins to move along microtubule tracks to deliver hormones. Axonal pathfinding and transport only deals with neural tissue and hormones can affect all tissue types. Thus, the answer must be that only target tissues have receptors that allow them to receive the signal.
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended upon understanding that differential expression of receptors is how hormones communicate with specific targets. If you got the answer correct, wonderful! If not, which answer did you choose? Did you know that hormones bind to receptors but not realize that receptors for specific hormones are only expressed in specific tissues? 76) D 77) C
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Clarify Question What is the key concept addressed by the question? • What gene is best for drug targeting? What type of thinking is required? o This is an evaluate question because you have to consider each potential gene to pursue as a potential therapy for hormonal deficiency and consider its benefits and drawbacks. Gather Content What do you already know about hormones? What other information is related to the question? • Hormones deliver their signals through the bloodstream. As blood travels to all tissues, they bind to either cell-surface or intracellular receptors to initiate changes in the cell.Hormones can be regulated at many levels. Genes for hormones can be regulated by transcription factors. Precursor hormone molecules are modified by enzymes to convert them into hormones. In addition, regulation can occur downstream of the hormone in a cellular pathway. While modifying all these regulatory methods could help with hormone deficiencies, supplying patients with more of the hormone itself is the most efficient means of therapy. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Peptide hormones are an attractive drug target since they are easily synthesized and become bioavailable as soon as they enter the bloodstream. Transcription factors are generally difficult to target with drugs. The enzyme is likely to be large and intracellular. The kinase is Version 1
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intracellular and likely functions in many other tissues, so targeting it may produce negative side-effects. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended upon considering different levels of regulation of hormones. If you got the answer correct, great! If not, which answer did you choose? Did you choose transcription factor since you knew that transcription is the first step in turning a peptide hormone gene into a protein? That is true, but, given a limited budget, the most direct and effective method would be to simply supply the patient with the hormone itself. 78) C
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Clarify Question What is the key concept addressed by the question? • Which company is the best partner for hormone drug development? What type of thinking is required? o This is an evaluate question because you have to consider each potential company’s comments to assess their understanding of lipophilic hormones. Gather Content What do you already know about hormones? What other information is related to the question? • Hormones deliver their signals through the bloodstream. As blood travels to all tissues, they bind to either cell-surface receptors or intracellular receptors. Lipophilic hormones can travel through the cell membrane while hydrophilic hormones such as proteins cannot cross the cell membrane and so must bind to cell-surface receptors. Since the drug that your lab developed mimics a lipophilic hormone, it will directly cross the cell membrane and interact with DNA to regulate genes. Because Company A and B mentioned needed a drug delivery system to get the drug across the cell membrane and G-protein coupled receptors that are associated with cell-surface receptors, they were showing their ignorance as to how lipophilic hormones work. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Because Company A and B mentioned needed a drug delivery system to get the drug across the cell membrane and G-protein coupled receptors that are associated with cell-surface receptors, they were Version 1
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showing their ignorance as to how lipophilic hormones work. Thus, you would want to select Company C. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended upon understanding how lipophilic hormones work. If you got the answer correct, great! If not, which answer did you choose? Did you think that lipophilic hormones would be associated with G-proteins or need some other means to get across the cell membrane? Lipophilic (or hydrophobic) molecules can readily cross the cell membrane, so such mechanisms are not needed. 79) B
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Clarify Question What is the key concept addressed by the question? • Response time of steroid drugs. What type of thinking is required? o This is an evaluate question because you have to consider each response to assess its accuracy in understanding the mode of action of lipophilic hormones. Gather Content What do you already know about hormones? What other information is related to the question? • Hormones deliver their signals through the bloodstream. As blood travels to all tissues, they bind to either cell-surface receptors or intracellular receptors. Lipophilic hormones, like steroids, can travel through the cell membrane while hydrophilic hormones such as proteins cannot cross the cell membrane and so must bind to cell-surface receptors. Since the treatment drug is a steroid, it will directly cross the cell membrane and interact with DNA to regulate genes. The process of transcription and translation take time, so the effect of the drug will not be immediate. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The drug that is being administered is a steroid. Steroid hormones cross the cell membrane to interact with DNA to regulate gene expression. No carrier protein is needed so that answer is incorrect. Similarly, no G-protein coupled receptor or downstream kinase cascade is needed, so that answer is also incorrect. Gene expression involves Version 1
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transcription of the DNA into mRNA and translation of the mRNA into protein. As this process takes some time, you should not expect the drug to have an immediate effect. Increasing the dose without giving the original dose time to have an effect could be dangerous. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended upon understanding how lipophilic hormones work. If you got the answer correct, great! If not, which answer did you choose? Did you think that lipophilic hormones would be associated with G-proteins or need some other means (like a carrier protein) to get across the cell membrane? Lipophilic (or hydrophobic) molecules can readily cross the cell membrane, so such mechanisms are not needed. Did you think that increasing the dosage would be useful? High levels of steroids in the blood are not needed for them to be effective. 80) B 81) B 82) D
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Clarify Question What is the key concept addressed by the question? • What could problems with your pituitary gland cause? What type of thinking is required? o This is an analyze question because you have to carefully examine each response to assess its accuracy in terms of describing the hypophysis. Gather Content What do you already know about the pituitary gland? What other information is related to the question? • The hypophysis is another name for the pituitary gland. The pituitary gland hangs from a stalk from the hypothalamus at the base of the brain. This gland has two parts- the anterior pituitary, or adenohypophyis, and the posterior pituitary gland, or the neurohypophysis. These two portions have different embryonic origins and secrete different hormones. Developmentally, the posterior pituitary is derived from the hypothalamus of the brain, while the anterior pituitary is derived from a pouch of epithelia tissue from the roof of the embryo’s mouth. Hormones released by the posterior pituitary gland include antidiuretic hormone and oxytocin, while the anterior pituitary gland produces adrenocorticotropic hormone, melanocyte-stimulating hormone, growth hormone, prolactin, thyroid-stimulating hormone, luteinizing hormone, and follicle-stimulating hormone. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The individual responses are like multiple True/False questions. From Version 1
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the reading you should know that the pituitary is a compound endocrine gland composed of the anterior and posterior pituitary. The posterior portion is derived from the brain and the anterior pituitary is not, thus the response linking neurological problems to the posterior is accurate. The posterior pituitary produces at least two hormones and the anterior produces at least seven hormones, so the pituitary is responsible for producing at least nine major hormones, not just one or two. As the pancreas produces insulin, and not the hypophysis, the patient should not need insulin shots. The response referring to “testable ideas about how things work” was referring to a hypothesis, not the hypophysis. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Answering this question correctly depended upon assessing each statement as to its accuracy in describing the pituitary gland. If you got the answers correct, great! If not, which answers did you choose? Did you think that the hypophysis only produce one or two hormones? It produces at least nine. Did you confuse the work hypothesis with hypophysis? Did you think that the hypophysis, or pituitary gland, produced insulin? Insulin is produced by the pancreas. 83) C
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Clarify Question What is the key concept addressed by the question? • What is the likely cause of acromegaly? What type of thinking is required? o This is an evaluate question because you have to consider each potential cause of acromegaly and decide whether it would lead to increased growth hormone. Gather Content What do you already know about growth hormone? What other information is related to the question? • Growth hormone (GH) is produced by the anterior pituitary gland and regulates the growth of muscles, bones, and other tissues. The hypothalamus produces two hormones that regulate the production of GH- growth hormone-releasing hormone (GHRH) and growth hormoneinhibiting hormone (GHIH). As the names suggest, GHRH increases GH production and GHIH decreases it. Since the patient had no growth abnormalities in her youth, her problem is something that has changed recently. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • While the patient is middle-aged and may be starting to experience menopause, hormonal shifts due to menopause do not significantly affect growth hormone or cause acromegaly. The pineal gland affects circadian rhythms in the body, not growth hormone. The anterior pituitary gland produces GH, not the posterior pituitary, so a tumor in the anterior pituitary gland could lead to an enlarged gland that produces Version 1
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more GH and lead to acromegaly. The patient was normal in her youth, which suggests that the problem is something recent, not a congenital mutation in the GH regulatory region that she was born with. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Answering this question correctly depended upon evaluating each potential cause as to its appropriateness in finding the cause of increased growth hormone and thus acromegaly. If you got the answer correct, great! If not, which answer did you choose? Did you think that GH was produced in the posterior pituitary instead of the anterior pituitary? Did you think that because the woman is middle-aged that it had something to do with menopause? 84) D
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Clarify Question What is the key concept addressed by the question? • What could cause milk production not associated with pregnancy? What type of thinking is required? o This is an evaluate question because you have to consider each potential cause of non-pregnancy related milk production. Gather Content What do you already know about the pituitary gland? What other information is related to the question? • The pituitary gland produces prolactin, which stimulates milk production in mammals. Estrogen and progesterone are also involved in the regulation of milk production, but they do so by blocking the release of prolactin. The doctor sent the patient for a brain scan, and since estrogen and progesterone are produced in the ovaries, he/she must not be concerned about any problems with the ovaries in producing this milk production. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • One of the potential responses discussed scanning the thyroid gland, potentially because the patient is not getting enough iodine. Lack of iodine leads to goiter, or an enlarged thyroid gland, which is not the symptom of the patient. LH and FSH do not stimulate milk production, but regulates ovulation in females. Thus, the most likely reason for the MRI brain scan is to rule out a pituitary tumor since prolactin, which stimulates milk production, is produced in the anterior pituitary gland.
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended upon evaluating each potential response concerning your friend’s MRI brain scan. If you got the answer correct, great! If not, which answers did you choose? Did you think that since LH and FSH regulate ovulation that they are female sex hormones that would affect milk production as well? Did you think the technician should have done a thoracic scan to look at the ovaries since they produce estrogen and progesterone, which is also involved in milk production? Remember that estrogen and progesterone, which are high during pregnancy, inhibit the release of prolactin, and thus would prevent mild production, not stimulate it. 85) A 86) D 87) B 88) D
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Clarify Question What is the key concept addressed by the question? • What do estrogen and testosterone control? What type of thinking is required? o This is an analyze question because you have to consider each answer for validity in terms of the roles of estrogen and testosterone during development. Gather Content What do you already know about estrogen and testosterone? What other information is related to the question? • Both estrogen and testosterone are produced in the ovaries and testis, as well as the adrenal glands in both sexes. Testosterone is an androgen, meaning that is stimulates the development of male characteristics, while estrogen stimulates the development of female characteristics. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • One of the answers stated that different receptor binding properties of estrogen and testosterone cause a increase in muscle mass in females compared to males. The opposite, in fact is true- testosterone stimulates greater muscle mass in males. Although society has made generalizations about what colors are preferred by males and females, there is not conclusive evidence that boys and girls inherently are attracted to different colors as infants. Male and females express estrogen and testosterone receptors in their cells differently. This difference leads to the development of sex-specific physical traits including sex organs, body hair, and breasts. Version 1
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended upon analyzing each potential answer for accuracy in terms of describing the role of testosterone and estrogen. If you got the answer correct, great! If not, which answer did you choose? Did you think that color preference was developmentally produced instead of socially instilled? Did you know that males generally have more muscle mass, but you misread the answer? 89) B
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Clarify Question What is the key concept addressed by the question? • Why does the heart produce ANH? What type of thinking is required? o This is an analyze question because you have to consider each answer for validity in terms of the role of ANH and how it relates to the heart. Gather Content What do you already know about atrial natriuretic hormone? What other information is related to the question? • Atrial natriuretic hormone (ANH) is secreted by the right atrium of the heart. ANH acts antagonistically to aldosterone, which promotes salt and water retention. Thus the effect of ANH is to increase salt and water excretion in the urine, which decreases blood volume and thus blood pressure. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Let us examine the answers. The heart is not a major endocrine gland, but it does secrete ANH. The heart is not conveniently close to the hypothalamus, which is in the brain. It is true that secretion from the heart is a convenient way for ANH to enter the bloodstream, but most hormones are released into the bloodstream via capillaries surrounding various glands located throughout the body. ANH, by increasing salt and water excretion in the urine, decreases the volume of water in the blood, which decreases blood pressure. It makes sense that stretch sensors in the atrium could respond to increased pressure by releasing ANH, which would reduce that pressure. Version 1
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended upon analyzing each potential answer for accuracy in terms of describing the role of ANH on the heart. If you got the answer correct, great! If not, which answer did you choose? Did you think that since the blood stream goes through the heart that secretion of hormones by the heart makes it easy for them to enter the bloodstream? That makes sense for ANH, which is secreted by the heart, but most hormones are not secreted by the heart, but by endocrine glands located throughout the body. ANH is not the only hormone produced by the heart. The heart also contains cells that release noradrenaline and dopamine, as well as oxytocin, although compared to the rest of the endocrine system, this is a small number of hormones. 90) A 91) B
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Clarify Question What is the key concept addressed by the question? • What intracellular event is prevented by beta-blockers? What type of thinking is required? o This is an analyze question because you have to discriminate between different potential results of using a beta-blocker. Gather Content What do you already know about G protein-coupled receptors? What other information is related to the question? • G protein-coupled receptors are found in the cell membrane and ligands outside of the cell bind to the receptors to activate G proteins located inside the cell. When activated, G proteins bind to GTP and are released from the receptor. These G proteins in turn activate secondmessenger producing enzymes to elicit changes within the cell. Such receptors are important for hydrophilic molecules such as protein hormones which cannot cross the phospholipid bilayer of the cell membrane. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Let us examine the answers. One of the answers suggests that the drug would need to get into the cell’s nucleus where it would regulate transcription. While hydrophobic molecules like steroid hormones can diffuse across the cell membrane and into the cell’s nucleus to elicit changes in gene expression, protein hormones cannot do this and so must use receptors located on the outside of the cell. G protein-coupled receptors bind to a variety of unique ligands, so can be involved in a Version 1
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number of different cellular pathways. G proteins are indeed proteins. They are enzymes that bind to GTP when active and hydrolyze it to GDP. Activated G protein activates channels or enzymes that produce second messengers likecAMP or IP3. Receptors that activate intracellular kinase domains act on the amino acids serine, threonine, and tyrosine. One of the most common is receptor tyrosine kinases (RTKs). Phosphatases remove phosphates instead of add them like kinases. Phosphatases are usually not associated with receptors. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended upon analyzing each potential answer for accuracy in terms of describing the role of G protein-coupled receptors. If you got the answers correct, great! If not, which answers did you choose? Did you think that G-proteins cross the nuclear membrane? Because proteins are usually hydrophilic, they do not readily cross membranes. Did you know that G proteins are associated with GTP, so you selected that answer? You were correct! G proteins do hydrolyze GTP to GDP, acting like an on-off switch, but it is a protein. If you selected one of the answers referring to intracellular kinase domains and phosphatase domains, they were referring to different types of receptors/enzymes and not G protein-coupled receptors. 92) D
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Clarify Question What is the key concept addressed by the question? • What intracellular molecule transmits peptide hormone signals? What type of thinking is required? o This is an analyze question because you have to discriminate between different potential signaling molecules. Gather Content What do you already know about peptide receptors? What other information is related to the question? • Peptide hormone receptors can either be a G protein-coupled receptor or a receptor kinase. G protein-coupled receptors are found in the cell membrane and ligands outside of the cell bind to the receptors to activate G proteins located inside the cell. When activated, G proteins bind to GTP and are released from the receptor. These G proteins in turn activate second-messenger producing enzymes to elicit changes within the cell. Such receptors are important for hydrophilic molecules such as protein hormones which cannot cross the phospholipid bilayer of the cell membrane. Receptor kinases, like receptor tyrosine kinases, autophosphorylate and then phosphorylate other proteins which induce cellular pathways. In both types of receptors, the intracellular cascade often involves one or a series of kinases each transferring a phosphate group onto their targets. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Nucleotides are found in DNA and RNA. Since peptide hormones do not enter the nucleus like steroid hormones do, they would not regulate Version 1
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gene expression to produce an effect. Water is anubiquitous molecule both intracellularly and extracellularly (most of the cell is composed of water). Thus, it would not make a good signaling molecule. Nitric oxide is known to act as a hormone and neurotransmitter, but it is a gas, not a peptide hormone. Amino acids are what proteins are made of, but peptide hormones do not disintegrate into amino acids to elicit their effects- the amino acids are needed to maintain the three-dimensional structure of the protein so it will fit its appropriate receptors. That leaves phosphate groups. In both types of peptide hormone receptors, G protein-coupled receptors and receptor kinases, phosphorylation, or the addition of phosphate groups to activate proteins, is involved. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended upon analyzing each potential molecular moiety for sensibility to be the most important signaling molecule for hydrophilic (peptide) hormones. If you got the answers correct, great! If not, which answer did you choose? Did you think that because peptide hormones are made of amino acids, that amino acid would be the answer? That is true, but amino acids do not break off of peptides to become signaling molecules. Since hormone regulation often leads to shifts in gene expression, did you think that nucleotide was the answer? Hormones that directly regulate DNA are hydrophobic (steroid) ones, not peptides. 93) Section Break 93.1) D
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Clarify Question What is the key concept addressed by the question? • What is the cause of species specific reactivity of hormones? What type of thinking is required? o This is an analyze question because you have to understand differences between water soluble and lipid hormones and then seek logical explanations for why mouse hormones may not affect yeast cells. Gather Content What do you already know about hormones? What other information is related to the question? • The question already tells you that you are dealing with a cell culture of yeast that you are applying a water-soluble mouse hormone to. You know that hormones can be either lipid-based or water-soluble. Lipid hormones like steroids can pass through the cell membrane while water-soluble ones cannot- they must first bind to a receptor on the outside of target cells before signal changes can be changed within the cells. Yeast receptors and mouse receptors may not be the same. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Yeast do not have cell walls like plant cells or bacteria do, so that cannot be the reason. Water-soluble hormones are not lipids, as lipids are hydrophobic and water-soluble molecules are hydrophilic. Hormones do not need to be applied in large amounts before an effect is seen, but receptors for that specific hormone is needed to Version 1
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see effects and yeast likely do name have the proper receptor for a mammalian hormone. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended on realizing that the water-soluble hormone being applied cannot diffuse across the cell membrane and thus need a proper receptor, and figuring out that yeast may not have proper receptors for mouse hormones. Did you select the correct answer? If so, great! If not, which concept did you get confused on? Did you think that water-soluble hormones are lipids that can diffuse across the cell membrane? Did you think that yeast have cell walls like bacteria? 93.2) A
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Clarify Question What is the key concept addressed by the question? • How can you improve the experiment? What type of thinking is required? o This is an evaluate question because you have to distinguish between different experimental procedures that might improve the experiment. Gather Content What do you already know about hormones? What other information is related to the question? • From the previous question you should have already determined that yeast may not have receptors specific to mouse hormones. Thus, you could solve this problem by applying the mouse hormone to a mouse cell culture instead of a yeast one. Hydrolyzing the hormone before application would destroy the three dimensional structure of the hormone so that it would not bind to its receptor properly. Applying the hormone at greater concentrations would not help if there is no receptor to bind any of the hormone. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Applying the hormone to a mouse cell culture makes sense if the hormone does not work with yeast cells as mouse cells should have the correct receptors for mouse hormones. Hydrolyzing the hormone before application would destroy the three dimensional structure of the hormone so that it would not bind to its receptor properly. Applying the hormone at greater concentrations would not Version 1
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help if there is no receptor to bind any of the hormone. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o Answering this question correctly depended on realizing that mouse cells should have receptors for mouse hormones. Did you get it right? If so, great! If not, did you think greater concentrations of hormone would help? No matter how much hormone is added, it will not affect cells that do not have receptors for it. Did you realize that hydrolyzing the hormone would destroy its structure leaving it unable to bind with receptors? 94) Section Break 94.1) A 95) Section Break 95.1) C
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Clarify Question What is the key concept addressed by the question? • What lab tests would you perform for Cushing’s syndrome? What type of thinking is required? o This is an analyze question because you have to examine each set of lab tests to see if it would be appropriate to find the source of the symptoms. Gather Content What do you already know about cortisol? What other information is related to the question? • As the question states, Cushing’s syndrome causes weight gain, excessive sweating, and muscle weakness and can be caused by high levels of cortisol. Adrenocorticotropic hormone (ACTH), produced by the anterior pituitary, stimulates the adrenal cortex to produce corticosteroid hormones including cortisol. These hormones are important in regulating glucose homeostasis and the body’s response to stress. ACTH is stimulated by corticotropinreleasing hormone (CRH) produced by the hypothalamus. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • As birth control pills usually contain analogs of estrogen and progesterone to regulate ovulation, they should not produce the effects of Cushing’s syndrome. Similarly, LH and FSH are sex hormones that should not significantly influence Cushing’s syndrome. This syndrome is caused by excessive cortisol, so cortisol blood levels should be the first lab to be performed. As Version 1
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cortisol levels are regulated by ACTH and ACTH is stimulated via CRH, all three of these molecules would be appropriate to test to find the cause of the symptoms. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended upon evaluating each group of molecules as to its appropriateness in finding the cause of Cushing’s syndrome. If you got the answer correct, great! If not, which answer did you choose? Did you think that birth control pills contained corticosteroid hormones? They do include hormones (estrogen and progesterone), but not corticosteroids. Did you forget that CRH releases ACTH? Since both CRH and ACTH regulate cortisol, then testing all three of these molecules would be needed to find the source of the problem. 95.2) A
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Clarify Question What is the key concept addressed by the question? • What regions cause too much cortisol? What type of thinking is required? o This is an analyze question because you have to examine each set of regions for MRI tests to see if it would be appropriate to find the potential tumor. Gather Content What do you already know about cortisol? What other information is related to the question? • As the question states, Cushing’s syndrome causes weight gain, excessive sweating, and muscle weakness and can be caused by high levels of cortisol. Adrenocorticotropic hormone (ACTH), produced by the anterior pituitary, stimulates the adrenal cortex to produce corticosteroid hormones including cortisol. These hormones are important in regulating glucose homeostasis and the body’s response to stress. ACTH is stimulated by corticotropinreleasing hormone (CRH) produced by the hypothalamus. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Cushing’s syndrome is produced by excess cortisol, which is produced by the adrenal cortex. The adrenal cortex is stimulated by ACTH, which is produced in the anterior pituitary. This hormone is stimulated by CRH, which is produced by the hypothalamus. If cortisol levels are extremely high, it could mean that there is a tumor any of these areas- the hypothalamus, anterior pituitary, or Version 1
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adrenal cortex. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended upon evaluating each region as to its appropriateness in finding the cause of Cushing’s syndrome- potentially caused by a tumor. If you got the answer correct, great! If not, which answer did you choose? Did you get confused as to which regions produce cortisol, ACTH, and CRH. Did you forget that CRH releases ACTH? Since both CRH and ACTH regulate cortisol, then testing all three of the regions that produce them would be needed to find the potential tumor. 96) Section Break 96.1) A
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Clarify Question What is the key concept addressed by the question? • How would juvenile hormone analog effect fleas? What type of thinking is required? o This is an analyze question because you have to discriminate between different mechanisms of action of a flea control compound. Gather Content What do you already know about juvenile hormone? What other information is related to the question? • Juvenile hormone is produced by a pair of glands near the brain of insects. High levels of juvenile hormone prevent the transformation to the adult and result in a larval-to-larval molt. If the level is low, metamorphosis will result. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Let us examine the answers. Since methoprene is a juvenile hormone analog, it should produce similar effects to that of juvenile hormone, which is the inhibition of insects to reach maturity. Thus, the fleas will not die directly, but the flea larvae will not be able to metamorphose into adults that bother your cats. This hormone does not disrupt the development of flea reproductive organs or affect the cat or its immune system. Reflect on Process Did your problem-solving process lead you to the correct Version 1
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answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Answering this question correctly depended upon analyzing each potential answer for accuracy in terms of describing the role of juvenile hormone. If you got the answer correct, great! If not, which answer did you choose? Did you think that methoprene would kill the fleas directly? Did you get confused as to the role of juvenile hormone, thinking that is sped up maturation instead of blocking it? 96.2) D
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Chapter 45 13e MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 1) The mammalian jaw is an example of what kind of moveable joint? A) hinge joint B) combination joint C) gliding joint D) ball-and-socket joint
2) As the Baby Boomer generation ages, more and more joint replacement surgeries take place each year. Hip replacement surgery is the gold standard of all joint replacement surgeries, with many patients able to walk just a few hours after surgery and return home the very next day. In contrast, knee replacement surgery usually requires hospital stays of several days, followed by weeks to months of physical therapy. What best explains why the recovery after hip replacement surgery is so much faster than after knee replacement surgery? A) The hip joint is more superficial and more accessible to surgeons than theknee joint. B) The knee joint is stabilized by many more structures (many of which have tobe cut) than the hip joint. C) The hip only moves in one direction, and recovery of one motion is easierthan recovering movement in many directions. D) The upper end ofthe thigh bone has less overall surface contact with the hip bone than itslower end has in the knee with bones of the lower leg. E) The knee is a type of combination joint, which are difficult to replace.
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3) Shown below is part of a myofibril from a relaxed muscle fiber. Which of the labeled regions will NOT shorten when the muscle contracts?
A) A band B) H band C) I band D) Sarcomere
4) In a stimulated muscle fiber, the calcium ions released by the sarcoplasmic reticulum bind to the protein _______. A) troponin B) tropomyosin C) actin D) myosin
5) You decide to do an experiment with isolated myofibrils to explore the effects of ATP hydrolysis on myofibril function. You do this by bathing the myofibrils in a solution that contains a modified form of ATP, which cannot be split into ADP and Pi. At what step will myofibril function be arrested by using this compound instead of unmodified ATP?
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A) There will be no block in the cycle, since ATP hydrolysis is not requiredfor this process. B) Myosin molecules will be unable to assemble into thick filaments. C) Myosin heads will be unable to bind to the actin filaments. D) Myosin heads willbind to the actin filaments, but the power stroke will not occur and actinfilaments will not slide over the myosin filaments. E) The myosin heads will remain attached to the actin filaments after the powerstroke.
6) The sliding filament model for muscle contraction can be studied using an isolated skeletal muscle that is fixed at each end, while a machine records the tension that is generated when the muscle is stimulated to contract. In one particular muscle tested, the length of the thick filaments was 1.6 μm and the length of the thin filaments that project in from each Z line towards the center of the sarcomere was 1.0 μm. A summary of the results comparing sarcomere length to the degree of tension produced during contraction is shown below. What most likely explains the difference between segment II and segment III of the graph?
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A) There is anincreasing overlap of the free ends of the thin filaments in segment III butnot in segment II. B) The muscle cellsused up all the ATP by the end of segment II. C) The distancebetween the Z lines is constant in segment II but rapidly increasing in segmentIII. D) Fewer myosincross-bridges are forming in segment II than in segment III. E) The length of thethick filaments is decreasing in segment III but not in segment II. F) The length of thethin filaments is decreasing in segment III but not in segment II.
7)
The structure enabling depolarization to travel deep into the muscle fiber is the ______. A) T tubule B) sarcoplasmic reticulum C) motor unit D) sarcomere
8) The neurotransmitter released from the nerve terminus at the neuromuscular junction is __________. A) troponin B) Ca2+ C) tropomyosin D) acetylcholine
9)
The use-dependent decrease in the ability of a muscle to generate force is called _____. A) tetanus B) aerobic fitness C) fatigue D) endurance
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10)
Which of the bone development lineages is incorrect? A) undifferentiatedmesenchymal cells → osteocyte → osteoblast B) undifferentiatedmesenchymal cells → fibroblast → collagen C) undifferentiatedmesenchymal cells → chondroblast → chondrocyte D) white blood cellprogenitors → monocytes → osteoclast E) undifferentiatedmesenchymal cells → osteoblast → osteocyte
11)
Which of the following regarding bone growth is false?
A) Cartilage ofgrowth plates actively grow in lengthwise direction. B) Increase in bone thickness results from the adding of bone layers on top of the periosteum. C) Some cartilage remains after it is replaced by bone. D) Cartilage calcification encroaches on the cartilaginous growth plate.
12)
One adaptation to flight in birds is lighter bones, which lack A) calcium. B) collagen. C) bone marrow. D) the periosteum. E) medullary cavities.
13)
Which of the following regarding the Haversian System is false? A) It keeps osteocytes alive. B) Haversian canals may contain nerve fibers. C) Haversian canals run parallel to the length of long bone. D) Haversian canalsare created by osteoclasts that tunnel through the bone matrix.
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14) You witness a demonstration of a martial arts master breaking a large concrete block with his hand. Besides mastering the technique, what is another benefit of the repetitive practice of breaking concrete? A) Repetitive stress on the long bones will solidify cartilage. B) The Haversiancanal system will supply more blood and strengthen the bone. C) The repetitivestress will lead to remodeling and strengthening of the long bones. D) The marrow cavity will solidify and strengthen the bone.
15)
Utilizing more motor units for stronger muscle contractions is called A) fast-twitching. B) fatigue. C) aerobic capacity. D) recruitment. E) insertion.
16)
Which of the following is the smallest unit in terms of size? A) quadriceps B) myofibril C) muscle fiber D) sarcomere E) myofilaments
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17) According to the figure, which one represents the muscle in an optimal condition for a strong contraction?
A) A B) B C) C D) D
18)
Which of the following is required to detach myosin from actin? A) calcium B) ATP C) phosphate D) troponin E) ADP
19)
In arthropods, locomotion is accomplished by muscles that work against A) each other. B) the exoskeleton. C) a hydrostatic skeleton. D) mineralized bones. E) the pseudocoel.
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20) Insects such as mosquitoes and beetles can beat their wings at tremendous speeds. This can be accomplished because A) their wing muscle contractions causes another set of muscles to stretch which in turn produces another contraction without waiting for the arrival of a nerve impulse. B) their wing muscle contractions cause another set of muscles to relax which in turn produces another wing movement. C) their wing muscle contractions are stimulated by the continuous nerve signal impulses which produce a continuous contraction of their wing muscles. D) their wing muscle contractions are capable of producing more ATP which allows these insects to have much faster and sustained wing movements. E) their wing muscle contractions produce nerve impulses which lead to more contraction of the wing muscles which in turn permits faster motion of the wings.
21)
Which animal does a dolphin or whale most resemble as it swims through water? A) A running lizard B) A running dog C) A swimming shark D) A swimmingalligator E) A swimming penguin
22)
Select the incorrect statement about muscle and muscle fibers.
A) A quickcontraction and relaxation of an isolated skeletal muscle is calledtetanus. B) Long distancerunners tend to have more slow-twitch muscle fibers than fasttwitchfibers. C) Slow-twitch muscle fibers have high concentrations of myoglobin. D) Fast-twitch fibersincrease in size with resistance training. E) Fast-twitch fibers have fewer capillaries and mitochondria than slow-twitch fibers.
23)
Select the incorrect statement related to sarcomere structure and function.
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A) Thin filaments arenot present in the H band of a sarcomere. B) Two Z linesform the opposite borders of one sarcomere. C) Stacks of thickfilaments produce dark bands, called the A band. D) I bands consistof both thin and thick filaments. E) Sacromeres are the smallest subunits of muscle contraction.
24) Which of the following statements relating to skeletal muscle and their functions is NOT correct? A) Skeletal musclesare attached to bones by tendons. B) The origin of a skeletal muscle remains relatively stationary. C) The end of the muscle called the insertion is attached to the bone that moves when the muscle contracts. D) Contraction of thehamstring muscles extends your knee. E) Muscles thatproduce opposing actions at a joint are called antagonists.
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25) In the power stroke shown in panel c below, the thin filaments are pulled towards the center of the sarcomere. What is the specific sequence of events that occurs during a power stroke?
A) Release of thephosphate group -> myosin head changes shape -> release of ADP B) Release of thephosphate group -> release of ADP -> myosin head changes shape C) Release of ADP-> myosin head changes shape -> release of the phosphate group D) Myosin headchanges shape -> release of the phosphate group -> release of ADP E) Release of ADP-> release of thephosphate group -> myosin head changes shape
26)
Which of the following joint types is not correctly matched with its example?
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A) ball-and-socket joint—femur and pelvis B) gliding joint—vertebral column C) immovable joint—skull sutures D) hinge joint—finger joint E) combination joint—knee joint
27)
In order for an earthworm to lengthen several contiguous segments of its body, it must
A) contract itscircular muscles, which pulls up the chaetae and moves the body fluid parallelto the long axis of the worm. B) contract itslongitudinal muscles, which pulls up the chaetae and moves the body fluidperpendicular to the long axis of the worm. C) contract itscircular muscles, which extends the chaetae into the surroundingsoil and moves the body fluid parallel to the long axis of the worm. D) contract itslongitudinal muscles, which extends the chaetae into the surroundingsoil and moves the body fluid parallel to the long axis of the worm. E) contract itscircular muscles, which extends the chaetae into the surroundingsoil and moves the body fluid perpendicular to the long axis of theworm.
28)
All of the following statements about exoskeletons are correct EXCEPT A) exoskeletons are made of chitin. B) muscles are attached to the exoskeleton. C) exoskeletons donot limit growth because they can stretch. D) exoskeletons are shed by many arthropods in a process called molting. E) chitin is a polysaccharide.
29) The muscles that move the eye have a high proportion of fast-twitch fibers and reach maximum tension very fast. These fibers belong to the class of __________ fibers.
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A) type I B) type II C) type III D) type IV E) type V
30) You have just read an advertisement for a new drug that claims people who take it can get muscular bodies without spending months lifting weights in the gym. The drug stimulates muscle growth in the same way that weight lifting does, which is to A) stimulate growth inthe size of existing muscle fibers. B) stimulate existingmuscle fibers to divide. C) stimulate existingmuscle fibers to fuse with one another. D) turn surroundingconnective tissue into muscle tissue. E) stimulate an increase in the proportion of slow-twitch muscle fibers.
31) In order for a muscle to contract, calcium ions released from the sarcoplasmic reticulum must bind to A) troponin. B) tropomyosin. C) myosin. D) actin. E) ATP.
32) Which of these muscles would you expect to have the greatest proportion of slow-twitch fibers? A) thegastrocnemius B) the soleus C) the lateral rectus D) chicken breast muscle
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33) Impressive was a champion Quarter Horse stallion with a magnificent muscular physique, a trait that he passed on to dozens of offspring. However, many of Impressive's offspring developed periodic muscular twitching that sometimes left the horses temporarily unable to move. Some horses even died. As it turns out, Impressive's award-winning physique was due to a mutation in a single, protein-encoding gene, resulting in hyperexcitable muscle (which contracts even in the absence of a stimulus from its motor neuron). Which is NOT a plausible explanation for the identity of the abnormal muscle protein in Impressive and his offspring? A) acetylcholinereceptors that function in the absence of acetylcholine B) leaky Na+ channels C) overactive Ca2+ pumps in the membrane of the sarcoplasmicreticulum D) tropomyosin that isunable to bind to actin E) over-active troponin molecules
34) What is the association between tropomyosin and troponin molecules in resting striated muscle fibers? A) Tropomyosin holds the troponin in place on the myosin. B) Troponin holds the tropomyosin in place on the myosin. C) Tropomyosin holds the troponin in place on the actin. D) Troponin holds the tropomyosin in place on the actin. E) There is no known association.
35)
Sustained contraction is called A) twitching. B) summation. C) tetanus. D) recruitment. E) isometric binding.
36)
Impulses conducted along the transverse tubules of the muscle fiber stimulate
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A) the release ofATP. B) the binding ofactin to the Z lines. C) tropomyosin and troponin binding. D) the release ofcalcium ions. E) the release ofacetylcholine.
37) A muscle fiber contracts by a sequence of events initiated by the binding of acetylcholine to its receptor. Which of the following is the correct sequence? I-The calcium-troponin complex pulls tropomyosin away from the myosin binding sites of actin. II-The freed-sites of actin bind to myosin to form cross bridges. III-Calcium ion binds to the troponin. A) I, III, and II B) III, II, and I C) II, III, and I D) I, II, and III E) III, I, and II
38) A newborn baby dies soon after birth because her diaphragm and rib cage muscles failed to contract and she was unable to breathe on her own. Examination of the baby’s DNA revealed that she had a genetic mutation in a gene that encoded a calcium-binding protein. Which protein was most likely defective in the baby? A) actin B) myosin C) acetylcholine D) tropomyosin E) troponin
39) The movement of actin and myosin fibers in a muscle contraction contains all of the following steps EXCEPT
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A) the myosin headattaches to the actin filament. B) myosin rolls up from one end, forming a ball. C) the myosin filament advances relative to the actin filament. D) the globular myosin head detaches from the actin filament. E) the myosin head returns to its original conformation.
40) Myofibril contractile subunits, the sarcomeres, are bounded on each end by a disc of protein called the A) H band. B) I band. C) A band. D) Z line. E) M line.
41)
A cross bridge is the binding of which two proteins? A) actin and myosin B) actin and troponin C) myosin and troponin D) collagen and troponin E) myosin and collagen
42)
Identify the condition that will result in an increased level of calcium in the blood. A) inhibition of chondroblasts B) inhibition of chondrocytes C) excess osteoclast activity D) excess osteocyte activity E) excess osteoblast activity
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43) In bone, crystals of calcium phosphate impregnate the extracellular matrix containing fibers of A) actin. B) chitin. C) collagen. D) myosin. E) troponin.
44)
Vertebrate bone does NOT ____. A) consist of cells and an extracellular matrix containing collagen fibers B) contain hydroxyapatite crystals C) contain sarcomere units D) contain blood vessels E) become remodeledwith use
45) Which of the following is/are required with actin and myosin in order to initiate muscle contraction? A) ATP B) calcium C) phosphate D) calcium and ATP E) calcium and phosphate
46)
The human skeleton is a typical vertebrate
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A) endoskeleton. B) exoskeleton. C) hydrostaticskeleton. D) axial skeleton only. E) appendicular skeleton only.
47) Impulses conducted along the muscle fiber's transverse tubules stimulate the release of calcium ions into the cytoplasm A) from the sarcoplasmic reticulum. B) from the actin and myosin subunits. C) from the Z line. D) from theextracellular fluid in the neuromuscular junction. E) from the troponin.
48) Muscle fatigue is often accompanied by muscle pain. What is the most likely explanation for this pain? A) decreased pH in themuscle fibers B) decreased levels ofglycogen in the muscle fibers C) decreased levels ofATP in the muscle fibers D) increased levels ofPi in the muscle fibers E) the myofibrilsbeing torn apart
49) of
The myofibrils consist of both thin filaments made of actin and thick filaments composed
A) myosin. B) troponin. C) chitin. D) tropomyosin. E) acetylcholine.
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50)
What molecule contributes to the red color of slow-twitch muscle fibers? A) glycogen B) lactic acid C) ATP D) myoglobin E) fatty acids
51) You are investigating the scene of a hit and run where somebody's pet dog was killed. It is a very hot day so the dog's body temperature is unlikely to yield any important information regarding the time of death. The dog's limbs are movable and there is no significant smell of rotting flesh. What is the best guess of the time of death? A) within the last 10 minutes B) within the last 2 hours C) 3-4 hours ago D) 24 hours ago
52) A lab technician is preparing to dispose of a rat and a frog that were euthanized earlier in the day for a scientific study. Although the two animals died at the same time, the rat has rigor mortis while the frog does not yet show any signs of it. What is the best explanation for this time difference in the onset of rigor mortis? A) The rat's muscleshave a greater density of myofilaments than the frog's muscles. B) The rat is ableto synthesize more ATP than the frog. C) The frog has lowerconcentrations of glycogen in its muscles than the rat. D) The rat has higherconcentrations of myoglobin in its muscles than the frog. E) All the frog's muscles are fast-twitchmuscles.
53) If you rub the scaled skin of a shark, it feels rough if you move your hand from tail to head but smooth if you move from head to tail. What is a major advantage of the scales being oriented this way?
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A) to counteract friction as the shark swims through the water B) to keep the shark afloat in the water C) to better protect the shark from predators D) to better prevent water loss from the body tissues E) to enable the shark to orient itself in space and detect prey
54) Sarin gas is an inhibitor of an enzyme that functions in the neuromuscular junction to break down acetylcholine. What is the most likely description of how a person would die after inhaling this poisonous gas? A) by a heartattack B) paralysis ofskeletal muscles C) suffocation via tetanus, or constant stimulation, of the respiratory muscles D) suffocation via paralysis, or a block in stimulation, of the respiratory muscles E) epileptic convulsions caused bydisorganized electrical activity in the brain
55) The masseter muscles originate on your cheekbones and insert into the posterior corners of the mandible (the lower jaw bone) underneath your ears. Will contraction of the masseter muscles open or close your jaw? A) close B) open
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56) The figure below represents a joint in the hind leg of a grasshopper. The exoskeleton of the leg is indicated by the two pairs of parallel black lines. A muscle that moves this leg is fixed to the skeleton at the end marked with a blue star. When the muscle contracts, it will pull on the tendon at its opposite end. Which configuration shows the most likely arrangement of the exoskeleton and a muscle that increases the flexion of this leg?
A) A B) B C) C D) D
57)
Proportional to its body length, which animal below can leap the furthest? A) horse B) human C) flea D) kangaroo E) frog F) rabbit
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58)
Based on the above diagram and other information from your text, what is the most likely (e.g., most parsimonious) explanation for the evolution of flight in vertebrates? A) Wings evolved once in vertebrates (e.g., the common ancestor of allterrestrial vertebrates had wings) and wings were subsequently lost in all butthree lineages: bats, pterosaurs and birds. B) The common ancestor of all terrestrial vertebrates was wingless and wingsevolved independently three different times: in bats, in pterosaurs and inbirds. C) The common ancestor of all terrestrial vertebrates was wingless and wingsevolved independently two different times: once in bats and once in the commonancestor of birds, pterosaurs and dinosaurs. D) The common ancestor of all terrestrial vertebrates was wingless and wingsevolved independently three different times: in bats, in pterosaurs and in thecommon ancestor of birds and dinosaurs. E) The common ancestor of all terrestrial vertebrates was wingless and wingsevolved independently three different times: in bats, in birds and in thecommon ancestor of pterosaurs and dinosaurs.
59) Imagine an earthworm that has no chaetae. How would the lack of chaetae affect movement of the earthworm? Version 1
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A) The earthworm wouldnot be able to move at all. B) The earthworm wouldonly be able to extend its body segments. C) The earthworm wouldonly be able to shorten its body segments. D) The earthwormwould have difficulty changing locations, since it cannot anchor itself inthe soil. E) The earthworm would be much flatterthan normal since it has no hydrostatic skeleton.
60) Many bird wings are more convex on the upper surface than they are on the lower surface. This enables the wing to provide greater lift because A) A. air moves moreslowly over the top surface of the wing than over the lower surface. B) B. air moves morequickly over the top surface of the wing than over the lower surface. C) C. the pressureabove the wing is greater than below the wing. D) D. the pressureabove the wing is less than below the wing. E) A and C F) B and D G) A and D H) B and C
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Answer Key Test name: Chap 45_13e_Raven 1) B 2) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the structure of the knee and hip. • What type of thinking is required? o You are being asked to apply your knowledge about the structure of the knee and hip. Gather Content • What do you know about the structure of the knee and hip? What other information is related to the question? o The hip has a wide range of motion, able to rotate in three dimensions. In contrast, the knee just moves forward and backwards. The hip has a few tendons and muscles to stabilize it and hold the ball in the socket. The knee has multiple tendons and muscles that attach to the joint and stabilize it. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o The knee joint is stabilized by many more structures (many of which have to be cut) than the hip joint. Because of this it takes longer for a patient to heal from the damage done by a knee replacement than a hip replacement. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about the structure of the knee and hip. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that the hip had less surface area in contact than the knee? Did you think that the hip has a smaller range of motion than the knee? 3) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about the structure of a myofibril. • What type of thinking is required? o You are being asked to apply your knowledge about the structure of a myofibril to identify which will not change in shape during contraction. Gather Content • What do you know about the structure of a myofibril? What other information is related to the question? o The A band is determined by the length of the thick filaments made up of myosin molecules in a sarcomere: this does not change length during a contraction. The Z lines form the borders of each sarcomere. The thin filaments are within the I bands and extend into the A bands interdigitated with thick filaments. The H band is the lighter-appearing central region of the A band containing only thick filaments. In a contracted muscle the Z lines have moved closer together, with the I bands and H bands becoming shorter. The A band does not change in size as it contains the thick filaments, which do not change in length. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o The I band, H band and sarcomere become shorter during a muscle contraction as the actin and myosin filaments slide past each other. The A band does not change in length as it is defined by the myosin thick filament. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about the structure of a myofibril to identify which will not change in shape during contraction. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that the myosin molecules in the A chain shorten during a contraction? Did you think that actin and myosin sliding across each other would not affect the I band, H band, or sarcomere length?
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Clarify Question • What is the key concept addressed by the question? o The question asks about the role of ATP hydrolysis in myofibril function. • What type of thinking is required? o You are being asked to analyze statements to explain the role of ATP hydrolysis in myofibril function. Gather Content • What do you know about the role of ATP hydrolysis in myofibril function? What other information is related to the question? o The cross-bridge cycle involves hydrolysis of ATP by myosin causing a conformational change that moves the head into an energized state. The ADP and Pi remain bound to the myosin head, which can bind to actin. In the second step, myosin binds to actin, forming a cross-bridge. In the third step, the power stroke, myosin returns to its original conformation, releasing ADP and Pi. In the last step, ATP binds to the myosin head breaking the cross-bridge. ATP hydrolysis returns the myosin head to its energized conformation, allowing the cycle to begin again. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Without ATP hydrolysis, myosin heads will be unable to bind to the actin filaments. Reflect on Process
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze statements to explain the role of ATP hydrolysis in myofibril function. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that ATP hydrolysis was necessary for breaking the bridge between actin and myosin? Did you think that ATP hydrolysis was necessary for the power stroke? 6) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about the correlation between sarcomere length and tension. • What type of thinking is required? o You are being asked to analyze statements about the correlation between sarcomere length and tension. Gather Content • What do you know about the correlation between sarcomere length and tension? What other information is related to the question? o As the sarcomere contracts, the free ends of the thin filaments approach each other as seen in segment I. Once the ends reach each other, any further contraction in sarcomere length does not increase tension (section II). As the thin filaments overlap each other, fewer actin and myosin bridges are formed and the tension of the sarcomere decreases (segment III). Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o There is an increasing overlap of the free ends of the thin filaments in segment III but not in segment II. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze statements about the correlation between sarcomere length and tension. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that the distance between Z lines in segment III are longer than in segment II? Did you think that the length of the thin filaments change during a contraction?
7) A 8) D 9) C 10) A 11) B Version 1
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12) C 13) D 14) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about the effects of stress on bone strength. • What type of thinking is required? o You are being asked to apply your knowledge about the effects of stress on bone strength. Gather Content • What do you know about the effects of stress on bone strength? What other information is related to the question? o Unlike chitin, both cartilage and bone are living tissues. Bone, particularly, can have high metabolic activity especially if bone cells are present throughout the matrix, a common condition. Bone, and to some extent cartilage, can change and remodel itself in response to injury or to physical stresses. Under a mild compressive load the bone does not bend. If the load is large enough, and the bone is not sufficiently thick, the bone will bend. Osteoblasts are signaled by the stresses in the bending section to produce additional bone. As the bone becomes thicker, the degree of bending is reduced. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o As a bone is stressed more bone is made through remodeling, strengthening the bone. Reflect on Process • Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about the effects of stress on bone strength. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that the bone marrow in the center of the bone made it stronger? Did you think that cartilage that connects bones makes them stronger? 15) D 16) E 17) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about conditions for a strong muscle contraction. • What type of thinking is required? o You are being asked to analyze which conditions would allow a strong muscle contraction. Gather Content • What do you know about conditions necessary for a strong muscle contraction? What other information is related to the question? o A contraction occurs when myosin heads bend, pulling the myosin along the actin. The more myosin and actin cross bridges the stronger the potential contraction. If the actin and myosin filaments have already slid across each other then they cannot slide much more and produce a strong contraction. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Panel A is the correct answer, because all of the myosin head groups are paired with an actin filament but the filaments have not already contracted. Panel C has very few myosin-actin cross bridges and will not be able to generate a powerful contraction. Panels B and D have already fully or partially contracted and will not be able to contract as much as the myofibril in panel A. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze which conditions would allow a strong muscle contraction. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that panel C would be able to create more force because the filaments were furthest apart? Did you think that B or D would generate a powerful contraction even though they were already partially or fully contracted?
18) B 19) B 20) A 21) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about how a whale swims. • What type of thinking is required? o You are being asked to apply your knowledge about how a whale swims. Gather Content • What do you know about how a whale swims? What other information is related to the question? o Whales, dolphins and other marine mammals have an aquatic lifestyle and have convergently evolved a similar form of locomotion. Like fish, marine mammals also swim using undulating body waves. However, unlike any of the fishes, the waves pass from top to bottom and not from side to side. This difference illustrates how past evolutionary history can shape subsequent evolutionary change. The mammalian vertebral column is structured differently from that of fish in a way that stiffens the spine and allows little side-to-side flexibility. For this reason, when the ancestor of whales reentered aquatic habitats, it evolved adaptations for swimming that used dorsoventral (top-to-bottom) flexing. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Whales and dolphins are mammals like dogs and will swim more like a dog, with an up and down movement of the backbone. Fish and reptiles swim with a side to side tail movement while birds like penguins swim by flapping their wings under water.
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about how a whale swims. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that whales would swim more like other aquatic animals such as sharks? Did you think that whales would swim like a bird using its front flippers? 22) A 23) D 24) D 25) A 26) E 27) A 28) C 29) B 30) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about how weight lifting increases muscle strength. • What type of thinking is required? o You are being asked to apply your knowledge about how weight lifting increases muscle strength. Gather Content • What do you know about how weight lifting increases muscle strength? What other information is related to the question? o Endurance training does not increase muscle size and increases the proportion of slow twitch muscle fibers. Muscle enlargement is produced only by frequent periods of high-intensity exercise in which muscles work against high resistance, as in weight lifting. Resistance training increases the thickness of fast-twitch muscle fibers, causing skeletal muscles to grow by hypertrophy (increased cell size) rather than by cell division and an increased number of cells. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Weight lifting stimulates the growth in the size of existing muscle fibers, not the number of muscle fibers. So if the drug works like weight lifting the size of existing muscle fibers will increase. The number of cells and proportion of slow-twitch muscle fibers will not increase. Reflect on Process • Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about how weight lifting increases muscle strength. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that the number of muscle fibers would increase? Did you think that the proportion of slow-twitch muscle fibers would increase? 31) A 32) B 33) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about excitation of muscles. • What type of thinking is required? o You are being asked to analyze statements about what could cause hyperexcitable muscles. Gather Content • What do you know about excitation of muscles? What other information is related to the question? o When a nerve signal reaches a muscle the neurotransmitter, acetylcholine, is released at a neuromuscular junction and then binds to acetylcholine receptors that, in turn, open Na+ channels. This causes the muscle cell membrane to depolarize. This depolarization is conducted along the muscle cell membrane and down the transverse tubules to stimulate the release of Ca2+ from the sarcoplasmic reticulum. Ca2+ diffuses through the cytoplasm to myofibrils, causing contraction. When the muscle is at rest, a long filament of the protein tropomyosin blocks the myosin-binding sites on the actin molecule. Because myosin is unable to form cross-bridges with actin at these sites, muscle contraction cannot occur. When Ca2+ binds to another protein, troponin, the Ca2+– troponin complex displaces tropomyosin and exposes the myosinbinding sites on actin, permitting cross-bridges to form and contraction to occur. o When impulses from the motor neuron cease, it stops releasing acetylcholine, in turn stopping the production of impulses in the muscle fiber. Another membrane protein in the sarcoplasmic reticulum then uses energy from ATP hydrolysis to pump Ca2+ back into the sarcoplasmic reticulum by active transport. Troponin is no longer bound to Ca2+, so Version 1
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tropomyosin returns to its inhibitory position, allowing the muscle to relax. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o A hyperexcitable muscle would be excited even in the absence of a stimulus. So if Na+ ions can cross the muscle cell membrane through a leaky Na+ channel, or if acetylcholine receptors can function in the absence of acetylcholine, this could allow the muscle to be excited in the absence of a signal. Also inactive tropomyosin or over active troponin could lead to hyperexcitability.This is because tropomyosin binds to actin preventing myosin binding in the absence of Ca2+. Alternatively when Ca2+ is present troponin displaces tropomyosin allowing actin and myosin to bind and contraction to occur. o The correct answer is that overactive Ca2+ pumps in the membrane of the sarcoplasmic reticulum would not lead to hyperexcitability as these pumps would remove Ca2+ from the muscle cell cytoplasm and decrease excitability. So an overactive Ca2+ pump would decrease muscle contractions. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze statements about what could cause hyperexcitable muscles. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that blocking the troponin/tropomyosin reaction would lead to Version 1
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hyperexcitability? Did you think that decreased Na+ movement across the membrane would lead to hyperexcitability? 34) D 35) C 36) D 37) E 38) E
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Clarify Question • What is the key concept addressed by the question? o The question asks about the proteins the bind to calcium in a muscle contraction. • What type of thinking is required? o You are being asked to apply your knowledge about that proteins the bind to calcium in a muscle contraction. Gather Content • What do you know about the proteins the bind to calcium in a muscle contraction? What other information is related to the question? o When a nerve signal reaches a muscle the neurotransmitter, acetylcholine, is released at a neuromuscular junction and then binds to acetylcholine receptors that, in turn, open Na+ channels. This causes the muscle cell membrane to depolarize. This depolarization is conducted along the muscle cell membrane and down the transverse tubules to stimulate the release of Ca2+ from the sarcoplasmic reticulum. Ca2+ diffuses through the cytoplasm to myofibrils, causing contraction. When the muscle is at rest, a long filament of the protein tropomyosin blocks the myosin-binding sites on the actin molecule. Because myosin is unable to form cross-bridges with actin at these sites, muscle contraction cannot occur. When Ca2+ binds to another protein, troponin, the Ca2+– troponin complex displaces tropomyosin and exposes the myosinbinding sites on actin, permitting cross-bridges to form and contraction to occur. Choose Answer • Given what you now know, what information is most likely to Version 1
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produce the correct answer? o When troponin binds to Ca2+ it can displace tropomyosin, allowing actin and myosin to bind and form cross bridges. Actin, myosin, tropomyosin, and acetylcholine do not bind calcium so the mutation cannot be in these proteins. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about the proteins that bind to calcium in a muscle contraction. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that actin, myosin, tropomyosin, or acetylcholine bind calcium? Did you think that a lack of troponin binding to calcium would not block muscle contraction? 39) B 40) D 41) A 42) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about release of calcium into the blood. • What type of thinking is required? o You are being asked to apply your knowledge of bone metabolism to explain an increase in calcium in the blood. Gather Content • What do you know about bone metabolism and calcium? What other information is related to the question? o Chondroblasts form cartilage and become chondrocytes or cartilage cells. Osteoblasts are bone-forming cells. When an osteoblast becomes trapped in the bone matrix it is constructing, it becomes an osteocyte, or bone cell. Osteoblasts arrange themselves along collagenous fibers in the bone and begin to secrete the enzyme alkaline phosphatase, which causes calcium phosphate salts to form in a crystalline configuration called hydroxyapatite. The crystals give the bone its hardness, but without the resilience afforded by collagen’s stretching ability, bone would be rigid but dangerously brittle. Typical bones have roughly equal volumes of collagen and hydroxyapatite, but hydroxyapatite contributes about 65% to the bone’s weight. Osteoclasts have the opposite functions as osteoblasts, and break down bone matrix, releasing calcium into the blood. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o The correct answer is that osteoclasts break down bone matrix, releasing calcium that was in the bone into the blood. Chondroblasts and Version 1
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chondrocytes are involved in cartilage production and will not affect calcium in the blood. An increase in osteoblast or osteocyte activity would pull more calcium from the blood into the bone that is being made. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge of bone metabolism to explain an increase in calcium in the blood. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that increased osteoblast or osteocyte activity would break down bone and release calcium? Did you think that decreased cartilage production would increase blood calcium? 43) C 44) C 45) D 46) A 47) A 48) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about muscle fatigue. • What type of thinking is required? o You are being asked to apply your knowledge about muscle fatigue. Gather Content • What do you know about muscle fatigue? What other information is related to the question? o Muscle fatigue refers to the use-dependent decrease in the ability of a muscle to generate force. Fatigue is highly variable and can arise from a number of causes. The intensity of contraction as well as duration of contraction are involved. In addition, fatigue is affected by cellular metabolism: aerobic or anaerobic. In the case of short-duration maximal exertion, fatigue was long thought to be caused by a buildup of lactic acid from anaerobic metabolism. More recent data also implicate a buildup in inorganic phosphate (Pi ) from the breakdown of creatine phosphate, which also occurs during anaerobic metabolism. Anaerobic metabolism produces lactic acid as a by-product. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o In fatigue, muscle cells do not receive enough oxygen to meet their needs and switch to anaerobic metabolism. A by-product of anaerobic metabolism is lactic acid production, which increases the H+ ion concentration and decreases the pH in the muscle fibers. This decrease in pH can cause a sensation of pain.
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about muscle fatigue. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that low glycogen or ATP would produce pain? Did you think that muscle was being torn in fatigue, as opposed to just not having enough energy for the muscles to contract properly? 49) A 50) D 51) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about rigor mortis. • What type of thinking is required? o You are being asked to apply your knowledge about rigor mortis. Gather Content • What do you know about rigor mortis? What other information is related to the question? o In death, the cell can no longer produce ATP, and therefore the crossbridge cycle cannot be broken—causing the muscle stiffness of death called rigor mortis. A living cell, however, always has enough ATP to allow the myosin heads to detach from actin. It takes several minutes for the cells to use up their supplies of ATP in the absence of oxygen. Once established rigor mortis will persist for about 12 hours. Decay will not begin for a day or two after death. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Rigor mortis would set in about an hour after death, since the dog is not in rigor mortis yet it probably died within the past 10 minutes. If the dog had died between 1-12 hours earlier it would be in rigor mortis. After 12 hours it would be relaxed again, but decay may start to occur. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about rigor mortis. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that rigor mortis would allow the limbs to still be moveable? Did you think that rigor mortis would not occur for 12 hours after death? 52) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about rigor mortis. • What type of thinking is required? o You are being asked to apply your knowledge about rigor mortis. Gather Content • What do you know about rigor mortis? What other information is related to the question? o In death, the cell can no longer produce ATP, and therefore the crossbridge cycle cannot be broken—causing the muscle stiffness of death called rigor mortis. A living cell, however, always has enough ATP to allow the myosin heads to detach from actin. It takes several minutes for the cells to use up their supplies of ATP in the absence of oxygen and typically a few hours for rigor mortis to occur. Once established rigor mortis will persist for about 12 hours. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Without ATP, the myosin cross-bridges in the muscles will not detach from the actin filaments and the muscles enter rigor mortis. A reduced ability to synthesize ATP or a faster rate of using it up will speed up the rate at which different muscles enter into rigor mortis. If the rat's muscles have a greater density of myofilaments than the frog's muscles, they will have more cross bridges to break and will remain in rigor mortis longer. If the rat had more myoglobin, glycogen, or ATP than the frog then it would have more of a delay in rigor mortis occurring, which is the opposite of what was observed. Version 1
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about rigor mortis. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that more myoglobin, glycogen, or ATP would increase the rate of rigor mortis? Did you think that rigor mortis had already ended in the frog? 53) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about the role of friction in movement. • What type of thinking is required? o You are being asked to apply your knowledge about the role of friction in movement to explain the orientation of scales on a shark. Gather Content • What do you know about the role of friction in movement? What other information is related to the question? o For swimming animals, the buoyancy of water reduces the effect of gravity. As a result, the primary force retarding forward movement is frictional drag, so body shape is important in reducing the force needed to push through the water. In addition to shape, the orientation of scales is important. If the scales overlap like shingles on a roof from the head to the tail, water will move over them smoothly, reducing friction. Water moving back from tail to head would encounter a rough surface producing more friction that would slow down the shark. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o The best answer is that the scales feel smooth from head to tail on the shark as that is the direction water will flow as the shark swims. This reduces friction and makes movement through the water more efficient. The orientation of the scales will not affect the rate of water loss or buoyancy. While the skin of some sharks can be used to detect prey and provide defense, there is no evidence in this question that the orientation of the scales will make a difference. Version 1
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about the role of friction in movement to explain the orientation of scales on a shark. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that buoyancy or water loss would be affected by the orientation of the shark’s scales? Did you think that the orientation of the shark’s scales would affect detection of prey or protection from predators? 54) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about the effect of inhibition of acetylcholinesterase. • What type of thinking is required? o You are being asked to analyze statements about the effect of inhibition of acetylcholinesterase to predict how sarin gas would kill a person. Gather Content • What do you know about the effect of inhibition of acetylcholinesterase? What other information is related to the question? o The motor neuron releases the neurotransmitter acetylcholine into the neuromuscular junction. Acetylcholine binds to receptors in the muscle cell membrane to open Na+ channels. The influx of Na+ ions depolarizes the muscle cell membrane causing the muscle to contract. For the muscle to relax, the enzyme acetylcholinesterase breaks down the acetylcholine, allowing the muscle cell to repolarize. If a signal cannot reach a muscle and cause contraction, this is called paralysis. If a muscle remains contracted and cannot relax this is called tetanus. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Sarin gas inhibits acetylcholinesterase, which means that acetylcholine cannot be broken down. After a nerve stimulates a muscle, the muscle will contract and will not be able to relax again. This is a state called tetanus. If this happens in the respiratory muscles after Version 1
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inhaling sarin gas then the patient will no longer be able to breathe and will suffocate. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze statements about the effect of inhibition of acetylcholinesterase to predict how sarin gas would kill a person. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that the muscle cells would not be able to contract if exposed to sarin gas, causing paralysis? Did you think that sarin gas would affect the nervous system instead of muscle contractions? 55) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about how muscles move a hinge joint like the jaw. • What type of thinking is required? o You are being asked to apply your knowledge about how muscles move a hinge joint like the jaw. Gather Content • What do you know about how muscles move a hinge joint like the jaw? What other information is related to the question? o Skeletal muscles produce movement of the skeleton when they contract. Usually, the two ends of a skeletal muscle are attached to different bones, although some may be attached to other structures, such as skin. The masseter is connected to two bones that are joined together by a hinge joint, the cheek bone and jaw bone. When the masseter contracts it generates force by pulling the two bones closer together. This causes bending to occur at the joint, thereby closing the jaw. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o When the masseter contracts, the jaw will close. You can feel the masseter contract when you close your jaw and clench your molars. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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o This question asked you to apply your knowledge about how muscles move a hinge joint like the jaw. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that when muscles contract they expand? Did you think that the muscles were oriented so they would push the two bones apart? 56) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about the orientation of a muscle in a joint. • What type of thinking is required? o You are being asked to analyze diagrams of a joint to predict how the muscles will be oriented. Gather Content • What do you know about the orientation of a muscle in a joint? What other information is related to the question? o Exoskeletal muscles produce movement of the exoskeleton when they contract. In the diagram, the exoskeleton of the leg is indicated by the two pairs of parallel black lines. The muscle that moves this leg is fixed to the skeleton at the end marked with a blue star with tendon at its opposite end. For the leg to flex or bend when the muscle contracts it will pull the two ends of the exoskeleton closer to each other as shown in A and B. The muscle is inside of the grasshopper’s exoskeleton as shown in A and C, just like your muscles are under your skin. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o The best answer is C, because it has the muscles inside of the exoskeleton and the connections to the joint are oriented so that when the muscle contracts the two ends of the exoskeleton will be pulled towards each other causing the joint to flex. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze diagrams of a joint to predict how the muscles will be oriented. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that the muscles could be outside of the exoskeleton? Did you think that the muscles would extend to push the joint causing it to flex?
57) C 58) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about the evolution of flight in vertebrates. • What type of thinking is required? o You are being asked to evaluate statements about the evolution of flight in vertebrates. Gather Content • What do you know about the evolution of flight in vertebrates? What other information is related to the question? o The evolution of flight is a classic example of convergent evolution, having occurred independently four times, once in insects and three times among vertebrates. All three vertebrate fliers modified the forelimb into a wing structure, but they did so in different ways, illustrating how natural selection can sometimes build similar structures through different evolutionary pathways. Based on the evolutionary tree, you can see that the vertebrates with and without wings are mixed, showing that the common ancestor to vertebrates did not have wings, and that wings arose three different times in bats, in pterosaurs and in birds. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o The common ancestor of all terrestrial vertebrates was wingless and wings evolved independently three different times: in bats, in pterosaurs and in birds. If the common ancestor to dinosaurs and either pterosaurs or birds had wings which were lost in dinosaurs, then the fossils of those species would have evidence of wings. This has not been seen. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to evaluate statements about the evolution of flight in vertebrates. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that the common ancestor to dinosaurs and either pterosaurs or birds had wings and then it was lost in dinosaurs? Did you think that the common ancestor to all vertebrates had wings?
59) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about the function of chaetae. • What type of thinking is required? o You are being asked to apply your knowledge about the function of chaetae. Gather Content • What do you know about the function of chaetae? What other information is related to the question? o On the underside of a worm’s body are short, bristlelike structures called chaetae. When circular muscles act, the chaetae of that region are pulled up close to the body and lose contact with the ground. Circularmuscle activity is passed backward, segment by segment, to create a backward wave of contraction. As this wave continues, the anterior circular muscles now relax, and the longitudinal muscles take over, thickening the front end of the worm and allowing the chaetae to protrude and regain contact with the ground. The chaetae now prevent that body section from slipping backward. This locomotion process involves waves of circular-muscle contraction followed by waves of longitudinal-muscle effects. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Without chaetae, the earthworm would have difficulty changing locations, since it cannot anchor itself in the soil. The chaetae are on the outside of the earthworm, while the muscles that extend and shorten body segments are inside of the earthworm. Version 1
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about the function of chaetae. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that the chaetae controlled muscle contractions? Did you think that chaetae regulated the skeleton? 60) F
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Chapter 46 13e MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 1) An animal with a gastrointestinal tract is the ___________. A) sponge B) hydra C) planarian D) earthworm E) jellyfish
2) James has been having trouble digesting lean steaks and other protein-rich foods, and these foods seem to stay in his stomach longer than usual. James is likely lacking the enzyme ____. A) pepsin B) glucagon C) bile D) lipase E) amylase
3) ___.
A baby is born without the ability to make parietal cells. This baby would not be able to
A) emulsify fats B) digestlactose C) absorb glucoseand galactose D) digest fats E) denature (unfold)milk proteins
4) Because of the hepatic portal vein, the _____ is the first organ to receive most of the products of digestion.
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A) liver B) kidney C) pancreas D) brain E) heart
5) The products of fat digestion in the small intestine are reassembled into triglycerides by the intestinal epithelium, before combining them with proteins to form ___________. A) chylomicrons B) chyme C) vesicles D) bile E) cholesterol
6)
The pancreas does NOT secrete ______. A) bile B) bicarbonate C) chymotrypsin D) lipase E) glucagon F) amylase
7)
The liver produces ________ that functions in emulsification of fats. A) trypsin B) glucagon C) insulin D) bile E) secretin
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8)
The rate at which an animal consumes energy at rest is called _______. A) the basal metabolic rate B) gluconeogenesis C) glycogenolysis D) rumination E) fermentation
9) For many people, eating is one of life’s greatest pleasures and they spend much time gathering, preparing and eating food. However, some of us would rather do other things with our time and it would be great if we did not have to eat at all. Alas, eating is a necessity. Choose the one FALSE reason why humans have to eat. A) We are heterotrophs. B) We cannot make all twenty amino acids. C) We need to replace water that we lose through sweat, breathing andurination. D) We need to obtaintrace elements such as iron in our diet. E) We need to obtainmany different vitamins in our diet. F) We need to obtain cholesterol for our cell membranes in our diet.
10) Jane and Tom are worried about their newborn baby who has just begun to nurse, but chokes and turns blue whenever she is fed. Their baby most likely has a defect in her _____. A) tonguemuscles B) soft palate C) muscle in theupper-third of her esophagus D) epiglottis E) muscle in thelower two-thirds of her esophagus
11) Saliva contains the hydrolytic enzyme, salivary amylase, which initiates the breakdown of the polysaccharide _________ into the disaccharide, maltose.
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A) cellulose B) sucrose C) glucose D) starch E) fructose
12) Most digestion in humans occurs in the first 25 centimeters of the 6-meter length of the small intestine called the _________________. A) cecum B) jejunum C) duodenum D) omasum E) colon
13) Scientists in Switzerland compared the total surface area of the small intestine in different species of bats. When the calculations were done as if the inner mucosal surface was smooth, the average inner surface area of the intestinal tube was 9.1 cm2 in one species. The mucosal surface area increased to 48 cm2 when the villi were factored in and reached a total of 0.13 m2 after adding in the membrane surface area of the microvilli. Approximately what percent of the total surface area of the small intestine in these bats can be attributed to the membrane surface area of the microvilli? A) 12% B) 28% C) 55% D) 78% E) 96%
14) Jouri has been fasting for a few days and decides to go for a short run before breaking her fast. The glucose she needs for her run will come from______________________.
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A) digestion ofstarch B) glycolysis C) insulin D) glycogenolysis E) cellularrespiration
15) The rumen of the first stomach of ruminants serves as a fermentation chamber in which bacteria and protozoa degrade A) protein. B) fats. C) cellulose. D) glucose. E) starch.
16) In horses, rodents, and lagomorphs, the digestion of cellulose by microorganisms takes place in the A) duodenum. B) reticulum. C) cecum. D) omasum. E) abomasum.
17)
The vertebrate digestive system consists of A) a one-way tube with a separate mouth and anus and accessory organs. B) a two-way tube with a separate mouth and anus. C) a tube with a single opening that serves as mouth and anus. D) a two-way tube with a separate mouth and anus and accessory organs. E) a one-way tube with a separate mouth and anus and no accessory organs.
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18)
The gastrointestinal tract does not include the ____. A) mouth B) larynx C) esophagus D) stomach E) small intestine
19) When diet and exercise has failed to produce any significant weight loss, some patients who are seriously overweight elect to have stomach surgery. A procedure galled gastric sleeve surgery removes more than half of the stomach, leaving a tube (or sleeve) about the size of a banana. Following gastric sleeve surgery, patients would have theleast trouble ____. A) eating largeamounts of food at one time B) eatingcarbohydrate-rich foods C) eatingprotein-rich foods D) eating largechunks of food of relatively hard consistency
20) The activities of cells in different layers of the tubular gastrointestinal tract are regulated by clusters of nerves located in the submucosa. These nerve complexes are called A) serosa. B) muscularis. C) plexuses. D) villi. E) epithelia.
21)
All of the following teeth are found in adult vertebrates except
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A) canines. B) premolars. C) molars. D) precanines. E) incisors.
22)
The gizzard is to a bird as the _____________ is/are to a mammal. A) teeth B) stomach C) pancreas D) liver E) cecum
23)
Food moved to the back of the mouth by the tongue causes all of the following EXCEPT
A) elevation of thesoft palate to seal off the nasal cavity. B) churning of the stomach contents. C) covering theopening of the larynx by the epiglottis. D) pressure against the pharynx to initiate swallowing. E) the swallowingcenter stimulates successive waves of muscle contraction in the esophagus.
24) Diya suffered a serious stroke that destroyed neurons in the swallowing center of her brain. This damage to her brain would prevent _____. A) peristalsis B) bolus formationby her tongue C) elevation of thesoft palate D) mastication E) secretion ofsaliva
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25) The enzyme _______ has a pH optimum most similar to peak A in the above graph. A) trypsin B) pepsin C) lipase D) salivaryamylase E) chymotrypsin F) pancreatic amylase
26) Place the processes occurring in the digestive tract in the correct order. I-Peristaltic waves of contraction propel the food along the esophagus. II-Gastric juices are secreted with the arrival of food into the duodenum. III-The acidic chyme is transferred through the pyloric sphincter. IV-HCl and pepsin begin digestion of proteins into shorter polypeptides. A) IV, III, and II B) II, III, and IV C) I, II, and III D) I, II, and IV E) II, IV, and III
27) A baby is born without the ability to make chief cells. What would be the best type of diet for this baby?
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A) a low-fat diet B) a diet low in simple sugars such as glucose and fructose C) a diet low in protein D) a diet low in complex carbohydrates such as starch E) a diet low in minerals and vitamins
28)
In humans, the surface area of the small intestine is A) 3 squarecentimeters. B) 3 squaremeters. C) 300 square meters. D) 3,000 squaremeters. E) 300,000 squaremeters.
29) The pancreas is an important accessory organ of the digestive system because it adds all of the following substances to the small intestine except A) lipase. B) trypsin,chymotrypsin. C) DNase, RNase. D) lactase. E) bicarbonate.
30) Deficiencies of brush border enzymes in the small intestine would NOT affect the complete digestion of __________. A) fats B) starch C) DNA and RNA D) sucrose E) proteins
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31)
Bicarbonate that neutralizes stomach acid is produced by the A) duodenum. B) small intestine. C) pancreas. D) large intestine. E) liver.
32) Three-year old Ben’s parents are ecstatic because he is now using the potty each time he needs to defecate. What muscle has Ben learned to control? A) the cardiacsphincter made of striated muscle B) the internal analsphincter made of smooth muscle C) the pyloricsphincter made of smooth muscle D) the external analsphincter made of striated muscle E) the Sphincter ofoddi made of smooth muscle
33) An ambulance is rushing a man to the emergency room with a knife wound. The man was stabbed in the upper-right side of his abdomen and has a large amount of internal bleeding. What vital organ has most likely been damaged by the knife wound? A) stomach B) pancreas C) heart D) liver E) appendix F) gall bladder
34) The number of chylomicrons in lymphatic capillaries of the intestine would be increased by eating _____ .
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A) lactose B) triglycerides C) sucrose D) proteins E) starch
35) Out of the estimated total of 9 liters of material passing through the small intestine, how much of it is absorbed in the small intestine? A) about 50milliliters B) about 350milliliters C) about 4.5 liters D) about 8.5liters E) all of it
36) The arrival of fat-rich chyme to the duodenum stimulates the gall bladder to contract and release _________ into the small intestine. A) cholecystokinin B) bile C) chylomicrons D) lipase E) secretin
37) Since the hepatic portal vein empties into the liver, it is able to control the amount of _________ in the blood. A) alcohol anddrugs B) toxins, pesticides,and carcinogens C) glucose D) glucose, alcohol,and drugs E) glucose, alcohol,drugs, toxins, pesticides, and carcinogens
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38)
The liver removes excess glucose from the blood and converts it into _______. A) cellulose B) maltose and otherdisaccharides C) starch D) glycogen E) bile
39)
What is NOT true about the human large intestine? A) About 4% of fluidabsorption takes place in it. B) It is longer thanthe small intestine. C) It contains threerelatively straight segments with no villi. D) Sodium, vitamin Kand other bacterial metabolic products are absorbed across its wall. E) It compacts andstores undigested materials until their excretion as feces.
40)
The secretion of pepsinogen and HCl is controlled by the hormone A) gastrin. B) pepsin. C) insulin. D) cholecystokinin. E) secretin.
41) A new mammal has been discovered in the thickly-forested mountains of Papua New Guinea. The squirrel-like animal lives in the canopy of the forest and has a diet rich in leaves. On occasion, however, the animal drops to the ground to quickly fill its cheeks with its own fecal droppings, for ingestion once it is safely back in the trees. The GI tract of this animal would most likely include ____________.
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A) a four-chamberedstomach and long intestines B) a long smallintestine with abundant villi and an appendix at the beginning of the largeintestine C) a simple stomachand a large cecum D) a short intestineand no cecum E) a simple stomach,a short small intestine and colon, and a small cecum
42) Many animals have a mutually-beneficial, symbiotic relationship with bacteria that reside in their guts. To study the effects of these relationships in more detail, research organisms such as fish and mice have been raised under germ-free conditions. What important process do you predict is compromised in germ-free mice? A) vitamin C synthesis B) vitamin D synthesis C) synthesis of essential amino acids D) vitamin K synthesis E) leptin synthesis
43)
In what way are vitamins and essential amino acids similar in human metabolism? A) They are derived from the same precursor molecules. B) Both are integralparts of membrane lipids. C) They cannot be synthesized and must be ingested. D) Both are needed to synthesize steroid hormones. E) Both contain metalions.
44) A patient with advanced colon cancer just had most of his large intestine removed. What process will be most reduced in this patient as compared to a healthy person?
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A) digestion of cellulose B) detoxification of harmful substances C) absorption of fatty acids and glycerol into lymph capillaries D) absorption of sugars and amino acids into the blood E) absorption of water into the blood
45) Which of the following represents the correct order of vertebrate gastrointestinal tract layers, going from outside the tract to inside the tract? A) the submucosa, the mucosa, the lumen, the plexuses, and the serosa B) the serosa, submucosa, and the mucosa C) the serosa, submucosa, and the lumen D) the mucosa, the plexuses, and the serosa E) the serosa, the mucosa, and the submucosa
46) Which of the following represents the correct order of adult human teeth, beginning at the front and moving right along the bottom jaw? A) incisors, molars, canines, premolars B) incisors, canines, molars, premolars C) incisors, canines, premolars, molars D) incisors, premolars, molars, canines E) canines, incisors, premolars, molars
47) In the human digestive system, the stomach produces about 2 liters of HCl and other gastric secretions every day. The acid secretion of the stomach A) is stimulated bygastrin. B) promotes a high pH. C) inhibits pepsin activity. D) begins the process of starch digestion. E) stimulates the gallbladder to contract.
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48) Gluten-free food options are becoming more and more common place due to the increased incidence and awareness of celiac disease in the US population. If a person with this disease eats foods containing gluten, the immune system responds by attacking and damaging or destroying his/her own villi. What digestive symptom would NOT be consistent with greatlyreduced numbers of villi? A) abdominal bloating and pain B) chronic diarrhea C) fatty stools D) weight loss E) peptic ulcer
49)
Select the vitamin that is matched to an incorrect deficiency symptom or disorder. A) vitamin A—night blindness B) vitamin B1—beriberi C) vitamin C—scurvy D) vitaminD—pernicious anemia E) vitamin K—severe bleeding F) vitamin B2—inflammation and breakdown of skin
50)
In the human diet, there are no "essential" ______ . A) carbohydrates B) amino acids C) vitamins D) fatty acids E) minerals
51)
A person has his/her gall bladder removed and as a result ______ .
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A) will die without agallbladder B) can now eat as much fat as desired and not absorb it C) can only eat small amounts of fat D) can only eat very small meals E) can only eat liquid meals
52)
After consuming an antacid like Rolaids, ________. A) the stomach wouldabsorb water B) HCl productionwould decrease C) the pH of thestomach fluid would decrease D) the pH of thestomach fluid would increase
53) A drop to pH 4.0 in the duodenum would primarily stimulate the release of ________________. A) cholecystokinin B) gastrin C) insulin D) pepsin E) secretin
54)
Why doesn't the stomach acid just digest right through the wall of the stomach? A) It does, we just rebuild the layers faster than they can be digested. B) Neutralizers areimbedded in the stomach lining. C) The pH of thestomach acid is not low enough to be able to digest the lining. D) Food prevents the acid from digesting the wall of the stomach. E) The lining of the stomach is protected by mucus.
55)
Which molecule is not able to be absorbed across the stomach wall?
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A) water B) alcohol C) aspirin D) glucose
56)
If a person is diagnosed with lactose intolerance, which of the following is likely? A) Eating fatty foods would be lethal. B) Eating dairy foods would be lethal. C) Digesting sugars is no longer possible. D) Eating dairy products could cause gastrointestinal pain. E) This person could only drink milk.
57) Which process in the diagram would occur the most after eating a fatty meal of french fries and ice cream? A) II B) I C) III D) II and III equally E) I and II equally
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58) Which process in the diagram causes the greatest insulin release? A) II B) III C) I D) both I and II equally E) both II and III equally
59)
After not eating for three days, _____ levels will be high. A) insulin B) glycogen C) glucagon D) blood glucose E) pancreaticenzymes
60)
What molecule is NOT involved in appetite regulation?
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A) insulin B) leptin C) secretin D) ghrelin E) neuropeptide Y F) alpha-melanocyte-stimulatinghormone
61)
Dr. Okoro has just discovered that a patient who suffers from extreme obesity has abnormal levels of two different classes of proteins that regulate appetite. Select the most-likely protein profile for this patient from the above diagram.
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A) A B) B C) C D) D
62) Langur monkeys and ruminants (such as cows) are the only known mammals in which lysozyme functions in the stomach instead of in tears and saliva. The cow/langur enzyme also has five amino acid changes that are not present in other mammals. What is most likely to be true about lysozyme from langurs and cows compared to lysozyme from other mammals? A) Salivary and tearlysozyme functions best at a higher H+ ion concentration than thecow/langur enzyme. B) The five amino acidsthat langurs and cows have in common in their lysozyme were present in thecommon ancestor of all mammals. C) These five amino acidchanges alter the specificity of the enzyme, such that the cow/langur lysozymeattacks viruses instead of bacteria. D) These five amino acidchanges somehow make the cow/langur lysozyme resistant to pepsin digestion.
63)
What digestive hormone stimulates gall bladder contraction? A) gastrin B) cholecystokinin C) gastric inhibitory peptide D) secretin E) insulin
64) The luminal contents of the same organ that secretes the hormone into the blood inhibits the further release of ______.
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A) gastrin B) cholecystokinin C) gastric inhibitorypeptide D) secretin E) insulin
65)
Pancreatic secretion of bicarbonate is stimulated by _____. A) gastrin B) cholecystokinin C) gastric inhibitory peptide D) secretin E) glucagon
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Answer Key Test name: Chap 46_13e_Raven 1) D 2) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about enzymes that digest proteins. • What type of thinking is required? o You are being asked to apply your knowledge about enzymes that digest proteins. Gather Content • What do you know about enzymes that digest proteins? What other information is related to the question? o Your body makes many digestive enzymes, including pepsin, trypsin and chymotrypsin, which digest proteins; amylase, which digests starch; and lipase, which digests fat. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Pepsin is an enzyme that digests proteins, so if James lacks this enzyme he would have digesting protein-rich foods. Amylase is used to digest carbohydrates and lipase digests lipids. Glucagon is a hormone and bile is a fluid that contains bile acids to solubilize fats. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about enzymes that digest proteins. If you got the correct answer, great job! If you got an Version 1
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incorrect answer, where did the process break down? Did you think that glucagon or bile were enzymes? Did you think that amylase or lipase digested proteins? 3) E
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Clarify Question • What is the key concept addressed by the question? o The question asks about the function of parietal cells. • What type of thinking is required? o You are being asked to apply your knowledge about the function of parietal cells. Gather Content • What do you know about the function of parietal cells? What other information is related to the question? o The stomach contains a third layer of smooth muscle for churning food and mixing it with gastric juice, an acidic secretion of the tubular gastric glands of the mucosa. These exocrine glands contain three kinds of secretory cells: mucus-secreting cells, parietal cells, which secrete hydrochloric acid (HCl), and chief cells, which secrete pepsinogen, the inactive form of the protease (protein-digesting enzyme) pepsin. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Parietal cells produce HCl and this acid helps to denature proteins in the diet. If a baby lacked parietal cells, they could not produce HCl to be secreted in the stomach, and proteins in milk that the baby consumed would not be denatured or unfolded. This would make it more difficult for the baby to digest the milk proteins. Reflect on Process • Did your problem-solving process lead you to the correct answer? Version 1
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If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about the function of parietal cells. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think parietal cells produce bile acids that help emulsify fats? Did you think that parietal cells produce digestive enzymes? 4) A 5) A 6) A 7) D 8) A 9) F
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Clarify Question • What is the key concept addressed by the question? o The question asks about essential nutrients. • What type of thinking is required? o You are being asked to apply your knowledge about essential nutrients to explain what humans do not need to consume. Gather Content • What do you know about essential nutrients in humans? What other information is related to the question? o Humans are heterotrophs who need to consume food and drink water to generate the energy and building blocks they need to survive. In addition, they need to consume essential nutrients that they cannot make on their own in sufficient levels. These include vitamins, minerals such as iron, calcium, magnesium, phosphorus, and other inorganic substances. Many vertebrates, are unable to synthesize one or more of the 20 amino acids. These essential amino acids must be obtained from food they eat. Humans require nine amino acids. In contrast, vertebrates can synthesize the lipid cholesterol, a key component of steroid hormones. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Vertebrates can synthesize the lipid cholesterol, so this does not need to be consumed. All of the other statements are true. Reflect on Process
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about essential nutrients to explain what humans do not need to consume. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that humans could not make cholesterol? Did you think that humans could make vitamins or one of the other essential nutrients? 10) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about the anatomical structure that malfunctions in choking. • What type of thinking is required? o You are being asked to analyze explanations for choking in a baby. Gather Content • What do you know about the anatomical structure that malfunctions in choking? What other information is related to the question? o Neurons within the walls of the pharynx send impulses to the swallowing center in the brain. In response, electrical impulses in motor neurons stimulate muscles to contract and raise the larynx (voice box). This pushes the glottis, the opening from the larynx into the trachea (windpipe), against a flap of tissue called the epiglottis. These actions keep food out of the respiratory tract, directing it instead into the esophagus. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o If the epiglottis does not close properly when the baby is nursing then milk will enter the lungs causing a choking reflex as the baby tries to cough the milk out of their lungs. The esophagus has muscles that move food by peristalsis and a lack of this function could cause reflux or regurgitation, but probably not choking. The tongue and palate are used in the mouth to mechanically break down food and would not contribute to choking, especially in digesting a liquid food like milk. Version 1
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze explanations for choking in a baby. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that the tongue and palate were necessary to digest a liquid food like milk? Did you think that the esophagus would be necessary to keep food out of the lungs? 11) D 12) C 13) E % MV surface area = [0.13 m2 - 48 cm2]/0.13 m2 Since 1 m = 100 cm, 1 m2 = 10,000 cm2. Equation then becomes [1300 cm2 - 48 cm2]/1300 cm2 =1252/1300 = ~96%.
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Clarify Question • What is the key concept addressed by the question? o The question asks about the relative surface area of microvilli. • What type of thinking is required? o You are being asked to analyze data to calculate the relative surface area of microvilli of the intestines. Gather Content • What do you know about microvilli? What other information is related to the question? o The epithelial wall of the small intestine is covered with tiny, fingerlike projections called villi. In turn, each epithelial cell lining the villi is covered by many folds of the plasma membrane that form cytoplasmic extensions called microvilli. The microvilli greatly increase the surface area of the intestines to allow for greater nutrient absorption. There are 100 cm in 1 m, so 1 cm = 0.01 m and 1 cm2 = .0001 m2. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o The inner surface of the intestines including villi is 48 c m2 = 0.0048 m2. Microvilli have a surface area of 0.13 m2. If you compare the area with microvilli to the total, you need to subtract the area including villi from the total area to get the area form the microvilli = 0.13-0.0048 = 0.1252 m2. Then divide this area by the total to get the percent of the area attributed to the microvilli 0.1252 m2 /0.130 m2 = 0.96 = 96%. So 96% of the area of the intestines can be attributed to the microvilli. Reflect on Process Version 1
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze data to calculate the relative surface area of microvilli of the intestines. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that you should compare the area of the total intestines to microvilli? Did you think there were 10 cm per m? 14) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about production of glucose during fasting. • What type of thinking is required? o You are being asked to apply your knowledge about production of glucose during fasting. Gather Content • What do you know about production of glucose during fasting? What other information is related to the question? o When blood glucose levels decrease, as they do between meals, during periods of fasting, and during exercise, the liver secretes glucose into the blood. This glucose is obtained in part from the breakdown of liver glycogen to glucose 6-phosphate, a process called glycogenolysis. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Glycogenolysis breaks down glycogen and releases glucose that Jouri can use during her run. Glycolysis and cellular respiration break down glucose and would lower the levels available. Insulin causes removal of glucose from the blood, which is the opposite of what Jouri needs to do. Plants store energy as starch, and if Jouri has been fasting she will not have starch in her intestines. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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o This question asked you to apply your knowledge about production of glucose during fasting. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that glycolysis, cellular respiration or insulin would increase blood glucose? Did you think that even though Jouri was fasting, she would have starch in her digestive system? 15) C 16) C 17) A 18) B 19) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about digestion in the stomach. • What type of thinking is required? o You are being asked to apply your knowledge about digestion in the stomach to predict what would happen after gastric sleeve surgery. Gather Content • What do you know about digestion in the stomach? What other information is related to the question? o Digestion of carbohydrates begins in the mouth where amylase is released from salivary glands. Digestion of proteins begins in the stomach with acid and proteases like pepsin. Digestion of lipids begins in the small intestines with bile acids and lipase. Mechanical digestion occurs through peristalsis in the stomach and small intestines. With a smaller stomach smaller meals need to be eaten. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Carbohydrate digestion begins in the mouth and will not be affected as much by a smaller stomach. Proteins are digested in the stomach. With a smaller stomach, you would need to eat smaller portions. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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o This question asked you to apply your knowledge about digestion in the stomach to predict what would happen after gastric sleeve surgery. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that proteins were not digested in the stomach? Did you think that the size of the stomach would not affect the portions of meals that could be consumed? 20) C 21) D 22) A 23) B 24) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about swallowing. • What type of thinking is required? o You are being asked to apply your knowledge about swallowing. Gather Content • What do you know about swallowing? What other information is related to the question? o Many vertebrates have teeth (figure 47.6), used for chewing, or mastication, that break up food into small particles and mix it with fluid secretions like saliva. When food is ready to be swallowed, the tongue moves it to the back of the mouth. In mammals, the process of swallowing begins when the soft palate elevates, pushing against the back wall of the pharynx (figure 47.7). Elevation of the soft palate seals off the nasal cavity and prevents food from entering it. Pressure against the pharynx triggers an automatic, involuntary response, the swallowing reflex. Because it is a reflex, swallowing cannot be stopped once it is initiated. Neurons within the walls of the pharynx send impulses to the swallowing center in the brain. In response, electrical impulses in motor neurons stimulate muscles to contract and raise the larynx (voice box). This pushes the glottis, the opening from the larynx into the trachea (windpipe), against a flap of tissue called the epiglottis. These actions keep food out of the respiratory tract, directing it instead into the esophagus. Swallowed food enters a muscular tube called the esophagus, which connects the pharynx to the stomach. The esophagus actively moves a processed lump of food, called a bolus, through the action of muscles by peristalsis.
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Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Mastication is chewing and bolus formation by the tongue are voluntary motions. Saliva secretion responds to food being placed in the mouth. Elevation of the soft palate prevents food from entering the lungs. The correct answer is that the swallowing center controls peristalsis which moves food through the esophagus Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that chewing was regulated by the swallowing center? Did you think that secretion of saliva was controlled by the brain? 25) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about enzymes that work at pH 2. • What type of thinking is required? o You are being asked to analyze the optimal pH for an enzyme. Gather Content • What do you know about optimal pH for an enzyme? What other information is related to the question? o Enzymes have an optimal pH that is typically matched to the environment in which they are active. Saliva has a pH of 7.4 and salivary amylase would have an optimal pH in this range, as seen in curve B. The pancreas secretes many digestive enzymes including trypsin and chymotrypsin, which digest proteins; pancreatic amylase, which digests starch; and lipase, which digests fat. Pancreatic fluid also contains bicarbonate, which neutralizes the HCl from the stomach and gives the chyme in the duodenum a slightly alkaline pH as seen in curve C. The stomach has a pH of 2 and the enzyme pepsin will have an optimal pH as seen in curve A. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Pepsin is active in the acidic environment of the pH with an optimal pH of 2. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze the optimal pH for an enzyme. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that the lower pH was an alkaline environment? Did you think that pancreatic enzymes were more active at an acidic than an alkaline environment?
26) E 27) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about the function of chief cells. • What type of thinking is required? o You are being asked to apply your knowledge about the function of chief cells. Gather Content • What do you know about the function of chief cells? What other information is related to the question? o The stomach contains a third layer of smooth muscle for churning food and mixing it with gastric juice, an acidic secretion of the tubular gastric glands of the mucosa. These exocrine glands contain three kinds of secretory cells: mucus-secreting cells, parietal cells, which secrete hydrochloric acid (HCl), and chief cells, which secrete pepsinogen, the inactive form of the protease (protein-digesting enzyme) pepsin. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Pepsin is used to digest proteins. If a baby cannot make chief cells then they will not be able to secrete pepsin into their stomach and will not be able to digest proteins. So they should be placed on a low protein diet. Pepsin is not used to digest carbohydrates or lipids. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about the function of chief cells. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that pepsin is used to digest carbohydrates or lipids? Did you think that chief cells were involved in nutrient absorption? 28) C 29) D 30) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about enzymes found on the brush border. • What type of thinking is required? o You are being asked to apply your knowledge about enzymes found on the brush border. Gather Content • What do you know about enzymes found on the brush border? What other information is related to the question? o The microvilli also participate in digestion because a number of digestive enzymes are embedded within the epithelial cells’ plasma membranes, with their active sites exposed to the chyme. These brush border enzymes include those that hydrolyze the disaccharides lactose and sucrose, and nucleases. Inactive proteases secreted by the pancreas are first activated by a brush border enzyme of the intestine. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Starch, sucrose and nucleic acids like DNA and RNA can be digested directly by brush border enzymes. Proteins are digested indirectly, by brush border enzymes activating trypsinogen into trypsin and chymotrypsinogen into chymotrypsin which then digest the proteins. The only molecules on the list that would not be digested by brush border cell enzymes are fats, as these cells do not release lipases. Reflect on Process
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about enzymes found on the brush border. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that brush border cells produced lipase? Did you realize that brush border cell enzymes would activate proteases? 31) C 32) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about the voluntary control of defecation. • What type of thinking is required? o You are being asked to apply your knowledge about the voluntary control of defecation. Gather Content • What do you know about the voluntary control of defecation? What other information is related to the question? o Compacted feces, driven by peristaltic contractions of the large intestine, pass from the large intestine into a short tube called the rectum. From the rectum, the feces exit the body through the anus. Two sphincters control passage through the anus. The first is composed of smooth muscle and opens involuntarily in response to pressure inside the rectum. The second, composed of striated muscle, can be controlled voluntarily by the brain, thus permitting a conscious decision to delay defecation. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Feces pass through two anal sphincters is it passes out of the body. The inner sphincter is not under voluntary control and contains smooth muscles. The outer sphincter is under voluntary control and contains striated muscles. The pyloric sphincter controls movement of food out of the stomach. There is not a cardiac sphincter, reverse flow of blood is regulated by valves.
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about the voluntary control of defecation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that the inner anal sphincter was under voluntary control? Did you think that the pyloric sphincter was in the rectum? 33) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about which organ is in the upper right side of the abdomen and has a lot of blood flow. • What type of thinking is required? o You are being asked to apply your knowledge about which organ is in the upper right side of the abdomen and has a lot of blood flow. Gather Content • What do you know about which organ is in the upper right side of the abdomen and has a lot of blood flow? What other information is related to the question? o The liver is a large organ in the upper-right side of the abdomen. To maintain blood homeostasis, the liver regulates lipid and carbohydrate levels among other metabolites. To accomplish this there is a high level of blood flow through the liver. The other organs. The gall bladder, pancreas, stomach and appendix are all in the abdomen, but do not receive as much blood flow and are not in the upper right side of the abdomen. The heart is in the thoracic cavity. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o The liver is a large organ in the upper right corner of the abdomen with a large amount of blood flow. If the man had a knife wound in this region the most likely organ involved is the liver. Reflect on Process
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about which organ is in the upper right side of the abdomen and has a lot of blood flow. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that the heart was in the thoracic cavity? Did you think that the gall bladder, pancreas, stomach or appendix were in the upper right corner of the adbomen? 34) B
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Clarify Question • What is the key concept addressed by the question? o The question asks about what chylomicrons contain. • What type of thinking is required? o You are being asked to apply your knowledge about what chylomicrons contain. Gather Content • What do you know about what chylomicrons contain? What other information is related to the question? o Fats (triglycerides) are hydrolyzed into fatty acids and monoglycerides by digestion. These fatty acids and monoglycerides are nonpolar and can thus enter epithelial cells by simple diffusion. Once inside the intestinal epithelial cells they are reassembled into triglycerides. The triglycerides then combine with proteins to form small particles called chylomicrons, which are too bulky to enter blood capillaries in the intestine. Instead of entering the hepatic portal circulation, the chylomicrons are absorbed into lymphatic capillaries, which empty their contents into the blood in veins near the neck. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Chylomicrons transport dietary fats absorbed from the intestines. If you eat more triglycerides you will produce more chylomicrons that will be transported through lymphatic capillaries. Reflect on Process
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that proteins were transported on chylomicrons? Did you think that sugars were transported on chylomicrons? 35) D 36) B 37) E 38) D 39) B 40) A 41) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about the intestinal tract of an animal that performs coprophagy. • What type of thinking is required? o You are being asked to apply your knowledge about the intestinal tract of an animal that performs coprophagy. Gather Content • What do you know about the intestinal tract of an animal that performs coprophagy? What other information is related to the question? o Rodents and lagomorphs are herbivores that have evolved another way to capture nutrients from cellulose that achieves a degree of efficiency similar to ruminant digestion. They do this by producing some feces packed with nutrients, which they then eat, a practice known as coprophagy—thus passing the food through their digestive tract a second time. The second passage allows the animal to absorb the nutrients produced by the microorganisms in its cecum. These animals are not ruminants with four chambered stomachs and instead have a simple single chambered stomach. They also have a large cecum where bacteria can break down plant material. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o An animal that eats its own feces is doing so to ingest bacteria that will break down plant material in its cecum. They will have a simple single chambered stomach and large cecum. The small intestines will be Version 1
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long to allow for absorption of the digested plant matter. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about the intestinal tract of an animal that performs coprophagy. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that these animals would be ruminants with a four chambered heart? Did you think that the animals would have a small cecum? 42) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about essential nutrients can be made by bacteria in the intestines. • What type of thinking is required? o You are being asked to apply your knowledge about essential nutrients can be made by bacteria in the intestines. Gather Content • What do you know about essential nutrients can be made by bacteria in the intestines? What other information is related to the question? o All mammals rely on intestinal bacteria to synthesize vitamin K, which is necessary for the clotting of blood. Vitamin C must be consumed, while vitamin D can be consumed or made by the skin. Essential amino acids by definition cannot be made in sufficient levels and need to be eaten. Leptin is a hormone that is made in adipose tissue. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o The best answer is that all mammals rely on intestinal bacteria to synthesize vitamin K. The other answers are either not essential, or must be consumed and are not made by intestinal bacteria. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about essential nutrients can be made by bacteria in the intestines. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that leptin could not be made by animals? Did you think that essential amino acids could be made by an animal? 43) C 44) E
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Clarify Question • What is the key concept addressed by the question? o The question asks about the function of the large intestine. • What type of thinking is required? o You are being asked to apply your knowledge about the function of the large intestine. Gather Content • What do you know about the function of the large intestine? What other information is related to the question? o After food enters the stomach, the food passes to the small intestine, where a battery of digestive enzymes continues the digestive process. The products of digestion, together with minerals and water, are absorbed across the wall of the small intestine into the bloodstream. What remains is emptied into the large intestine, where some of the remaining water and minerals are absorbed. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o The primary function of the large intestines is to absorb water. If the large intestines were removed the patient would become dehydrated as not enough water would return to the blood. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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o This question asked you to apply your knowledge about the function of the large intestine. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that sugars or fatty acids were absorbed in the large intestines? Did you think that cellulose was digested in the large intestines? 45) B 46) C 47) A 48) E
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Clarify Question • What is the key concept addressed by the question? o The question asks about the function of villi. • What type of thinking is required? o You are being asked to analyze symptoms that would occur in a patient with damaged villi due to celiac disease. Gather Content • What do you know about the function of villi? What other information is related to the question? o The epithelial wall of the small intestine is covered with tiny, fingerlike projections called villi. In turn, each epithelial cell lining the villi is covered by many folds of the plasma membrane that form cytoplasmic extensions called microvilli. Absorption of fats and sugars occur through these epithelial cells. Damage of the epithelial cells on the villi would decrease absorption of fats and sugars leading to weight loss. The fats would leave the body in the feces, resulting in fatty stools. The sugars would draw water into the intestines through osmosis, leading to diarrhea, abdominal bloating and pain. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Peptic ulcers are caused by Heliobacter pylori infections and not by celiac disease. Reflect on Process • Did your problem-solving process lead you to the correct answer? Version 1
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If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze symptoms that would occur in a patient with damaged villi due to celiac disease.. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that peptic ulcers are caused by bacteria? 49) D 50) A 51) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about the function of the gall bladder. • What type of thinking is required? o You are being asked to apply your knowledge about the function of the gall bladder. Gather Content • What do you know about the function of the gall bladder? What other information is related to the question? o The gall bladder contains bile acids made by the liver. The bile acids are released into the small intestines after a fatty meal. The bile acids help to emulsify and break down fats so they can be digested and absorbed more readily. If a person without a gall bladder eats too much fat, it will cause a fatty stool which is similar to diarrhea. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Without a gall bladder a patient cannot secrete bile acids into the small intestine to help break down and absorb fats. As a result they would be put on a low fat diet. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about the function Version 1
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of the gall bladder. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that a person could eat as much fat as they wanted to because it would not be absorbed? Did you think that the gall bladder was associated with the size of the stomach which would affect the portion size of meals the patient could consume? 52) D 53) E
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Clarify Question • What is the key concept addressed by the question? o The question asks about a hormone secreted in response to acid. • What type of thinking is required? o You are being asked to apply your knowledge about a hormone secreted in response to acid. Gather Content • What do you know about a hormone secreted in response to acid? What other information is related to the question? o The major enterogastrones include cholecystokinin, secretin, and gastric inhibitory peptide. Chyme with high fat content is the strongest stimulus for CCK and GIP secretions, whereas increasing chyme acidity primarily influences the release of secretin. Pepsin is a digestive enzyme secreted into the stomach. Insulin is a blood hormone made by the pancreas. Gastrin and pepsin are made by the stomach. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Chyme is acidic and lowers the pH of the duodenum to 4. This stimulates the release of secretin. Gastrin and pepsin are not made in the duodenum, they are made in the intestine. Insulin is made in the pancreas. Cholecystokinin is released in the duodenum, but in response to high fat content. Reflect on Process • Did your problem-solving process lead you to the correct answer? Version 1
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If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about a hormone secreted in response to acid. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that insulin, gastrin, or pepsin were released into the duodenum? Did you think that cholecystokinin was released in response to low pH? 54) E 55) D 56) D 57) A
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Clarify Question • What is the key concept addressed by the question? o The question asks about the digestion of fats. • What type of thinking is required? o You are being asked to apply your knowledge about the digestion of fats. Gather Content • What do you know about the digestion of fats? What other information is related to the question? o French fries and ice cream both contain lots of fat (panel II). French fries also contain starch (panel III). Panel I is the digestion of proteins into amino acids that are absorbed into the blood stream. Panel III is the digestion of starch into glucose which is also absorbed into the blood stream. Panel II is the digestion of fats which are packaged into chylomicrons and secreted into the intestinal lymph. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Given that both French fries and ice cream contain fat and panel II shows the digestion of fats, the best answer is panel II. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about the digestion of fats. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that ice cream and French fries both contain a lot of protein or starch? Did you think that panel II was the digestion of protein or starch?
58) B
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Clarify Question • What is the key concept addressed by the question? o The question is asking which type of food most greatly affects the release of insulin. • What type of thinking is required? o You are being asked to evaluate three different scenarios as to their impact on insulin release. Gather Content • What do you know about the release of insulin? What other information is related to the question? o Insulin is released in the body in response to an increase in blood glucose levels. Eating a meal higher in carbohydrates would trigger more insulin to be released into the bloodstream. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o Panel I represents a meal higher in proteins (with the blue balls representing amino acids) and so this meal would be less likely to cause the body to release insulin. Likewise, panel II represents a meal high in fatty acids(with the larger yellow globules representing fatty acids) and so this meal would be less likely to cause the body to release insulin. The hexagon structures in panel III represent a string of glucose molecules. A meal high in these carbohydrates would trigger the greatest release of insulin in the body. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to evaluate three different meals and predict which would trigger the greatest release of insulin. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you incorrectly identify the contents of the different meals in the panels? Did you forget that insulin is associated with the digestion of glucose molecules and so the greatest amount of insulin would be release in response to meals higher in carbohydrates (glucose molecules)?
59) C
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Clarify Question • What is the key concept addressed by the question? o The question asks about the effects of fasting on hormones. • What type of thinking is required? o You are being asked to apply your knowledge about the effects of fasting on hormones. Gather Content • What do you know about fasting? What other information is related to the question? o After person fasts, their blood glucose levels decrease and the liver secretes glucose into the blood. Insulin levels drop as blood glucose drops. This glucose is obtained in part from the breakdown of liver glycogen to glucose 6-phosphate, a process called glycogenolysis. The breakdown of liver glycogen is stimulated by another hormone, glucagon, which is secreted by the α (alpha) cells of the islets of Langerhans in the pancreas. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o During fasting, glycogen, blood glucose and insulin levels all drop. Pancreatic enzymes are not needed to digest food, and also decrease. Glucagon levels increase to stimulate glycogen break down and release of glucose into the blood. Reflect on Process • Did your problem-solving process lead you to the correct answer? Version 1
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If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to apply your knowledge about the effects of fasting on hormones. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that glycogen, blood glucose or insulin levels would increase? Did you think that pancreatic enzymes would be needed to break down food? 60) C 61) D
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Clarify Question • What is the key concept addressed by the question? o The question asks about hormones that regulate appetite. • What type of thinking is required? o You are being asked to analyze data to explain which hormones that regulate appetite could lead to obesity. Gather Content • What do you know about hormones that regulate appetite? What other information is related to the question? o Leptin is secreted by adipose tissue and binds to leptin receptors in the hypothalamus. When leptin levels are high, they indicate that the animal is well fed and lead to a cessation of eating. The hormones GIP and CCK have receptors in the hypothalamus and seem to send the same kind of inhibitory signals to the brain as leptin. The gut hormone ghrelin has the opposite effect of these appetite-suppressing hormones. Ghrelin also has receptors in the hypothalamus, but ghrelin appears to stimulate food intake. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o A decrease in hormones or their receptors that indicate an animal is well fed would increase feeding and obesity. Similarly an increase in hormones or their receptors that indicate that an animal needs to eat would lead to obesity. The combination proteins that would lead to obesity is example D – Ghrelin is increased which would stimulate feeding and leptin receptor is decreased which would remove some of the signals that an animal was well fed and did not need to eat more. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze data to explain which hormones that regulate appetite could lead to obesity. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you realize that for obesity to occur proteins that suppress feeding would need to be inactivated? Did you realize that for obesity to occur proteins that stimulate feeding would need to be activated?
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Clarify Question • What is the key concept addressed by the question? o The question asks about the convergent evolution of lysozyme. • What type of thinking is required? o You are being asked to analyze statements to explain the convergent evolution of lysozyme. Gather Content • What do you know about the convergent evolution of lysozyme? What other information is related to the question? o A remarkable case of convergent evolution at the molecular level is exhibited by ruminants and the langur monkey, which subsists primarily on leaves. In most mammals, lysozymes are enzymes found in saliva and tears, which attack invading bacteria. However, in both ruminants and langurs, lysozymes have been modified to take on a new role, digesting bacteria in the stomach. In both cases, five identical amino acid changes have evolved. The result is that the lysozyme molecules of ruminants and langurs are more similar to each other than they are to lysozymes in more closely related species. Choose Answer • Given what you now know, what information is most likely to produce the correct answer? o The stomach contains an acidic environment and the digestive enzyme pepsin, while tears and saliva do not. The tear and saliva lysozyme would be predicted to function better at lower H+ than the cow/langur enzyme. There is no evidence that specificity of lysozyme switched to viruses instead of bacteria. If the common ancestor to cows and langurs had these mutations in common then you would predict to see it in other Version 1
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species. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o This question asked you to analyze statements to explain the convergent evolution of lysozyme. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that an acidic environment had lower H+ ion concentrations? Did you think that the common ancestor to cows and langurs had the mutations observed? 63) B 64) A 65) D
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Chapter 47 13e MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 1) Most simple invertebrates obtain their oxygen by diffusion directly from the surrounding A) air. B) water. C) mud. D) blood.
2)
Fish and crustaceans are similar in that both use _____________ for gas exchange. A) lungs B) tracheal tubes C) the walls of themantle cavity D) gills E) the moist surfaceof their skin
3) The large number of alveoli in mammalian lungs, the numerous lamellae in fish gills, the papulae of echinoderms, and the extensive tracheal system of insects are all adaptations that optimize what factor in the formula for Fick’s Law of Diffusion? A) D B) Δp C) d D) A
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4)
In the graph shown here, what does the A represent? A) anatomical dead space B) air that helps keep the alveoli inflated (open) after forced exhalation C) air that is not used for gas exchange D) air with a concentration of oxygen higher than that of air outside the body E) air from a previous breath that does not mix with newly-inhaled air of the next breath
5)
Each breath is initiated by neurons in the "respiratory control center" located in the A) spinal cord. B) larynx. C) cerebellum. D) medullaoblongata. E) carotid body.
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6) In tissue capillaries, __________ combines with water to form carbonic acid, which after being transported to the lungs, dissociates back to its constituents. A) CO2 B) O2 C) H2CO3 D) hemoglobin E) HCO3-
7) Chemoreceptors located in the aortic and carotid bodies stimulate the respiratory control center in the brain when the blood __________ decreases. A) PO2 B) PCO2 C) hemoglobinconcentration D) HCO3- concentration E) pH
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8)
In the graph shown here, curve _______ is most likely the oxygen-binding curve for normal adult human hemoglobin, curve _______ is most likely that of llama hemoglobin (from a llama population that has lived in the mountains of Peru for thousands of years), and curve _______ is most likely that of myoglobin. A) A; B; C B) A; C; B C) B; A; C D) B; C; A E) C; B; A
9) Ciliated gills in clams, sharks continuously swimming with their mouths partly open, countercurrent flow of blood and water in fish gills, and the use of air sacs to effect unidirectional flow of air through bird lungs are all adaptations that optimize what factor in the formula for Fick’s Law of diffusion?
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A) D B) Δp C) d D) A
10) Imagine that you have been transported light years away to another planet with waterfilled oceans. This distant planet has a barometric pressure of 1,000 mm Hg at sea level and air that contains 15 percent O2. Would you take in much more oxygen, much less oxygen, or about the same amount of oxygen per breath on this planet as you would on Earth? A) much less oxygen on the distant planet B) much more oxygen on the distant planet C) about the same amount of oxygen as on Earth
11) The general term that describes the uptake of oxygen from the environment and the disposal of carbon dioxide at the body system level is A) cellularrespiration. B) inspiration. C) exhalation. D) respiration. E) diffusion.
12)
The exchange of gases across a respiratory surface always occurs by A) facilitated transport. B) active transport. C) diffusion. D) bulk flow. E) osmosis.
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13) Tim, who is an avid cyclist, is struck by a car during an organized bike ride. Two of his ribs are broken, puncturing his chest wall on the right side. What will most likely happen to his lungs? A) Both lungs willcollapse. B) Both lungs willoverinflate. C) His left lung will beokay, but his right lung will collapse. D) His left lung willbe okay, but his right lung will overinflate. E) His right lung willoverinflate and his left lung will collapse. F) His right lung willcollapse and his left lung will overinflate.
14) What would a graph of internal lung pressure compared to atmospheric pressure look like during one inhalation/exhalation cycle in a frog?
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A) A B) B C) C D) D E) E
15) The most efficient lungs with respect to oxygen uptake are found in this group of vertebrates. A) amphibians B) birds C) fish D) mammals E) reptiles
16)
The oxygen content of dry air in the atmosphere A) is about78.1%. B) is about 21.0%. C) is about 0.03%. D) varies depending on the altitude. E) is inverselyproportional to the partial pressure of oxygen.
17) Fick's law of diffusion states that the rate of diffusion of a gas across a membrane depends on all of the following except A) the membranesurface area. B) the concentrationdifference of the gas on the two sides of the membrane. C) the width of themembrane. D) the size of thegas molecule. E) which membranetransport proteins are present.
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18) The external gills of an adult axolotl are not as efficient as fish gills because___________. A) water flows overthe axolotl gills at many different angles B) blood flowsthough the axolotl gills more slowly than through fish gills C) axolotl gills arenot highly branched D) axolotl gills are covered by thick layers of cells E) axolotls are slow swimmers and all fish swim fast to ventilate theirgills
19) Where a given species of vertebrate lives has dramatically shaped the evolution of respiratory adaptations, particularly since the oxygen concentration in air is approximately 20 times that of the oxygen concentration in water. Per unit area of gas exchange surface, which group of vertebrates can extract the greatest total amount of oxygen from the external medium? A) amphibians B) birds C) fish D) mammals E) reptiles
20) Four-year old Sammy is having a temper-tantrum. In a final attempt to get his way, he yells to his mom, “I'm gonna hold my breath ‘til I die!” What is the primary reason that Sammy’s mom is unconcerned by this statement? A) Sammy is too young to hold his breath for more than 30 seconds. B) It is impossible forSammy to control the contraction of his diaphragm and intercostal muscles sincethey are made up of smooth muscle. C) As Sammy holds hisbreath, the decreasing levels of oxygen in his blood will lead to stimulationof the respiratory control center in his brain. D) As Sammy holds hisbreath, the increasing levels of carbon dioxide in his blood will lead tostimulation of the respiratory control center in his brain.
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21) When is the PO2 an especially strong stimulant of the respiratory control center in the brain of healthy individuals? A) whilehyperventilating B) whilehypoventilating C) while running aroad race along the shoreline of Vancouver D) while climbing tothe summit of Mt. Everest E) while free-divingto a coral reef 60 feet below the surface of the sea
22)
Which blood vessels carry oxygenated blood? A) pulmonaryarteries B) pulmonaryveins C) systemic veins(such as the femoral vein in your leg)
23) What is the likely outcome if you were able to force water through fish gills in the opposite direction to how it normally flows over the gills? A) The blood's oxygenconcentration would not be able to exceed 50%. B) Gas exchange wouldbe inhibited and movement of oxygen into the blood would cease. C) The direction ofblood flow would reverse through the gills to compensate for the reverseddirection of water flow. D) The movement ofcarbon dioxide from the blood into the water would increase. E) There would be noeffect, and maximal oxygenation of blood would still occur.
24) What change would increase the rate of oxygen diffusing from lung alveoli into the blood? A) An increase in the hemoglobin concentration of the red blood cells B) A decrease in the partial pressure of oxygen in the alveoli C) An increase in the partial pressure of oxygen in the blood entering thelungs D) A decrease in the pH of the blood entering the lungs E) An increase in the humidity of air in the lungs
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25) that
One possible reason that there are not any really large insects currently living on Earth is
A) gas exchangeacross their moist skin surfaces cannot support the metabolic needs of a largebody. B) their lungs never evolved to be as highly branched as a mammal's. C) their gills do nothave as many lamellae as fish gills. D) the bulk flow ofair through their tracheal tubes would be more difficult the larger the bodyand longer the tracheal tubes. E) they do not haveas many papulae as echinoderms.
26) During your dissection of a fish, what structure would you have to remove to see the gills? A) operculum B) spiracle C) jaw bone D) glottis E) trachea
27) In the countercurrent exchange in a fish's gills, the oxygen concentration is always _______ in the water than the blood along the entire pathway of each lamella. A) higher B) lower C) the same
28)
Which of these animals uses positive pressure breathing?
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A) amphibians B) reptiles C) birds D) mammals
29) Which group of animals has one-way flow of air through its lungs, whereas all the others have tidal flow? A) birds B) amphibians C) mammals D) reptiles
30) During an asthma attack, allergens trigger the release of histamine, which causes severe constriction of the __________________. A) bronchi B) pleuralcavities C) larynx D) trachea E) rib cage
31) The gas exchange surfaces in a mammalian lung are organized into structures that look like clusters of hollow grapes. The hollow, grape-like structures are the________________. A) spiracles B) lamellae C) alveoli D) papulae E) bronchi
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32)
The respiratory systems of fish and birds are similar in that both______________. A) employ countercurrentexchange. B) utilize air sacs. C) have unidirectionalflow of the environmental medium over the gas exchange surfaces. D) have similar partialpressures of oxygen in the environmental medium.
33) A major genetic cause of emphysema is deficiency of the protein alpha-1 anti-trypsin (AAT). AAT is an enzyme that inhibits the activity of another protein. What protein is most likely the normally-inhibited target of AAT? A) carbonic anhydrase B) collagen C) elastin-specific protease D) hemocyanin E) hemoglobin F) myoglobin
34) In the future, it may be possible to screen for a number of different types of cancer by a simple blood test. If a blood test indicates a very early stage of lung cancer, where is the most likely place that the tumor will be growing? A) in the wall of alarge bronchus B) in the wall ofan alveolus C) in the wall of apulmonary vein D) in thevisceral pleural membrane E) in theparietal pleural membrane
35) Tom is choking on a piece of steak that is stuck in his trachea, and he signals for his young son to call 911. It takes the paramedics four minutes to reach his house. Will this be in time to save Tom (and why), or will Tom already be dead (and why)?
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A) Tom will be alive since the myoglobin in his muscles will release oxygeninto the blood after he stops breathing. B) Tom will be dead due to the lowered pH of his blood. C) Tom will be alive since he had a reserve of about three-quarters of hishemoglobin still bound to oxygen when he started choking. D) Tom will be dead since all the hemoglobin in his arterial blood will unloadits oxygen during the first pass through the tissues after his last breath.
36)
Which dissolved gas cannot be transported by hemoglobin? A) nitric acid (NO) B) oxygen (O2) C) carbon dioxide (CO2) D) carbon monoxide (CO) E) nitrogen (N2)
37) The primary advantage of gills versus the body surface for gas exchange in aquatic animals is that ________. A) gills are located near the mouth B) all gills containa countercurrent exchange system C) gills have a much greater diffusion surface area D) gills decreaseresistance to movement
38)
What respiratory adaptation was important for the invasion of land by arthropods? A) cutaneous respiration in moist habitats B) positive pressure breathing to increase gas exchange C) the ability to close spiracles to prevent water loss D) countercurrent exchange surrounding the trachea E) gas- andwater-permeable exoskeletons
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39)
Humans cannot survive long at altitudes greater than 6000 m because ________. A) alveoli becomecompressed at the lower atmospheric pressures B) there is much moreCO2 in the atmosphere at the higher altitudes than at sealevel C) the partial pressure of O2 becomes less than half that at sea level D) the diaphragm cannot be contracted enough to produce a full breath
40) Soft-shelled turtles can remain submerged underwater for several hours without ventilating their lungs because ______. A) they also have rudimentary gills B) the partialpressure of O2 is higher underwater C) they can use cutaneous respiration through the soft lining of their throats D) they can store some air in special air sacs under the shell
41) Major evolutionary changes have resulted in anatomical and physiological adaptations that optimize the rate of gas exchange in animals by each of these factors except ________. A) increasing thesurface area for diffusion B) increasing the concentration difference driving diffusion C) decreasing the distance for diffusion D) increasing thediffusion constant for each gas
42) Most phyla of aquatic invertebrates have improved the rate of gas exchange by creating a water current over their respiratory surfaces, thereby _____. A) decreasing the distance for diffusion B) increasing the surface area for diffusion C) increasing the concentration difference D) changing the diffusion constant
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43)
The large number of alveoli in lungs improve gas exchange by _____. A) decreasing the distance for diffusion B) increasing the surface area for diffusion C) increasing the concentration difference D) changing the diffusion constant
44)
The many lamellae in the gills of fish improve respiratory efficiency by ______. A) decreasing thedistance for diffusion B) increasing the surface area for diffusion C) increasing the concentration difference D) changing the diffusion constant
45) The close proximity of capillaries to the alveoli in lungs improve respiratory efficiency by ______. A) decreasing the distance for diffusion B) increasing the surface area for diffusion C) increasing the concentration difference D) changing the diffusion constant
46) The North American pronghorn antelope can run almost as fast as a cheetah, but unlike the cheetah, can also sustain speeds of 30-40 mph for miles. The pronghorn is about the size of a large, domestic goat. You would predict the antelope to have a _____ than the goat. A) smaller trachea B) higherconcentration of hemoglobin C) smaller lungvolume D) lower concentrationof myoglobin E) lower concentrationof bicarbonate
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47) If each human lung contains about 300 million alveoli with a summed total surface area for gas exchange of 40 square meters, what is the approximate surface area of a single alveolus? A) 0.133 square micrometers B) 1.33 square micrometers C) 133 squaremillimeters D) 7.5 squaremicrometers E) 7.5 squaremillimeters F) 750 squaremicrometers
48) What is the order of structures or spaces that a surgeon will pass through to operate on a human lung? A) skin ->intercostal muscles -> parietal pleural membrane -> pleural cavity-> visceral pleural membrane -> lung tissue B) skin ->intercostal muscles -> pleural cavity -> parietal pleural membrane-> visceral pleural membrane -> lung tissue C) skin ->visceral pleural membrane -> intercostal muscles -> pleural cavity-> parietal pleural membrane -> lung tissue D) skin ->intercostal muscles -> visceral pleural membrane -> pleural cavity-> parietal pleural membrane -> lung tissue E) skin -> pleural cavity ->intercostal muscles -> visceral pleural membrane -> parietal pleuralmembrane -> lung tissue
49)
During exhalation, the diaphragm _______. A) contracts andmoves down B) relaxes and movesup C) relaxes and movesdown D) contracts and moves up
50)
Which part of a hemoglobin molecule binds to a molecule of O2?
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A) the surface of anα globin chain B) the surface of aβ globin chain C) the iron atom inthe center of a heme group D) the copper atomwedged between an α and a β globin chain E) the hydrophobicpocket between two α chains
51)
In which PO2 environment would hemoglobin most easily release its O2? A) 40 mm Hg B) 65 mm Hg C) 75 mm Hg D) 90 mm Hg E) 100 mm Hg
52) During exercise, the blood returning to a person's heart contains hemoglobin that is about ______ saturated. A) 3% B) 22% C) 35% D) 75% E) 97%
53) Every winter, many individuals tragically die in their sleep due to faulty heaters that leak carbon monoxide (CO) during the night. How does CO poisoning lead to death? A) CO binds more tightly to carbonic anhydrase than does carbon dioxide. B) CO binds to oxygen, and the CO-oxygen complex cannot bind to hemoglobin. C) CO coats the surfaces of the alveoli, preventing diffusion of oxygen intothe blood. D) CO inhibits the chemosensitive neurons in the aortic and carotid bodies. E) CO binds more tightly to hemoglobin than doesoxygen.
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54) Protruding papulae on the surface of echinoderms improve respiratory efficiency by ______. A) decreasing the distance for diffusion B) increasing the surface area for diffusion C) increasing the concentration difference D) changing the diffusion constant
55)
The axolotl, an aquatic amphibian, uses ______ for gas exchange. A) internal gills B) external gills C) lungs D) trachealtubes E) papulae
56)
Ram ventilation is used by _____ during respiration. A) frogs B) tuna C) whales D) penguins E) salamanders
57)
Air enters human lungs from the mouth by passing through the ________. A) trachea B) nasal cavities C) spiracles D) posterior air sacs E) esophagus
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Answer Key Test name: Chap 47_13e_Raven 1) B 2) D 3) D
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Clarify Question What is the key concept addressed by the question? • This question is asking you to identify the components of Fick’s Law of Diffusion. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the understanding of how vertebrate structures factor into Fick’s Law of Diffusion. Gather Content What do you already know about gas exchange? What other information is related to the question? • Alveoli, the sites of gas exchange in mammalian lungs, are sacs that are surrounded by capillaries. • Lamellae are extensions in fish gills where gas exchange occurs. • Papulae, or skin gills, in echinoderms are extensions of the body that allow gas exchange to occur. • The tracheal system of insects is a series of tubes that facilitate gas exchange. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Alveoli, lamellae, paulae, and tracheal systems all provide extra surface area over which gas exchange can occur. • The area over which gas exchange occurs is represented by “A” in the formula for Fick’s Law of Diffusion.
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use vertebrate structures in a new situation. If you got an incorrect answer, did you remember that each of the mentioned structures increases surface area, or that surface area is a component of Fick’s Law of Diffusion? Did you have trouble extending the nature of the vertebrate structures to determine the correct answer? 4) B Bracket C represents theresidual volume, which is the volume of air in the lungs that cannot be expelled even with a forced exhalation. In addition to helping keep the alveoli from collapsing, the residual volume enables gas exchange to continue between breaths.
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Clarify Question What is the key concept addressed by the question? • This question is asking you to interpret the function of volume of air that is not exhaled from the lungs. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the retention of air in the lungs. Gather Content What do you already know about the lungs? What other information is related to the question? • Gas exchange occurs in the alveoli of the lungs. • Alveoli are small sacs that must remain filled with air to maintain their shape and function. • Tidal volume is the volume of air that is inhaled and exhaled during quiet breathing. • Vital capacity is the maximum exhalation that can occur after a maximum inhalation. • Vital capacity is less than the total lung volume; some air always remains in the lungs. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • When air is inhaled, it mixes with the air that is present in the lungs so gas exchange can occur. • Dead anatomical space refers to space where gas exchange does not occur. • Air inside the lungs would have an oxygen level that is equal to or less than that outside of the body. • A volume of air is always maintained inside the lungs so that alveoli remain inflated. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the concept of lung volumes in a new situation. If you got an incorrect answer, did you remember that alveoli are the sites of gas exchange, or that a volume of air always remains in the lungs? Did you have trouble extending the nature of alveoli to determine the correct answer? Version 1
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5) D 6) A 7) E 8) E
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Clarify Question What is the key concept addressed by the question? • This question is asking you to interpret oxygen dissociation curves. What type of thinking is required? • Analyze level: o This question is asking you to identify key factors that qualify something as hemoglobin or myoglobin. Gather Content What do you already know about myoglobin and hemoglobin? What other information is related to the question? • As altitude increases in mountainous regions, available oxygen levels decrease. • Myoglobin is found in muscle cells. • The affinity of myoglobin for oxygen is much higher than that of hemoglobin. • When hemoglobin has been depleted of oxygen, in the same circumstance myoglobin will still have oxygen. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • This graph shows oxygen saturation increasing on the Y axis, and available oxygen available increasing on the X axis. • When comparing the three curves, example “A” has the highest oxygen saturation (60%) at PO2 of 20mmHg. This is characteristic of myoglobin. • Example “B” has a moderate amount of oxygen saturation (approximately 25%)at PO2 of 20mmHg. This is characteristic of hemoglobin, and since this is a moderate value for these three curves, it would represent the llamas in a mountainous environment. Organisms such as the llamas in this example have less oxygen available, so they may have increased RBC counts to deliver more oxygen to the tissues. • Example “C” has the lowest oxygen saturation (approximately 10%) at PO2 of 20mmHg. This is characteristic of hemoglobin in an organism does not live not at an extreme altitude. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: Version 1
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o Answering this question correctly depended not only on distinguishing between hemoglobin and myoglobin, but also on your ability to break down, or analyze, oxygen dissociation curves. If you got an incorrect answer, did you remember that components of hemoglobin include a lower affinity for oxygen than myoglobin, or that atmospheric pressure can affect oxygen saturation? Did you have trouble breaking down the differences between myoglobin and hemoglobin to determine the correct answer?
9) B
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Clarify Question What is the key concept addressed by the question? • This question is asking you to identify the components of Fick’s Law of Diffusion. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the understanding of how vertebrate structures factor into Fick’s Law of Diffusion What type of thinking is required? Gather Content What do you already know about diffusion? What other information is related to the question? • Diffusion is the movement of a substance from high concentration to low concentration. • The greater the difference between the area of high concentration and low concentration, the faster diffusion occurs. • In the gas exchange that occurs to sustain life, oxygen diffuses from an area of high concentration in the environment to an area of low concentration in the organism. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Ciliated gills in clams place blood near water, where oxygen can be taken up. • The continual swimming with an open mouth exhibited by sharks insures that a steady stream of water with a relatively high oxygen Version 1
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content will flow past the gills, which contain blood with a lower oxygen content. • These adaptations would maximize delta p, which is the difference in pressure between the environment and the location of gas exchange. • As delta p increases, gas exchange occurs more rapidly. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use vertebrate structures in a new situation. If you got an incorrect answer, did you remember that each of the mentioned structures maximize the difference between blood oxygen levels and the oxygen levels of the environment, or that the difference in these levels is a component of Fick’s Law of Diffusion? Did you have trouble extending the nature of the vertebrate structures to determine the correct answer? 10) C
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Clarify Question What is the key concept addressed by the question? • This question is asking you to recognize the atmospheric conditions on Earth. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break atmospheric gas composition and atmospheric pressure into their component pieces to understand how they function. Gather Content What do you already know about earth’s atmosphere? What other information is related to the question? • Dry air on Earth is 20.95% oxygen. • Barometric pressure at sea level on Earth is 760 mmHg. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The oxygen content and atmospheric pressure of the planet in this question are not identical to the conditions found on Earth, but they are similar. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: Version 1
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o Answering this question correctly depended not only on distinguishing between oxygen content and atmospheric pressure, but on your ability to analyze these conditions in a novel setting. If you got an incorrect answer, did you remember that components of the oxygen content of Earth’s atmosphere is 20.95%, or that atmospheric pressure at sea level is 760mmHg? Did you have trouble breaking down the conditions on Earth to determine the correct answer? 11) D 12) C 13) C
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Clarify Question What is the key concept addressed by the question? • This question is asking you to extrapolate the effects of an injury to the chest. What type of thinking is required? • Apply level: o You are being asked to take what you already know and apply it to predict the consequences of an injury. Gather Content What do you already know about the respiratory passages? What other information is related to the question? • Air travels from the nose and/or mouth down the pharynx and larynx, and into the trachea. The trachea splits into the left and the right bronchus, which carry air separately into the lungs. • Broken ribs can result in the puncture of a lung if the ribs are pushed inward during trauma. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • If Tim’s right chest wall has been compromised by the accident, collapse of his right lung could occur. Unless the trauma went through to the left side of the chest, his left lung would be unaffected. Overinflation of the lungs would not occur. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the anatomy of the lungs in a new situation. If you got an incorrect answer, did you remember that the function of one lung is not dependent on the function of the other lung, or that an injury to one lung can result in the collapse of that lung? Did you have trouble extending the anatomy of the lungs to determine the correct answer? 14) C
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Clarify Question What is the key concept addressed by the question? • This question is asking you to identify the specifics of pressure changes in frog respiration. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break the mechanics of amphibian respiration and corresponding pressure changes into their component pieces to understand how they function. Gather Content What do you already know about respiration in a frog? What other information is related to the question? • Frogs breathe by positive pressure breathing. • Positive pressure breathing involves forcing air into the lungs by pushing air from the mouth into the lungs. • Elastic recoil of the lung tissue pushes air back out of lungs and the pressure drops as air leaves the lungs. • This breathing can be seen externally as the underside of the frog’s mouth and throat moves with each breath. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • To initiate a breath, a frog increases pressure to force air into the lungs. • The lungs expand as air is forced in. • Pressure decreases as the lungs release air. • Air pressure in the lungs thus increases steadily, then decreases steadily. The pressure is never negative. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between frog respiration and the respiration of other animals, but on your ability to break down, or analyze, the mechanics of frog respiration. If you got an incorrect answer, did you remember that components Version 1
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of frog respiration include positive pressure changes, or that frog respiratory pressure changes are not negative? Did you have trouble breaking down the mechanics of frog breathing to determine the correct answer?
15) B 16) B 17) E 18) A
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Clarify Question What is the key concept addressed by the question? • This question is asking you to compare the gills of an axolotl to the gills of a fish. What type of thinking is required? • Apply level: o You are being asked to take what you already know and apply it to the efficiency of axolotl gills. Gather Content What do you already know about axolotl gills? What other information is related to the question? • Axolotl gills are located around the neck of the animal. • These gillsmust be moved constantly to ensure that gas exchange will occur. • Axolotl gills are highly branched, and this external branching creates drag on the animal and slows its locomotion. • The branching of gills creates multiple directions of water flow over the gills. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • While axolotls do move relatively slowly, some fish swim slowly as well. • Axolotl gills are highly branched, but they are not covered with a thick layer of cells. • Blood flow through axolotl gills is not slower than blood flow through fish gills. Version 1
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• Axolotl gill efficiency is lowered by the lack of consistent flow of water over the gill structures. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use axolotl gill structure in a new situation. If you got an incorrect answer, did you remember that axolotl gills are external, or that axolotls must move water over their gills for gas exchange to occur? Did you have trouble extending the anatomy of axolotl gills to determine the correct answer? 19) B 20) D
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Clarify Question What is the key concept addressed by the question? • This question is asking you to explain the regulation of breathing. What type of thinking is required? Choose from the following samples to streamline your writing: • Apply level: o You are being asked to take what you already know and apply it to the involuntary initiation of breathing. Gather Content What do you already know about respiration? What other information is related to the question? • A normal child that voluntarily holds his or her breath does not suffocate, as breathing resumes within a few seconds. • The respiratory control center stimulates an individual to take a breath. • As carbon dioxide accumulates in the blood, the pH of the blood decreases. • A decrease in the pH of the blood is detected by chemoreceptors, which in turn stimulate the respiratory control center to initiate a breath. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The diaphragm and intercostal muscles are skeletal muscles, not smooth muscles, and are therefore under voluntary control. • It is changing carbon dioxide levels, not changing oxygen levels, that stimulate the respiratory control center. • As Sammy holds his breath, carbon dioxide would build up, and pH would decrease. Decreased pH would stimulate the respiratory control Version 1
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center and Sammy would take a breath. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the regulation of breathing in a new situation. If you got an incorrect answer, did you remember that breathing is stimulated by the respiratory control center, or that increased carbon dioxide lowers pH and stimulates the respiratory control center? Did you have trouble extending the regulation of breathing to determine the correct answer? 21) D 22) B 23) A
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Clarify Question What is the key concept addressed by the question? • The question is asking you to apply what you know about fish respiration a new situation. What type of thinking is required? • Apply level: o You are being asked to take what you already know apply, it to the reversal of water flow over fish gills. Gather Content What do you already know about fish gills? What other information is related to the question? • Water flows from the gill arch over the gill filaments. • The direction of water is the opposite of the direction of blood flow. • The countercurrent nature of the water and blood flow allows efficient gas exchange to occur, since equilibrium of oxygen levels cannot be reached. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • If water flow was reversed so that water and blood ran in the same direction in a fish gill, diffusion of oxygen would stop when the water and blood reached equal oxygen levels, which would be 50% oxygen in each. Once that point is reached, not further diffusion of oxygen would occur. Reflect on Process
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the principles of fish respiration in a new situation. If you got an incorrect answer, did you remember that the opposing nature of water flow in fish gills is necessary to maximize gas exchange, or that changing the direction of water flow would remove this advantage? Did you have trouble extending the principles of fish respiration to determine the correct answer? 24) A
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Clarify Question What is the key concept addressed by the question? • This question is asking you to identify the variable that affects oxygen diffusion. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break diffusion and the composition of blood into their component pieces to understand how they function. Gather Content What do you already know about diffusion? What other information is related to the question? • Diffusion is a passive process that is driven by difference in concentration between two regions. • The greater the difference in concentrations between the two regions, the faster diffusion will occur. • Diffusion is the movement of a substance from high to low concentration. • Oxygen diffuses from the alveoli of the lungs into the blood. • Hemoglobin binds with oxygen and carries it through the circulatory system to the tissues. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Increasing hemoglobin would cause an increased uptake of oxygen in the alveoli. • Lower concentrations of oxygen in the blood would speed up the rate Version 1
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of diffusion from the alveoli. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between X and Y, but on your ability to break down, or analyze, the factors that affect diffusion. If you got an incorrect answer, did you remember that hemoglobin has an affinity for oxygen, or that the binding of oxygen to hemoglobin would lower the concentration of oxygen in the alveoli? Did you have trouble breaking down the factors that affect diffusion to determine the correct answer? 25) D
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Clarify Question What is the key concept addressed by the question? • This question is asking about the factors that limit insect body size. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to understand insect body size limitations. Gather Content What do you already know about respiration in insects? What other information is related to the question? • Insects do not possess lungs. • Air moves through the body of an insect passively through tracheal tubes. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Insects do not have papulae, or lungs, or gills, or exchange of gases through the skin. • As an insect increases in size, the air has to travel a greater distance to reach the tissues. • Since there is no active process that drives air to the tissues, air travels less efficiently as distance increases. • One size reaches a critical point, air cannot be transported efficiently to the tissues. This would limit the growth of an insect. Reflect on Process
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use insect respiration in a new situation. If you got an incorrect answer, did you remember that insect respiration does not involve gills or lungs, or that movement of air is passive? Did you have trouble extending insect respiration to determine the correct answer? 26) A 27) A 28) A 29) A 30) A 31) C 32) C 33) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about the conditions that result in emphysema. What type of thinking is required? • Apply level: o You are being asked to take what you already know and apply it to the genetic causes of emphysema. Gather Content What do you already know about emphysema? What other information is related to the question? • Breathing requires expansion and recoil of breathing structures such as the lungs and the alveoli. • Emphysema is a disease that makes breathing very difficult. • Emphysema can be caused by a genetic mutation, but is most often caused by cigarette smoking. • Emphysema involves the break down of the walls of alveoli. • Emphysema results in a greater number of larger alveoli. • The lungs of someone with emphysema become less elastic, and moving air becomes much more difficult. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Hemocyanin is similar to hemoglobin, but it is characteristic of molluscs. • Myoglobin and hemoglobin bind with oxygen, but are not involved in the physical mechanics of breathing. • Similarly, carbonic anhydrase converts carbon dioxide and water into Version 1
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bicarbonate, but is not involves in the mechanics of breathing. • Collagen is a critical protein for the structure and function of the lungs. • Proteases are enzymes that break down protein, so elastin-specific protease would break down elastic proteins and would contribute to emphysema. This enzyme would need to be inhibited to prevent these changes from occurring. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the nature of normal lung structure in a new situation. If you got an incorrect answer, did you remember that the structure of lungs is dynamic, or that emphysema results in a loss of this elasticity? Did you have trouble extending the nature of lung structure to determine the correct answer? 34) A 35) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about whether humans can survive the lack of oxygen for any period of time. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to a situation in which oxygen deprivation occurs for a short time. Gather Content What do you already know about oxygen transport? What other information is related to the question? • Blockage of the trachea prevents oxygen from reaching the lungs. • As the final electron acceptor in cellular respiration, oxygen is critical for survival. • Hemoglobin carries oxygen to the tissues from the lungs. • At rest, most of the oxygen that is bound to hemoglobin remains in the blood. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Myoglobin binds with oxygen and stores it muscle tissue. This oxygen is used within muscle, but is not released back into the blood. • Although increased carbon dioxide in the blood does lower pH, the effects of this change would take longer to become fatal than lack of oxygen. • The majority of oxygen does remain bound to hemoglobin, which creates a limited reserve if breathing is interrupted. Version 1
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the nature of hemoglobin in a new situation. If you got an incorrect answer, did you remember that hemoglobin carries oxygen in the blood, or that hemoglobin does not immediately release all of the oxygen that it carries? Did you have trouble extending the nature of hemoglobin to determine the correct answer? 36) E 37) C 38) C 39) C 40) C 41) D 42) C 43) B 44) B 45) A 46) B
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Clarify Question What is the key concept addressed by the question? • This question is asking you to identify the physiological basis for sustained running. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to explain the sustained running speed of a large mammal. Gather Content What do you already know about oxygen use? What other information is related to the question? • Cellular respiration provides the energy that is necessary for all activities, including running. • Oxygen is necessary for cellular respiration to occur. • Oxygen binds to hemoglobin and is transported to cells through the circulatory system. • Myoglobin binds to oxygen and stores in muscle tissue. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • A smaller lung volume and a smaller trachea would reduce the available oxygen, and subsequently the potential for more cellular respiration. • A lower concentration of myoglobin would also reduce available oxygen. • Bicarbonate is a molecule that transports carbon dioxide; it is not involved in making oxygen available for cellular respiration. Version 1
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• A higher concentration of hemoglobin would increase the amount of oxygen that could be transported to cells, and thereby the amount of energy available for activity. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the nature of energy that is available for use in a new situation. If you got an incorrect answer, did you remember that oxygen is required to produce usable cellular energy, or that hemoglobin carries oxygen? Did you have trouble extending the requirements for cellular respiration to determine the correct answer? 47) A 1 meter (m) = 1,000 millimeters (mm). Thus, 1 m2 = 1 x 106 mm2. Substitution of square millimeters for square meters results in40 x 106 mm2 ÷ 300 x 106 alveoli = 0.133 mm2/alveolus.
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Clarify Question What is the key concept addressed by the question? • This question is asking you to calculate the surface area of an alveolus. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break alveoli and surface area into their component pieces to understand how they function. Gather Content What do you already know about alveoli? What other information is related to the question? • Alveoli are small sacs within the lungs that are surrounded by capillaries. • Alveoli are surrounded by capillaries, and provide the surface area over which gas exchange occurs. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • If the total surface area is 40 m2, and the number of alveoli is 300,000,000, the surface area of one alveolus is 40 m2/300,000,00 alveoli, which is 0.000000133 m2/alveolus. • 0.000000133m2 is equal to 0.133 micrometers. Reflect on Process Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between alveoli and lungs, but on your ability to break down, or analyze, surface area. If you got an incorrect answer, did you remember that components of alveoli include their role as small units of function within the lung, or that their surface area is related to the surface area of the lungs? Did you have trouble breaking down the idea of surface area to determine the correct answer? 48) A
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Clarify Question What is the key concept addressed by the question? • The question is asking you to describe, from most superficial to most deep, the layers of the thoracic cavity and lung. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to describe the structure of the lung and the surround chest cavity. Gather Content What do you already know about the lungs? What other information is related to the question? • The intercostal muscles are found in association with the ribcage. • Parietal refers to membrane that lines a cavity. • Lungs sit within the pleural cavity. • Visceral membrane is membrane that directly covers an organ. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • A surgeon would first have to cut through the skin. • Recall that the lungs are protected by the ribs, so the intercostal muscles, would be the next layer that would be encountered. • The lungs are housed in the pleural cavity, and the outer boundary of that cavity is the parietal pleural membrane. • The inner layer of the pleural cavity, which is also the layer that touches the lung, is the visceral pleural membrane. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the anatomy of the lungs and the surrounding area in a new situation. If you got an incorrect answer, did you remember that the lungs are surround by the ribcage and intercostal muscles, or that the pleural cavity has parietal pleura as its outer boundary and visceral pleural as its inner membrane? Did you have trouble extending the anatomical features of the lungs and their surrounding tissue to determine the correct answer? 49) B 50) C 51) A
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Clarify Question What is the key concept addressed by the question? • This question is asking about the environmental influence on the release of oxygen by hemoglobin. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to hemoglobin and its tendency to release oxygen. Gather Content What do you already know about oxygen levels? What other information is related to the question? • Diffusion is the movement of a substance from high to low concentration. • As the difference between high and low concentration increases, the rate of diffusion increases. • When blood leaves the alveoli, the PO2 is 100mmHg. • ThePO2 of the tissues of the body is 40mmHg. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since 40mmHg is the lowest value, it creates the largest concentration gradient, which would facilitate the greatest movement of oxygen. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the nature of hemoglobin in a new situation. If you got an incorrect answer, did you remember that the PO2 of blood leaving the alveoli is 100mmHg, or that typical cells have a PO2 of 40mmHg? Did you have trouble extending the nature of hemoglobin to determine the correct answer? 52) C 53) E 54) B 55) B 56) B 57) A
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Chapter 48 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) Animals with closed circulatory systems are more successful than animals with open circulatory systems. ⊚ ⊚
true false
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 2) Why is an open circulatory system less efficient than a closed circulatory system? A) It is moredifficult to quickly deliver O2 to specifictissues when needed with an open circulatory system. B) There is no heartto pump the blood in an open circulatory system. C) Open circulatory systems lack respiratory pigments that bind to oxygen. D) Metabolic wastescannot be removed from tissues in an open circulatory system. E) Blood cannot be used to transportnutrients in an open circulatory system.
3) In 2012, Lance Armstrong was stripped of his record-setting, seven Tour de France titles and banned for life from competitive cycling because of his alleged use of performanceenhancing drugs (PEDs). One of the PEDs Armstrong was accused of taking is erythropoietin (EPO). Why would systematic use of this PED give Armstrong an unfair advantage in a bike race? A) EPO stimulates formation of new capillary beds in skeletal and heart muscle. B) EPO stimulates red blood cell production by the bone marrow. C) EPO stimulates growth of cardiac and skeletal muscle tissue. D) EPO increases cardiac output by stimulating the ventricles to contract more strongly. E) EPO stimulates the synthesis of myoglobin by muscle cells. F) EPO stimulates the formation of new alveoli in the lungs.
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4) The graph below can be used to understand the forces underlying the movement of fluid between the blood and the interstitial fluid. What is a true statement concerning these processes?
A) Sodium ions contribute significantly to the movement of fluid in regionB. B) In people suffering from severe liver disease or protein starvation, thefluid flow in region B is increased. C) Edema results from reduction of fluid flow in region A. D) Fluid leaves theblood in region A and returns to the blood in region B. E) Normally, the net amount of fluid flowin region A is less than the net amount of fluid flow in region B.
5) The liquid portion of blood that contains metabolites, wastes, hormones, ions, and a variety of proteins is called the _______________. A) eosinophil B) lymph C) edema D) plasma E) platelet
6)
Leukocytes (white blood cells) account for about _______ of the cells in human blood.
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A) 0.1% B) 1% C) 10% D) 60%
7) Blood is pumped from the heart into the arterial system, which branches from arteries into fine _________. A) arterioles B) venules C) capillaries D) veins
8) As compared to the circulatory system of most fishes, the circulatory system of adult amphibians has the advantage of A) a four-chambered heart. B) a single circuit. C) partially-separate circuits for gas exchange and systemic delivery of blood. D) a pocket of the gut that serves as an air bladder. E) complete separation between oxygenated and deoxygenated blood.
9)
The benefit provided by all hearts with two atria is A) complete separation of oxygenated and deoxygenated blood. B) that blood is pumped into body tissues at high pressure. C) there is an extra place to store blood when the animal is at rest. D) not all the blood has to pass through both sides of the heart. E) that there are two muscular regions for pumping blood out of the heart to different
organs.
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10) Mammalian, bird, and crocodile hearts have four chambers with two separate atria and ventricles to ensure _____ different circuits for blood flow. A) two B) three C) four D) eight
11) Joaquin is suffering from congestive heart failure, in which blood flow is backed up in his lungs and excess fluid is escaping the blood and accumulating in his lung tissue. If untreated, increasing pulmonary edema will lead to death by suffocation. What is the most-likely cause of Joaquin’s congestive heart failure? A) Contraction of his right atrium is not keeping up with contraction of his left atrium. B) Joaquin’s pulmonary semilunar valve is not opening properly. C) Joaquin’s right atrioventricular valve (tricuspid valve) is not closing properly. D) Joaquin’s SA node is malfunctioning. E) Contraction of his left ventricle is not keeping up with contraction of his right ventricle.
12) A higher protein concentration within the distal portion of capillaries draws water into them through the process of A) active transport. B) facilitated diffusion. C) diffusion. D) filtration. E) osmosis.
13) In birds and mammals, a vestige of the sinus venosus of the fish heart remains as the sinoatrial node, which serves as a(n)
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A) diastoledetector. B) baroreceptor. C) site oferythropoiesis. D) inhibitorynode. E) pacemaker.
14)
What would be the physiological effect of an increase in the venous return to the heart? A) decreased cardiacoutput B) increasedsecretion of ADH (vasopressin) C) increased strokevolume D) decreasedsecretion of atrial natriuretic hormone E) increasedsympathetic stimulation of the heart
15) Changes in the arterial blood pressure are detected by __________ located in the walls of the carotid artery and the arch of the aorta. A) baroreceptors B) pacemakers C) Purkinjefibers D) bundlebranches E) osmoreceptors
16)
All of the following are functions of the circulatory system EXCEPT A) oxygen, nutrient, and waste transport. B) creation of redand white blood cells. C) blood clotting and immune defense. D) temperature regulation. E) hormone transport.
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17) A bone marrow sample from Patient X has abnormally-low numbers of megakaryocytes. What body process would you expect to be impaired in Patient X? A) transport of oxygen B) defense against foreign microorganisms C) blood clotting following injury to a blood vessel D) temperature regulation by vasoconstriction or vasodilation of superficial blood vessels E) maintaining normal osmotic balance between the blood and the interstitial fluids
18)
Which of the following solutes is NOT normally found in the plasma? A) metabolites, wastes, and hormones B) ions C) albumin D) hemoglobin E) globulins
19)
Which blood cell type is correctly matched to its function? A) platelets—hematopoiesis B) leukocytes—bloodclotting C) erythrocytes—immunity D) leukocytes—oxygentransport E) monocytes—defenseagainst microorganisms
20) You are taking a lab practical exam. One station has a microscope slide of a cross section through an artery and vein. Which vessel is the artery?
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A) the vessel with the wider lumen (e.g., interior space that contains the blood) B) the vessel with more muscle tissue and elastic fibers in its wall C) the vessel lined only with endothelium D) the vessel with valves to prevent backflow E) the vessel with a greater overall diameter
21)
Exchange of gases and metabolites between the blood and tissues occurs in the A) arteries. B) arterioles. C) capillaries. D) venules. E) veins.
22) When you are upright, what is the primary mechanism that propels blood in your feet back to your inferior vena cava? A) the valves in theleg veins alternating between open and closed B) contraction ofsmooth muscle in the walls of the leg veins C) recoil of elasticfibers in the walls of the leg veins D) contraction of theleft ventricle of the heart E) contraction ofskeletal muscles in your legs
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23)
Refer to the diagram shown here of the mammalian circulatory system.
If blood is going from the lungs to space 3, what is the name of space 3? A) left ventricle B) left atrium C) right ventricle D) right atrium E) pulmonary vein F) aorta
24) Elephantiasis is an infectious disease in which blockage of the circulatory system by microscopic, parasitic roundworms results in a dramatic swelling of the tissues in the lower half of the body. What region is most likely blocked by these small, thread-like worms? A) the left atrium of the heart B) a pulmonary artery C) lymphatic vessels and/or lymph nodes D) a carotid artery E) the superior venacava
25)
What is true about the lymphatic system?
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A) Fluid movesthrough the lymphatic system under high pressure. B) It collects fluidthat seeps into the tissues and returns it to the blood. C) It is bidirectional. D) It exhibits peristaltic contractions. E) It carries allabsorbed materials from the stomach and intestines to the liver.
26)
The cells that normally lack a nucleus and have a relatively short life span in humans are A) neutrophils. B) eosinophils. C) basophils. D) erythrocytes. E) lymphocytes.
27) Under what circumstance would your body experience an increase in erythropoietin secretion? A) if you just moved from New York City to start training for a marathon in the 'MileHigh' city of Denver, Colorado B) if your hematocrit is elevated above normal levels C) if you are suffering from dehydration D) after drinking 5 liters of water in just 2 hours E) if you are suffering from hypertension
28) What class of sensory receptorsdirectly affects the activity of the cardiac center in the medulla oblongata? A) sensory cells inthe juxtaglomerular apparati of the kidneys B) osmoreceptors inthe hypothalamus C) baroreceptors inthe arch of the aorta and in the carotid arteries D) blood pHchemoreceptors in the aortic and carotid bodies E) blood glucosesensors in the pancreas
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29)
Scientists believe that the heart of the common (chordate) ancestor of all vertebrates A) was little morethan a heavily-muscled region of the ventral artery. B) had twochambers. C) had threechambers. D) had fourchambers. E) consisted of asingle ventricle.
30) When submerged, frogs receive most of their O2 from capillaries within the skin. What structure would contain blood with the highest O2 concentration in a submerged frog, which is not able to breathe using its lungs? A) left atrium B) right atrium C) aorta D) ventricle E) pulmonary vein
31)
The left ventricle in mammals is more muscular than the right ventricle because
A) the right ventricle only pumps blood into the right atrium. B) the left ventricle pumps more total blood than the right ventricle. C) the left ventricle pumps blood with a higher hematocrit than the blood that leaves the right ventricle. D) the left ventricle has to pump blood throughout the body at high pressure. E) the left ventricle is always contracting to maintain a systemic blood pressure.
32)
What would happen if your SA node and AV node fired at same time?
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A) The QRS wave on an ECG would disappear, as it would be masked by the P wave. B) Your stroke volume would decrease. C) Blood would be forced back into the atria from the ventricles. D) Your blood pressure would increase. E) The production of nitric oxide by your endothelial cells would increase.
33)
Refer to the diagram below.
What is the correct order of structures in the electrical excitation pathway that generates a normal heartbeat? A) 1, 2, 3, 4, 5,6 B) 1, 5, 4, 2, 3, 6 C) 6, 3, 2, 4, 5,1 D) 3, 6, 2, 4, 1, 5 E) 3, 2, 6, 4, 5,1 F) 2, 5, 1, 4, 6, 3
34)
The blood pressure in your brachial artery is at its lowest during
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A) exercise. B) the time the aortais maximally stretched. C) the systolic period. D) the diastolic period. E) ventricular contraction.
35) Which secreted molecule is LEAST likely to effect a significant change in blood pressure? A) antidiuretic hormone B) aldosterone C) atrial natriuretic hormone D) high-densitylipoprotein E) nitric oxide
36)
What animal group is mismatched with its circulation system type (open or closed)? A) oyster—open B) cricket—closed C) earthworm—closed D) lobster—open E) killer whale—closed
37)
What is true about about mammalian red blood cells? A) Red blood cells are also called leukocytes. B) A mature redblood cell is shaped like a biconcave disc because it has nonucleus. C) Red blood cellscontain albumin. D) Red blood cellsdevelop from lymphoid stem cells. E) Aged red bloodcells are removed from the blood by the kidneys.
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38) In the blood clotting cascade mechanism, which specific enzyme catalyzes the conversion of fibrinogen to fibrin? A) albumin B) renin C) catalase D) angiotensin E) thrombin
39)
One mechanism that some animals use to limit heat loss in cold environments is A) vasodilation of the near surface blood vessels. B) vasodilation of below surface blood vessels. C) vasoconstriction of the precapillary sphincters in the skin. D) vasoconstriction of veins. E) increasing cardiac output.
40) Edema is a result of increased interstitial fluid in various tissues of the body. All of the following are causes of edema EXCEPT A) pregnancy. B) liver disease. C) injury to a limb. D) protein malnutrition. E) abnormally lowblood pressure.
41)
The greatest metabolic advantage of a fish's two-chambered heart is
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A) its ability topump blood under high pressure to all areas of the fish's body. B) its ability topump blood to the gills for gas exchange before the blood is pumped to theremaining areas of the body. C) its ability to stay full of blood even as it is emptying into the conus arteriosus. D) its ability tokeep oxygen-rich blood in one chamber separate from oxygen-poor blood inthe other chamber. E) its ability tomaintain a constant blood pressure in the fish.
42) When lungs evolved in vertebrates, the evolution of _____ also occurred in the circulation of blood within those vertebrates. A) doublecirculation B) red blood cells C) a lymphaticsystem D) a muscularheart E) more plasma
43)
The depolarization of the heart is initiated by the A) left and rightbundle branches. B) sinoatrial node. C) atrioventricular node. D) Purkinjefibers. E) bundle of HIS.
44) A friend asks you to explain the difference between atherosclerosis and arteriosclerosis. You say, "Well
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A) atherosclerosis is a condition that results from too much calcium being deposited in the arteries, while arteriosclerosis results from the accumulation of cholesterol deposits in the arteries." B) atherosclerosis is a condition that results from having angina pectoris occurring in the arteries of the heart, while arteriosclerosis results from the accumulation of cholesterol deposits in the arteries." C) atherosclerosis is a condition that results from too much calcium being deposited in the arteries, while arteriosclerosis results from having angina pectoris occurring in the arteries of the heart." D) atherosclerosis is a condition that results from the accumulation of cholesterol deposits in the arteries, while arteriosclerosis results from too much calcium being deposited in the arteries." E) atherosclerosis and arteriosclerosis are nearly the same and usually occur after a stroke."
45)
Which animal is likely to have the circulatory pattern shown in the figure?
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A) frog B) crocodile C) bird D) mammal E) fish
46)
What factor most limits a person’s maximal increase in cardiac output during exercise? A) the time available to fill the heart chambers with blood as the heart rate increases B) the time it takes for electrical impulses to reach all parts of the heart C) the rate at which cardiac muscle contracts D) the rate at which oxygen is delivered to the cardiac muscle cells E) the total amount of blood in an individual
47) The loudest sounds a nurse hears while listening to a patient's heart through a stethoscope are caused by A) contraction of theventricles. B) contraction of theatria. C) closing of the AVvalves. D) opening of thesemilunar valves. E) depolarization ofthe ventricles.
48) In a vertebrate with a four-chambered heart, the structure(s) containing blood with the highest O2 concentration is/are the _______________. A) pulmonaryarteries B) pulmonary veins C) right atrium D) inferior vena cava E) rightventricle
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49) A nurse takes your blood pressure during your annual examination, and she enters a reading of 115/70 in your medical chart. These numbers mean that the A) pressure in your brachial artery during ventricular contraction is 115, while the pressure during ventricular relaxation is 70. B) pressure in your brachial artery during ventricular contraction is 115 while the pressure during atrial contraction is 70. C) nurse heard sounds through the stethoscope only when the pressure in your brachial artery was exactly 115 and again when it was exactly 70. D) pressure in the ventricles of the heart is 115 when the ventricles are contracting and 70 when the ventricles are relaxing. E) diastolic pressure is 115 and the systolic pressure is 70.
50)
The P wave of the ECG represents A) the contractionof the atria. B) the relaxation of the atria. C) the depolarization of the atria. D) the repolarization of the atria. E) the contraction of the ventricle.
51)
Stimulating the vagus nerve would cause A) blood pressure to rise. B) bloodvolume to increase. C) heart rate to decrease. D) increased firingof the SA and AV nodes E) a release ofepinephrine.
52)
Myeloid stem cells give rise to all formed elements in the blood EXCEPT
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A) erythrocytes. B) lymphocytes. C) platelets. D) monocytes. E) basophils.
53)
What type of mollusk has a closed circulatory system? A) clam B) slug C) snail D) squid E) scallop
54) You are taking a lab practical exam, and one station has pins in various internal structures of a bisected mammalian heart. You can orient yourself without picking up and examining the exterior of the heart because A) the width of the external wall of the right ventricle is thicker than all the other chamber walls. B) the width of the external wall of the left atrium is thicker than all the other chamber walls. C) the width of the external wall of the left ventricle is thicker than all the other chamber walls. D) the width of the external wall of the right atrium is thicker than all the other chamber walls. E) the ascending aorta exits from the right ventricle.
55) Susie just squished a cockroach and its pale yellow hemolymph squirted out on the floor. If Susie analyzed the hemolymph, she would expect to find all of the following EXCEPT
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A) amino acids. B) sugars. C) erythrocytes. D) water. E) ions. F) cells that protect against foreign microbes.
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Answer Key Test name: Chap 48_13e_Raven 1) FALSE
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Clarify Question What is the key concept addressed by the question? • This question is asking about the relationship between closed circulatory systems the success of a species. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the idea of success as a species. Gather Content What do you already know evolutionary success? What other information is related to the question? • The evolutionary success of a species is related to its current existence, the duration of its history of a species, and the abundance of the species over time. • Open circulatory systems have a beating heart and some blood vessels, but the blood eventually enters an open space in which it bathes the tissue directly. • In a closed circulatory system, the red blood cells do not leave the blood vessels under normal circumstances. • In a closed circulatory system the blood is moved directly to individual tissues, so the efficiency of oxygen delivery is increased. • Since the vascularization in a closed circulatory system is more extensive than that which occurs in an open circulatory system, a closed circulatory system can be considered more complex. Choose Answer Given what you now know, what information is most likely to produce the correct answer? Version 1
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• While the increased efficiency of a closed circulatory system does make larger body size possible, greater body size does not indicate success. • The most numerous animals on our planet today, the insects, have open circulatory systems. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the idea of biological success in a new situation. If you got an incorrect answer, did you remember that success is not necessarily related to complexity, or that animals with open circulatory systems are both abundant and diverse on our planet? Did you have trouble extending the idea of evolutionary success to determine the correct answer? 2) A
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Clarify Question What is the key concept addressed by the question? • This question is asking about the inefficiency of an open circulatory system. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the lack of efficiency of an open circulatory system. Gather Content What do you already know about open circulatory systems? What other information is related to the question? • An open circulatory system consists of a beating heart and blood vessels. • Rather than entering capillaries, blood in an open circulatory system leaves the vessels and bathes the tissues generally. • Blood and the extracellular fluid mix in an open circulatory system, and are together referred to as hemolymph. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Open circulatory systems do have hemolymph that has respiratory pigments, so that answer can be dismissed. • Some of the functions of blood in any circulatory system, including an open system, is to transport nutrients and to remove waste. • A heart is present in an open circulatory system. • A characteristic of an open circulatory system that does lead to inefficiency is that blood cannot be delivered to specific tissues; rather it Version 1
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is delivered to sinuses, where it bathes multiple tissues at once. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the characteristics of an open circulatory system in a new situation. If you got an incorrect answer, did you remember that the hart drives theblood into vessels and then into open sinuses, or that the blood is still used for transport and waste removal in open systems? Did you have trouble extending the features of an open circulatory system to determine the correct answer? 3) B
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Clarify Question What is the key concept addressed by the question? • This question is asking about the function of erythopoietin. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the role of erythropoietin in athletic ability. Gather Content What do you already know about erythropoietin? What other information is related to the question? • Red blood cells are known as erythrocytes. • Erythrocytes carry oxygen to the tissues of the body. • Oxygen is used in the last stage of cellular respiration. • Cellular respiration makes energy available for activity by converting the stored energy in nutrients into a usable form. • A plasma protein is converted into erythropoietin in the kidneys. • Erythropoietin stimulates the red bone marrow to make erythrocytes. • Erythrocytes are made from stem cells. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The only function of erythropoietin is to stimulate the production of new red blood cells. • This would increase the amount of oxygen that can be carried to cells, and would potentially increase cellular respiration and available energy. • Erythropoietin does not act outside of the production of blood, so although the other answers might accelerate oxygen delivery to cells, the Version 1
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only correct response is that erythropoietin stimulates the production of red blood cells. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the function of erythropoietin in a new situation. If you got an incorrect answer, did you remember that erythropoietin stimulates the redbone marrow, or that the red bone marrow produces erythrocytes? Did you have trouble extending the function of erythropoietin to determine the correct answer? 4) D
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Clarify Question What is the key concept addressed by the question? • This question is asking you to interpret a graph that shows the movement of materials in and out of the blood. What type of thinking is required? • Analyze level (sample phrases, or use your own): o This is an analyze question because you have to break pressure and blood flow into their component pieces to understand how they function. Gather Content What do you already know about the movement of materials in and out of the circulatory system? What other information is related to the question? • A solution is made of dissolved particles (solute) and a liquid component (solvent). • Where there is more solute, there proportionally is less solvent. • Osmosis is the movement of a liquid (solvent) from high to low concentration of that liquid. • Osmotic pressure is the tendency of a solution to allow water to flow in water via osmosis. • Osmotic pressure increases as solute concentration increases and solvent concentration decreases. • Through osmosis, fluid leaves the circulatory system near the arteriole ends of capillaries, and returns to the blood near the venular side of capillaries. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • In region A, the osmotic pressure is lower than the blood pressure. Where osmotic pressure is lower, solute concentration is lower, and there is a higher concentration of fluid. Fluid moves from an area of high concentration to low concentration. Therefore, fluid flows out of the arterioles, where fluid concentration is higher, toward the tissues. • In region B, the opposite is true. Osmotic pressure is higher than the blood pressure in the circulatory system, which means there is proportionally less fluid. Fluid flows form high concentration to low concentration, so the net movement would be into the blood. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: Version 1
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o Answering this question correctly depended not only on distinguishing between osmotic pressure and solvent concentration, but on your ability to break down, or analyze, osmosis. If you got an incorrect answer, did you remember that components of osmosis include the movement of fluid from high concentration to low concentration, or that as osmotic pressure increases, fluid concentration decreases? Did you have trouble breaking down the osmotic pressure to determine the correct answer?
5) D 6) B 7) A 8) C 9) B 10) A 11) E
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Clarify Question What is the key concept addressed by the question? • This question is asking about the flow of blood between the lungs and the heart. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the cause of congestive heart failure. Gather Content What do you already know about the path of blood between the heart and the lungs? What other information is related to the question? • Deoxygenated blood returns to the right atrium of the heart. • The right atrium forces blood into the right ventricle. • The right ventricle pumps deoxygenated blood to the lungs, where it can receive oxygen. • Oxygenated blood returns to the left atrium of the heart. • The left atrium pumps blood into the left ventricle. • The left ventricle pumps oxygenated blood to the tissues of the body. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The right side of Joaquin’s heart, including the tricuspid valve, the right ventricle, and the pulmonary semilunar valve are working normally since there is an excess of blood in the lungs. • Since an irregular heartbeat was not noted here, there is not reason to suspect the SA node is not functioning as it should. • Joaquin’s blood flow is backing up in his lungs, which means the heart Version 1
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is not pushing blood to the body fast enough. Since the left ventricle is responsible for this, it may not be functioning as it should in Joaquin’s case. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the path of blood between the heart and lungs in a new situation. If you got an incorrect answer, did you remember that the right side of the heart is responsible for sending blood to the lungs, or that the left side of the heart sends blood to the body once it has returned from the lungs? Did you have trouble extending the normal path of blood to determine the correct answer? 12) E 13) E 14) C
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Clarify Question What is the key concept addressed by the question? • This question is asking you to describe the effect of increased return of blood to the heart. What type of thinking is required? • Apply level (sample phrases, or use your own): o You are being asked to take what you already know and use, or apply, it to the consequences of an increased return load of blood to the heart. Gather Content What do you already know about blood return to the heart? What other information is related to the question? • The right atrium receives deoxygenated blood from the body. • Cardiac output (CO) is the amount of blood pumped by a ventricle in one minute. • CO increases with exercise. • CO = stroke volume (in ml) x beats per minute • Stroke volume is equal to the amount of blood that is moved by one ventricular contraction. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Secretion of atrial natriuretic hormone increases with increased blood volume. • ADH secretion increases when blood volume is low. • Cardiac output is directly proportional to venous return. • As more blood returns to the heart, more blood is available to be moved in each ventricular contraction. This is an increase in stroke Version 1
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volume. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use blood return to the heart in a new situation. If you got an incorrect answer, did you remember that stroke volume is a measure of the blood pumped by a ventricle, or that the blood returning to the heart is directly proportional to stroke volume? Did you have trouble extending blood return to the heart to determine the correct answer? 15) A 16) B 17) C
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Clarify Question What is the key concept addressed by the question? • The question is asking about the consequences of a decreased megakaryocyte count. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the shortage of megakaryocytes. Gather Content What do you already know about megakaryocytes? What other information is related to the question? • Blood cells are produced from stem cells in the red marrow of bones. • Blood cells go through different developmental stages. • A committed cell is a cell that is on a definite, specific developmental path. • Megakaryocytes are committed cells in the bone marrow. • Megakaryocytes give rise to platelets. • Platelets play a vital role in clot formation after injury. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • It is white blood cells, not megakaryocytes that defend the body against foreign invaders. • Red blood cells, not megakaryocytes, transport oxygen. • Temperature regulation and osmotic balance are not functions of megakaryocytes. • Megakaryocytes are large cells that give rise to platelets. Since Version 1
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platelets are required for a blood clot, a low number of megakaryocytes would result in low platelet numbers, which would impair the clotting response. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the function of megakaryocytes in a new situation. If you got an incorrect answer, did you remember that megakaryocytes produce platelets, or that platelets are required for blood clotting? Did you have trouble extending the function of platelets to determine the correct answer? 18) D 19) E 20) B 21) C 22) E 23) B
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Clarify Question What is the key concept addressed by the question? • This question is asking about the path of blood between the heart and the lungs. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the flow of blood between the heart and the lungs. Gather Content What do you already know about CONCEPT X? What other information is related to the question? • Deoxygenated blood returns to the right atrium of the heart. • The right atrium forces blood into the right ventricle. • The right ventricle pumps deoxygenated blood to the lungs, where it can receive oxygen. • Oxygenated blood returns to the left atrium of the heart. • The left atrium pumps blood into the left ventricle. • The left ventricle pumps oxygenated blood to the tissues of the body. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The correct path from the lungs to the heart has blood entering the heart in the left atrium. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Choose from the following samples to streamline your writing: • Apply level: o Answering this question correctly depended on your ability to use the opath of blood between the heart and the lungs in a new situation. If you got an incorrect answer, did you remember that the lungs send blood back to the left atrium? Did you have trouble extending the path of blood between the heart and lungs to determine the correct answer?
24) C
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Clarify Question What is the key concept addressed by the question? • This question is asking you to link a blockage of circulatory vessels to the swelling of tissue. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the impairment of drainage of fluid from tissue. Gather Content What do you already know about the drainage of fluid from tissue? What other information is related to the question? • Most excess fluid that occurs in tissues is absorbed at the venular end of capillaries. • The remaining fluid is picked up by lymphatic capillaries. • Lymphatic capillaries carry the fluid to lymphatic vessels, which carry it to the subclavian veins. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Blockage of the left atrium, carotid artery, superior vena cava, or the pulmonary artery would result in a much more serious situation than just swelling. These structures are major components of the circulatory system. • All of the structures with the exception of the lymph vessels are in the upper part of the body, so blocking them would not result in swelling in the lower part of the body. • Blockage of the lymph vessels would result in retained fluid and Version 1
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swelling. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the removal of excess fluid from the tissues in a new situation. If you got an incorrect answer, did you remember that most fluid is taken back into the circulatory system or that the lymphatic vessels take up the rest? Did you have trouble extending the removal of excess fluid to determine the correct answer? 25) B 26) D 27) A
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Clarify Question What is the key concept addressed by the question? • This question is asking about the function of erythripoietin. What type of thinking is required? • Apply level (sample phrases, or use your own): o You are being asked to take what you already know and use, or apply, it to the need for erythropoietin. Gather Content What do you already know about erythropoietin? What other information is related to the question? • As altitude increases, the oxygen that is available to animals decreases. • Red blood cells are known as erythrocytes. • Erythrocytes carry oxygen to the tissues of the body. • A plasma protein is converted into erythropoietin in the kidneys. • Erythropoietin stimulates the red bone marrow to make erythrocytes. • Erythrocytes are made from stem cells. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The only function of erythropoietin is to stimulate the production of new red blood cells. • This would increase the amount of oxygen that can be carried to cells, which would be important at higher altitudes where oxygen is less available. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the function of erythropoietin in a new situation. If you got an incorrect answer, did you remember that erythropoietin stimulates the redbone marrow, or that the red bone marrow produces erythrocytes? Did you have trouble extending the function of erythropoietin to determine the correct answer? 28) C 29) A 30) B
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Clarify Question What is the key concept addressed by the question? • The question is asking about the location of oxygenated blood in a frog that is not using lungs to breathe. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the location of the highest level of oxygenation in the blood of a frog. Gather Content What do you already know about the path of blood through an amphibian? What other information is related to the question? • The heart of an amphibian has three chambers; two atria and one ventricle. • The right atrium receives deoxygenated blood from the body. • The left atrium receives oxygenated blood from the lungs. • The ventricle pumps deoxygenated blood to the lungs and oxygenated blood to the body. • Frogs can also breathe cutaneously. They take in oxygen and release carbon dioxide through capillaries that are near their thin, permeable skin. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • If oxygen enters the systemic circulation through the skin, it would follow the established systemic circuit. • The only difference in the normal circulatory pattern would have to do Version 1
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with the oxygenation of the blood. Normally when blood returns from the body it has been depleted of oxygen, but if cutaneous breathing occurs, the blood returning to the heart would be oxygenated. • In the systemic circuit, blood returns from the body and enters the right atrium of the heart. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the circulatory pattern of an amphibian in a new situation. If you got an incorrect answer, did you remember that blood return to the right atrium of the heart, or that if the frog is breathing cutaneously, the blood returning to the heart from the body would be oxygenated? Did you have trouble extending the circulatory pattern of a frog to determine the correct answer? 31) D
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Clarify Question What is the key concept addressed by the question? • This question is asking about the asymmetry of the ventricles of a mammalian heart. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the size difference of the right ventricle and left ventricle of a mammalian heart. Gather Content What do you already know about the mammalian heart? What other information is related to the question? • Deoxygenated blood returns to the right atrium of the heart. • The right atrium forces blood into the right ventricle. • The right ventricle pumps deoxygenated blood to the lungs, where it can receive oxygen. • Oxygenated blood returns to the left atrium of the heart. • The left atrium pumps blood into the left ventricle. • The left ventricle pumps oxygenated blood to the tissues of the body. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The force that is required to pump blood to the lungs is much less than the force needed to pump blood to the extremities of the body. • The left ventricle has a much thicker muscle layer because it pumps blood a much greater distance.
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the mammalian heart in a new situation. If you got an incorrect answer, did you remember that the right side of the heart pumps blood to the lungs, or that the left side of the heart pumps blood much further, to the extremities of the body? Did you have trouble extending the mammalian heart to determine the correct answer? 32) B
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Clarify Question What is the key concept addressed by the question? • The question is asking about the effects of firing the SA and AV nodes. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break the musculature of the left and right ventricles into their component pieces to understand how they function. Gather Content What do you already know about the SA and AV nodes? What other information is related to the question? • An electrocardiogram (ECG) records the electrical activity of the heart. • The P wave shows the depolarization/contraction of the atria. • The depolarization/contraction of the ventricles is shown in the QRS wave. The repolarization of the atria is masked by this wave. • The T wave represents the repolarization of the ventricles. • A normal heartbeat requires the flow of an impulse throughout the heart. • The initiation of a heartbeat occurs in the sinoatrial (SA) node located in the right atrium. • The SA node is the pacemaker of the heart. • The SA node initiates the depolarization of the atria. • The action potential from the SA node travels via the internodal pathway to the atrioventricular node. • The impulse travels from the AV node to the bundle branches, and then to the Purkinje fibers where it is dispersed through the ventricles. Version 1
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• To beat efficiently, the atria contract to fill the ventricles. • The ventricles are relaxed as the atria contract, which allows a maximum amount of blood to enter the ventricles. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The P wave is smaller than the QRS wave, so the QRS wave would not be masked. • As long as the atrioventricular valves are working properly, blood will not flow from the ventricle back into the atria. • If the SA and AV nodes fire at the same time, the atria and ventricles would depolarize at the same time. Since the atria normally fill the ventricles by contracting when the ventricles are relaxed, this simultaneous firing of the SA and AV nodes would result in less full ventricles and lower blood pressure. Since less blood would be present in the ventricles, stroke volume would also be lower in this case. • Nitric oxide acts to relax the walls of blood vessels when blood pressure is high, which would not be needed in this situation. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between the actions of the SA and AV nodes, but on your ability to break down, or analyze, the consequences of their simultaneous activity. If you got an incorrect answer, did you remember Version 1
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that components of firing the SA node include the depolarization of the atria, or that the firing of the AV node would likely affect cause blood to leave the ventricles before they were full? Did you have trouble breaking down the actions of the SA and AV nodes to determine the correct answer? 33) D 34) D 35) D 36) B 37) B 38) E 39) C 40) E 41) B
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Clarify Question What is the key concept addressed by the question? • This question is asking about the nature of the heart of a fish. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to determine the metabolic advantage that is conferred by the twochambered heart of a fish. Gather Content What do you already know about the effect of exercise on heart rate? What other information is related to the question? • The ventricle of the fish heart pumps deoxygenated blood to the gills, where it picks up oxygen. • Oxygenated blood moves from the gills through the body. • Oxygen is a required component of aerobic respiration, which occurs in the cells of the body. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The circulatory system of a fish is subject to fluctuating blood pressures in different regions, so the idea of maintaining high pressure is an answer that can be discarded. • Oxygenated and deoxygenated blood are not kept separate by the chambers of the fish heart. • Since the ventricle moves blood to the gills, it becomes oxygen-rich before it moves throughout the body. The high oxygen content allows high metabolism. Version 1
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the circulatory pattern of a fish in a new situation. If you got an incorrect answer, did you remember that the ventricle of a fish heart pumps blood to the gills, or that the gills allow oxygen to move into the blood? Did you have trouble extending the nature of fish blood circulation to determine the correct answer? 42) A 43) B 44) D 45) A 46) A
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Clarify Question What is the key concept addressed by the question? • The question is asking about the greatest limiting factor that impacts cardiac output during exercise. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the limitations of cardiac output. Gather Content What do you already know about the limiting factors on cardiac output? What other information is related to the question? • Cardiac output is equal to the stroke volume multiplied by beats per minute. • Stroke volume is the volume of blood that is moved by a ventricle with one contraction. • With exercise, heart rate increases. • The ventricles receive blood from the atria, which contract to fill relaxed ventricles. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • As heart rate increases, there is less time to fill ventricles. • As ventricles fill less, stroke volume and cardiac output decrease. Reflect on Process Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use cardiac output in a new situation. If you got an incorrect answer, did you remember that cardiac output is directly proportional to stroke volume, or that stroke volume is the volume of blood that is moved by a ventricle? Did you have trouble extending cardiac output to determine the correct answer? 47) C 48) B 49) A 50) C 51) C 52) B 53) D Cephalopods are active predators with large brains to coordinate complex behaviors that require lots of nerve and muscle activity. A closed circulatory system enables them to meet these high metabolic demands. 54) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about the cause of the asymmetry of the heart. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the external appearance of the heart. Gather Content What do you already know about the structure of the mammalian heart? What other information is related to the question? • The heart of a mammal has three layers. • The most variable layer is the middle layer, which composed of muscle. • The heart of a mammal has four chambers. • The upper chambers are the atria. • The atria push blood into the ventricles. • The lower chambers are the ventricles. • The right side of the heart pumps blood to the lungs and back. • The left side of the heart pumps blood to the extremities and back. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since the atria on the left and right side of the heart do the same thing, their size is similar. • The aorta exits from the left ventricle, not the right ventricle. • The left ventricle is much thicker than the right ventricle, which can be seen externally and can be used to identify the sides of the heart. Version 1
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the structure of a mammalian heart in a new situation. If you got an incorrect answer, did you remember that the left side of the heart sends blood to the tissues of the body, or that doing so requires a thicker layer of muscle? Did you have trouble extending the structure of the mammalian heart to determine the correct answer? 55) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about the composition of hemoymph. What type of thinking is required? • Apply level (sample phrases, or use your own): o You are being asked to take what you already know and use, or apply, it to the nature of hemolymph. Gather Content What do you already know about hemolymph? What other information is related to the question? • Hemolymph is a combination of fluid that circulates and extracellular fluid. • Extracellular fluid contains proteins, ions, various macromolecules, and water. • Insects have an open circulatory system that moves hemolymph to sinuses that allow the hemolymph and its contents to directly contact tissue. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Ions, sugar, water, and amino acids are materials that are found in and around cells. They are present in hemolymph. • Insects do have immune cells in their hemolymph. • Insects do not have red blood cells (or respiratory pigments), as they use their tracheal system (and not their open circulatory system) to transport oxygen and carbon dioxide directly to and from cells, respectively. Version 1
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• The absence of respiratory pigments results in the pale yellow color of the hemolymph. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the composition of hemolymph in a new situation. If you got an incorrect answer, did you remember that hemolymph is not used to transport oxygen, or that hemolymph contains the macromolecules that are characteristic of extracellular fluid? Did you have trouble extending hemolymph to determine the correct answer?
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Chapter 49 13e MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 1) Nearly two-thirds of every vertebrate's body is composed of __________. A) water B) carbon C) bones D) muscle
2) The regulatory systems of the animal body maintain a relatively stable internal condition through a process called ____________________. A) homeostasis B) equilibrium C) osmoreception D) countercurrentexchange E) absorption
3) The organ that performs filtration of blood, reabsorption, and secretion in vertebrates is the _______. A) kidney B) liver C) pancreas D) small intestine E) large intestine
4) About 180 liters of blood plasma is filtered into human nephrons per day and, of that amount, about 2-3 liters leaves the body as urine. Therefore, the percentage of plasma filtrate that leaves as urine each day is about _______.
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A) 0.1-0.2 percent B) 0.5-1.0 percent C) 1-2 percent D) 5-10 percent E) 10-20 percent F) 20-50 percent
5) In vertebrates, most of the fluid that ultimately exits the body as urine first enters the nephron tubules by the process of ____________. A) reabsorption B) absorption C) secretion D) filtration E) excretion
6) This molecule or ion never uses active transport as its motive force for reabsorption into blood capillaries in the kidney. A) Na+ ions B) glucose C) amino acids D) water E) HCO3- ions F) Cl- ions
7)
Kidneys are thought to have evolved first among the _____________.
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A) amphibians B) freshwater bony fishes C) saltwater bony fishes D) reptiles E) mammals
8) Marine reptiles eliminate excess NaCl by means of _____________ located near the nose or the eye. A) Malpighiantubules B) antennalglands C) salt glands D) protonephridia E) nephrons
9) In mammalian kidneys, blood in the vasa recta and fluid in the loop of Henle flow in opposite directions to create a ____________ multiplier system. A) homeostatic B) reversible C) countercurrent D) stepped E) exponential
10) Mike has just returned home from college for the summer and notices that his 8-year-old Dalmation dog, Patches, is limping and has difficulty walking up and down stairs. When Mike takes Patches to the vet, the vet recommends that Mike put him on a low-purine diet. This dietary change will lessen the formation of painful precipitates of ___________ in Patches' joints.
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A) adenine andguanine B) ammonia C) uric acid D) urea E) NaCl
11) A doctor suspects his patient has diabetes insipidus. What is the most likely match to the blood and urine profile of this patient?
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A) A B) B C) C D) D
12) Each human kidney contains about a million ______________, which are the tubular functional units of the kidney. A) ureters B) nephrons C) renal medullae D) nephridia E) flame cells
13) Water and small solutes are filtered under pressure out of the blood plasma into nephrons through the porous walls of _________, tufts of capillaries in the renal cortex. A) vasa rectae B) Loops of Henle C) glomeruli D) collectingducts E) juxtaglomerularapparati
14) The presence of a loop of Henle in nephrons is an evolutionary adaptation that enables mammals and birds to reabsorb water efficiently and produce a(n) ____________ urine. A) hypertonic B) hypotonic C) osmolar D) isotonic
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15)
The diffusion of water across a plasma membrane is referred to as A) osmosis. B) active transport. C) facilitated diffusion. D) countercurrent flow. E) bulk flow.
16) Jill is lost in the desert and ran out of water six hours ago. What physiological effect or response would most likely occur in this situation? A) decreased release of ADH from the posterior pituitary B) decrease in blood osmolarity C) increased permeability of the collecting ducts in the kidney D) decreased thirst sensation E) increased release of atrial natriuretic hormone
17) Release of what protein is directly subject to negative feedback inhibition when blood volume rises? A) renin B) aldosterone C) angiotensinII D) angiotensinogen E) atrialnatriuretic hormone
18) You wish to determine which organs function to remove waste products from the hemolymph (blood) of an insect. You do so by injecting a suspension of particulate dye particles into the abdominal cavity of an anesthetized cricket. Where will you find these dye particles 45 minutes later, after you euthanize and dissect the cricket?
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A) in the nephridia B) in the Malpighian tubules C) in the nephrons of the kidneys D) in the protonephridia E) in the antennal glands F) in the urinary bladder
19) You put a solution of sucrose into a bag of dialysis tubing, which is permeable to water but not to sucrose. You then put this bag into a beaker of water. An hour later, you observe that the bag has swelled due to A) active transport of water molecules. B) the osmotic pressure of the sucrose solution. C) the pressure exerted on the bag by the surrounding water. D) passive transport of sucrose molecules. E) the high osmolarity of the surrounding water.
20) All of the following are animal mechanisms to cope with the problem of water balance EXCEPT A) coupling ofwater/salt removal with metabolic waste removal. B) contractile vacuoles. C) passage of waterand waste of the body across a layer of cells into a tubularstructure. D) kidneys used as filtering organs. E) secretion ofregulatory hormones into the tubule.
21) What is true of normal human urine production? I-Blood pressure is used to push nitrogenous waste, water, and small molecules through a filter, forming the filtrate, while cells and most proteins are retained in the blood. II-Most water is reabsorbed as the filtrate is passing through a long tube. III-Ammonia is produced as the metabolic breakdown is excreted.
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A) just I B) just II C) II and III D) I, II, and III E) I and II
22)
One of the key factors in vertebrate colonization of many diverse environments is A) the flexibility provided by selective reabsorption of different solutes. B) not requiring a lot of water due to their closed systems. C) the ability to eat foods with lots of water. D) the ability to control water loss by controlling perspiration. E) the ability to decrease metabolic needs.
23) What is the route a red blood cell would take to circulate through a kidney, starting from the aorta? A) renal artery ->afferent arteriole -> vasa recta -> efferent arteriole ->glomerulus -> renal vein B) renal artery -> glomerulus -> afferent arteriole -> efferent arteriole -> vasa recta -> renal vein C) renal vein ->efferent arteriole -> glomerulus -> afferent arteriole -> vasarecta -> renal artery D) renal artery ->afferent arteriole -> glomerulus -> efferent arteriole -> vasarecta -> renal vein E) renal vein ->vasa recta -> afferent arteriole -> glomerulus -> efferentarteriole -> renal artery F) renal vein ->glomerulus -> efferent arteriole -> afferent arteriole -> vasarecta -> renal artery G) renal artery ->vasa recta -> afferent arteriole -> efferent arteriole ->glomerulus -> renal vein
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24) Claire lost the ability to completely empty her bladder following a stroke, and a nurse inserts a catheter into the open end of her urinary tract each day to remove the urine. Into what structure does the nurse insert the catheter? A) ureter B) bladder C) urethra D) nephron E) collecting duct F) renal pelvis
25)
All of the following are reabsorbed by the nephron EXCEPT A) glucose. B) amino acids. C) water. D) vitamins. E) H+ ions. F) Na+ and Cl- ions.
26) Which solute must be administered in high amounts because of its very efficient secretion and removal by the kidney tubules? A) penicillin B) HCO3- ions C) amino acids D) glucose E) vitamin K
27)
Substances NOT usually found in normal human urine are
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A) urea and uric acid. B) glucosemolecules. C) watermolecules. D) K+, H+, and other ions. E) certaindrugs.
28) The presence of the loop of Henle allows which animals to reabsorb water and produce a hypertonic urine? A) birds B) marine fish C) mammals D) birds and mammals E) freshwater fish and mammals F) birds and reptiles
29) What animal has kidneys that are so efficient that it never has to drink water and can obtain all of its water from its food? A) camel B) gerbil C) kangaroo rat D) pocket mouse E) desert lizard
30) Gary has a kidney stone lodged in his ureter. Where will the radiologist find the kidney stone on an x-ray? A) between the end of a nephron and the renal pelvis B) between the bladder and the outside of the body C) between a kidney and the bladder D) between a Bowman’s capsule and a loop of Henle
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31) How does the loop of Henle enable the mammalian kidney to produce hypertonic urine? I-The ascending limb of the loop actively extrudes Na+. II-The descending limb interacts with the ascending limb to raise the osmolarity of the extracellular fluid in the renal medulla. III-The concentration is further enhanced by the presence of urea, which draws water out of the collecting ducts by osmosis. A) just I B) II and III C) just III D) I and II E) I, II, and III
32) The kidneys are important homeostatic organs, contributing to maintenance of all of the following EXCEPT A) blood volume. B) destruction ofworn-out red blood cells. C) bloodpressure. D) ion concentrationof extracellular fluids. E) blood pH.
33)
What response would correct for a drop in glomerular blood pressure? A) angiotensin II-mediated inhibition of the adrenal cortex B) inhibition of osmoreceptors in the brain, leading to decreased thirst C) dilation of the afferent renal arterioles by angiotensin II D) inhibition of antidiuretic hormone release by the posterior pituitary gland E) stimulation of sodium secretion by the distal convoluted tubules
34)
Where are the receptors that respond to elevated blood osmolarity?
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A) in the adrenalcortex B) in the adrenalmedulla C) in thehypothalamus D) in thekidneys E) in the heart
35)
The adrenal hormone, aldosterone, regulates kidney function by A) reducing theblood flow to the kidney. B) stimulating active reabsorption of sodium, decreasing its excretion. C) increasing the permeability of the collecting duct to urea. D) increasing the permeability of the collecting duct to salt. E) triggering a sensation of thirst.
36)
An increase in the production of ADH affects the kidney tubules by
A) inhibiting reabsorption of sodium ion in the collecting duct. B) decreasing the permeability of the glomerulus to water. C) causing the walls of the collecting duct to become more permeable to water. D) inhibiting the reabsorption of water in the glomerulus. E) decreasing theinsertion of aquaporins into the membranes of cells that linethe collecting ducts.
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37) Roger, who has Type I diabetes mellitus, forgot to take along his insulin on a fishing trip to a remote part of Alaska. It takes him three days to make it out of the wilderness to a hospital. What would be the most likely match to Roger’s blood and urine profile once he reaches the hospital?
A) A B) B C) C D) D
38) Most vertebrates maintain homeostasis in regard to the total solute concentrations of their extracellular fluids and the concentrations of specific inorganic ions. The kidneys participate in regulating the extracellular fluid concentration of all ions below EXCEPT
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A) Fe2+ ions. B) Ca2+ ions. C) K+ ions. D) Na+ ions. E) Cl- ions.
39)
Most marine invertebrates are osmoconformers. This means that
A) that their bodyfluids contain the exact same solutes in the same concentration as theircells. B) the osmolarity oftheir body fluids is the same as their seawater environment. C) that their bodyfluids contain the exact same solutes in the same concentration as theirsurroundings. D) the osmolarity oftheir body fluids is equal to that of the osmoregulators who inhabit the sameenvironments. E) the osmolarity oftheir body fluids fluctuates between hypertonic to hypotonic depending on theseason and the tides.
40)
Select the incorrectly-matched osmoregulatory organ and the organism that uses it. A) nephridia—annelids B) protonephridia—flatworms C) Malpighiantubules—insects D) kidney—fish E) antennal glands—mollusks
41)
Select the incorrectly-matched vertebrate and its urine concentration relative to its blood.
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A) amphibians—isotonic B) marine reptiles—isotonic C) desert mammals—strongly hypertonic D) marine mammals—strongly hypertonic E) terrestrial birds—weakly hypertonic
42) No matter how much water a human drinks, the kidneys are always regulating various aspects of the blood, including _________________. I-the pH of the blood II-the plasma concentration of iron ions III-the plasma concentration of sodium ions IV-the plasma concentration of potassium ions V-the temperature of the blood A) I, II, and III B) I, II, III, and IV C) I, III, and IV D) I, III, IV, and V E) I, II, III, IV, and V
43)
Select the incorrectly-matched organism and its primary nitrogenous waste product. A) most fish—ammonia B) mammals—urea C) reptiles—uric acid D) birds—uric acid E) insects—ammonia
44)
If uric acid accumulates in joints of humans the condition is referred to as
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A) atherosclerosis. B) gout. C) hypertension. D) distalconvoluted tubule dysfunction. E) diabetesinsipidus.
45) Each nephron of the kidney consists of a long tubule and associated small blood vessels. Blood cells and plasma proteins are too large to enter with the glomerular filtrate. What is the correct path for the filtrate to follow through the nephron in the production of urine? A) Bowman's capsule → distal convoluted tubule → loop of Henle → proximal convoluted tubule → collecting duct B) Bowman's capsule→ proximal convoluted tubule → loop of Henle → distal convoluted tubule →collecting duct C) Bowman's capsule → loop of Henle → proximal convoluted tubule → distal convoluted tubule → collecting duct D) Bowman's capsule → collecting duct → proximal convoluted tubule → loop of Henle → distal convoluted tubule E) collecting duct → proximal convoluted tubule → loop of Henle → distal convoluted tubule→ Bowman's capsule
46)
Freshwater fish are _____ with respect to osmoregulation. A) hypotonicregulators B) hypotonicconformers C) hypertonicregulators D) hypertonicconformers E) isotonicconformers
47)
What animals could drink seawater and not get dehydrated?
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A) sea gull B) human C) garter snake D) bullfrog E) freshwaterperch
48)
What animal cannot make hypertonic urine? A) blue jay B) dog C) human D) grasshopper E) American toad
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49) According to the above figure, which letter corresponds to the lowest tubular fluid osmolarity under normal conditions? A) A B) B C) C D) D E) E
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50) According to the above figure, which letter corresponds to the area where water is absolutely not reabsorbed? A) A B) B C) C D) D E) E
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51) According to the above figure, which letter corresponds to the area where amino acids are most likely to be reabsorbed? A) A B) B C) C D) D E) E
52) Connor decides to celebrate his 21st birthday by drinking a few beers at a local sports bar. After a while, Connor notices that he is making many more trips to the men’s room than the week before, when he drank similar amounts of carbonated water. Why is that?
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A) Alcohol stimulatesfiltration of the blood plasma by the glomeruli. B) Alcohol stimulatessecretion of ions into the nephron and water follows by osmosis. C) Alcohol inhibitsreabsorption of sugars, amino acids and other smallmetabolites, which decreases reabsorption of water. D) Alcohol inhibits the secretionof ADH by the posterior pituitary gland, thereby decreasing waterreabsorption. E) Alcohol stimulates theinsertion of aquaporins into the plasma membranes of cells that line thecollecting ducts, thereby decreasing water reabsorption.
53) The kidneys are both protected and held in place by cushions of fat. In cases of rapid weight loss, the kidneys may drop to a lower position, possibly causing kinks in a nearby tubular organ. If this happens, urine will back up into the kidneys, severely damaging them. What organ(s) is/are most-likely kinked in this situation? A) urethra B) ureters C) renalarteries D) nephrons E) renal veins
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Answer Key Test name: Chap 49_13e_Raven 1) A 2) A 3) A 4) C (2-3)/180 x 100 = 1.1-1.67% (or 1-2% rounded down and up, respectively)
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Clarify Question What is the key concept addressed by the question? • This question is asking about the efficiency of the kidneys. What type of thinking is required? • Analyze level: o This question is asking you to identify the percentage of filtrate out of the total blood plasma that is filtered that is released as urine per day. Gather Content What do you already know about filtrate? What other information is related to the question? • Human kidneys produce urine that is much more concentrated than blood plasma. • Concentration of urine occurs in the nephrons as water is reabsorbed. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Solving this question is accomplished by dividing the urine volume that forms by the volume of the blood plasma that is filtered, and multiplying that number by 100 to obtain a percent value. • 2/180 =0.011 (100) = 1.1% Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: Version 1
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o Answering this question correctly depended your ability to recognize that the amount of urine that is formed can be expressed as a percent of the total plasma filtered. If you got an incorrect answer, did you remember that components of the urine formed in this case was 2-3 liters, and the amount of plasma that was filtered was 180 liters? Did you have trouble breaking down the amount of filtrate that becomes urine to determine the correct answer? 5) D 6) D 7) B 8) C 9) C 10) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about the precipitates that can form in the joints of mammals as a result of purine in the diet. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the effects of purine in the diet of a mammal. Gather Content What do you already know about purine? What other information is related to the question? • Mammals produce uric acid as the result of the breakdown of purine. • Humans, other primates, and the Dalmation dog breed lack the enzyme uricase, which transforms uric acid into allantoin. • Since they lack this enzyme, these specific mammals may accumulate uric acid in the joints, which can be painful. • The accumulation of uric acid in the joints is called gout. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since he is a Dalmatian, the painful joints that Patches is experiencing do correspond with the idea of gout. • Gout is the result of the breakdown of purine, a dietary component. • A low-purine diet would lessen the occurrence of uric acid precipitates in the joints. Reflect on Process Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the effects of purine in the diet in a new situation. If you got an incorrect answer, did you remember that purine is broken down into uric acid, and certain mammals lack the enzyme to break uric acid down further, so it may form precipitates in the joints of those mammals? Did you have trouble extending the metabolism of purine to determine the correct answer? 11) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about the diagnostic features of diabetes insipidus. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the characteristics of the bloodwork of someone with diabetes insipidus. Gather Content What do you already know diabetes insipidus? What other information is related to the question? • Diabetes insipidus is the result of the lack of recognized antidiuretic hormone. • Antidiuretic hormone cause water to be reabsorbed during urine formation, so its effect is to concentrate the urine. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • An individual with diabetes insipidus lacks functional antidiuretic hormone. • The only test that shows antidiuretic hormone that is less than a normal level is choice “C”. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the characteristics of someone with diabetes insipidus in a new situation. If you got an incorrect answer, did you remember that diabetes insipidus is caused by the lack of a functional hormone that concentrates the urine, or that the hormone is antidiuretic hormone? Did you have trouble extending the characteristics of diabetes to determine the correct answer?
12) B 13) C 14) A 15) A Version 1
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16) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about the effects of dehydration. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the physiological changes that occur with dehydration. Gather Content What do you already know about dehydration? What other information is related to the question? • The hot, dry conditions of the desert can be very dehydrating in short period of time. • Humans have some water-conserving physiological traits, but they still must consume large amounts of water in very dry climates. • In the kidney, water is reabsorbed in the loop of Henle and in the collecting duct. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Atrial natriuretic hormone causes water to be excreted, so increased presence of this hormone would be dangerous in the desert. • Blood osmolarity is something that must stay in homeostasis. Little deviations are not unusual, but a measureable decrease would not be compatible with life. • The sensation of thirst is an attempt to counteract the effects of dehydration, so decreasing this would not be advantageous in the desert. • Antidiuretic hormone caused the reabsorption of water. Decreasing Version 1
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this hormone would not help dehydration. • Since water can be reabsorbed through aquaporins in the collecting duct, an increase in their permeability would aid water reabsorption and lessen the effects of dehydration. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use dehydration in a new situation. If you got an incorrect answer, did you remember that dehydration is hastened by a hot dry climate, and by lack of water? Did you have trouble extending dehydration to determine the correct answer? 17) A 18) B
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Clarify Question What is the key concept addressed by the question? • This question is asking about the pathway that removes waste from the body of an insect. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the waste removal mechanism of an insect. Gather Content What do you already know about insect physiology? What other information is related to the question? • Insects do not have blood as mammals do; they have hemolymph. • Hemolymph is a combination of circulatory fluid and extracellular fluid. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Insects do not have kidneys, nor do they have nephrons or protonephridia. • Antennal glands are present in some freshwater arthropods, but their function is to excrete excess water. • Insects do not have a bladder, as their nitrogenous waste is excreted through the alimentary canal. • Insects do utilize Malphigan tubules for the secretion of their waste products, so the dye particles should be expected to appear in the Malphigian tubules as they are processed out of the body.
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use waste removal in the insect body in a new situation. If you got an incorrect answer, did you remember that insects lack kidneys, and secrete their wastes into Malphigian tubules? Did you have trouble extending insect physiology to determine the correct answer? 19) B
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Clarify Question What is the key concept addressed by the question? • This question is asking about the movement of water in an experimental setting. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the cause of the uptake of water by a model cell. Gather Content What do you already know about the movement of water? What other information is related to the question? • Solvents such as water move from high solvent concentration to low concentration solvent concentration via osmosis. • Concentration differences between two regions, often across a membrane, are driven by solute concentrations. • As solute concentration increases, osmotic pressure increases, and water concentration decreases. • Solutions move from areas of low osmotic pressure to areas of high osmotic pressure via osmosis. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The dialysis tubing is impermeable to sucrose, so those molecules cannot diffuse through the membrane. • If active transport was involved, the water would move in the opposite direction than it would via osmosis, that is, from low water concentration to high water concentration. This would shrink, rather than Version 1
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fill the dialysis tubing. • The surrounding water does not have high osmolarity, as no solute is mentioned. • The osmotic pressure of the sucrose solution would cause the water to move into the dialysis tubing until that osmotic pressure reaches equilibrium with the surrounding solution. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the movement of water in a new situation. If you got an incorrect answer, did you remember that osmosis is the movement of water from high water concentration to low water concentration, or that solute lowers water concentration in a solution? Did you have trouble extending the movement of water to determine the correct answer? 20) E 21) E 22) A 23) D 24) C 25) E 26) A 27) B 28) D 29) C 30) C 31) E Version 1
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32) B 33) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about the response that is necessary to counteract a drop in glomerular blood pressure. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to a needed response when blood pressure drops in the glomerulus. Gather Content What do you already know about glomeruli? What other information is related to the question? • Afferent renal arterioles supply blood to glomeruli. • Glomeruli are groups of capillaries that occur around tubules in nephrons. • Waste absorption occurs in the glomeruli. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The action of antidiuretic hormone occurs after the glomerulus, so even though its inhibition could increase blood pressure, its effects would be muted. • Distal convoluted tubules also occur after the glomerulus, so action here would not be effective. • Secretion of angiotensin II would be the most immediate and effective way to counteract a drop in blood pressure in the glomerulus, as it would act to constrict the afferent renal arterioles and increase blood pressure.
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use glomeruli in a new situation. If you got an incorrect answer, did you remember that glomeruli receive blood from afferent arterioles, or that angiotensin II dilates arterioles, which would bring more blood into the glomeruli? Did you have trouble extending the workings of the glomeruli to determine the correct answer? 34) C 35) B 36) C 37) A
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Clarify Question What is the key concept addressed by the question? • This question is asking about the body chemistry of a person with untreated diabetes mellitus Type I. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break blood chemistry and urine chemistry into their component pieces to understand how they function in a patient with untreated diabetes mellitus Type I. Gather Content What do you already know about diabetes mellitus? What other information is related to the question? • Diabetes mellitus Type I is juvenile-onset diabetes, although it may be diagnosed at any age. • This condition can result in high blood sugar levels, as insufficient insulin is available to cells. • Insulin stimulates cells to take up blood sugar, thereby keeping blood sugar levels in a homeostatic range. • When blood sugar levels are high, excess blood sugar can be excreted with the urine. • As a solute, the presence of sugar in the urine increases the volume of urine, as more water moves into the urine through osmosis. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • All of the patients in this question have abnormally high blood glucose levels, so this cannot be used as a deciding factor. • Only one patient, shown in choice A, has abnormally high urine volume. This is consistent with someone who has untreated diabetes mellitus. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between urine composition and blood composition, but on your ability to break down, or analyze, the effects of diabetes mellitus Type I. If you got an incorrect answer, did you remember that components of Version 1
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individuals with this condition have insufficient insulin, or that this increases blood sugar levels as well as urine sugar levels and urine volume? Did you have trouble breaking down the effects of diabetes mellitus to determine the correct answer?
38) A 39) B 40) E 41) A 42) C 43) E 44) B 45) B 46) C 47) A
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Clarify Question What is the key concept addressed by the question? • This question is asking about an animal that is able to become hydrated from sea water. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the ingestion of seawater by different vertebrates. Gather Content What do you already know about the use of seawater? What other information is related to the question? • Sea water is hypertonic, or saltier, than the body fluids of most organisms that live in a marine environment. • Drinking sea water is dehydrating unless a mechanism is present to rid the body of excess salt. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • While marine fish are able to excrete excess ions, fresh water fish do not face the issue of excess ions in their environment, in fact they face the opposite issue. Fresh water fish must be able to retain electrolytes. • The bullfrog has a kidney that is the same as a freshwater fish, so they too actively conserve electrolytes. • The sea gull, as a marine bird, is the only creature listed that can excrete excess salt. Marine birds excrete salt through glands near their eyes.
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the elimination of excess salt in a new situation. If you got an incorrect answer, did you remember that freshwater creatures have adapted to conserve electrolytes rather than eliminate them, or that marine birds can drink sea water because they can eliminate the excess ions? Did you have trouble extending the elimination of excess salt to determine the correct answer? 48) E 49) D
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Clarify Question What is the key concept addressed by the question? • This question is asking where osmolarity is lowest in a nephron. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the osmolarity of fluid in different regions of the nephron. Gather Content What do you already know about osmolarity? What other information is related to the question? • Osmolarity is the solute concentration of a solution. • Osmolarity changes as fluid moves through the kidney. • Solutes are reabsorbed from fluid in the kidney in the loop of Henle. • Water is reabsorbed in the loop of Henle and in the collecting duct. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Sections A, B, and C in the diagram show the nephron structure before and in the loop of Henle. • Since solutes are still present at higher concentrations in before and as fluid moves through the loop of Henle, osmolarity is relatively high here. • Section D is a region where osmolarity would be lowest, as solutes have been removed, but not all water has been reabsorbed yet. • Section E, the collecting duct, would have increased osmolarity due to the reabsorption of water in this region. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the changes that occur in tubular fluid in a new situation. If you got an incorrect answer, did you remember that solutes are reabsorbed in the loop of Henle, or that water is reabsorbed in the loop of Henle and also in the collecting duct? Did you have trouble extending the nature of the tubular fluid to determine the Version 1
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correct answer?
50) C 51) A 52) D
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Clarify Question What is the key concept addressed by the question? • This question is asking about the effects of alcohol on urinary output. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the effects of alcohol on urine volume. Gather Content What do you already know about the production of urine? What other information is related to the question? • Antidiuretic hormone normally causes the reabsorption of water, which concentrates the urine and prevents dehydration. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Increasing the number of aquaporins in the collecting ducts would increase water reabsorption and lessen the volume of urine. • Alcohol does not directly influence ion secretion, absorption of metabolites, or glomerular filtration. • Since antidiuretic hormone is inhibited by the use of alcohol, the consequences of ingestion of alcohol include lack of water reabsorption and excessive urination. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use reabsorption of water during urine production in a new situation. If you got an incorrect answer, did you remember that antidiuretic hormone cause reabsorption of water, or that alcohol inhibits the action of antidiuretic hormone? Did you have trouble extending the reabsorption of water during urine production to determine the correct answer? 53) B
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Clarify Question What is the key concept addressed by the question? • This question is asking about the tubular structure that carries urine out of the kidneys. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the change in position of a kidney and the resulting aftermath. Gather Content What do you already know about urine flow from the kidney? What other information is related to the question? • When urine is produced in the kidney, it flows out through the renal pelvis. • The renal pelvis opens into the ureter, which carries urine to the bladder. • As the bladder empties, urine is carried through the urethra out of the body. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Renal arteries and veins carry blood to and from the kidney, but do not carry urine. • Nephrons filter blood within the kidney, but do not leave the kidney. • The urethra is a passage that is distal to the bladder. It carries urine out of the body. • Impeded urinary flow from the kidney is most immediately caused by a blockage in the ureter. Version 1
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the anatomy of the urinary tract in a new situation. If you got an incorrect answer, did you remember that the ureter carries urine away from the kidney, or that the renal artery and vein only move blood to and from the kidney? Did you have trouble extending the path of urine flow to determine the correct answer?
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Chapter 50 13e CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 1) What functions can complement proteins perform? (Check all that apply.) A) amplifythe inflammatory response B) attract phagocytesto the site of infection C) bind Fcreceptors D) coat invadingmicrobes E) insert themselvesinto the foreign cell's plasma membrane F) provide immunityin response to immunization G) store"memories" of specific antigens for months or years
2)
Which of the following are part of the inflammatory response? (Check all that apply.) A) Antibodies andinterferons are produced against the antigens. B) Histamine andother chemicals are released, which produce redness, warmth, and
edema. C) Invading agentcauses the release of pyrogens, which produce a fever. D) Neutrophils andmacrophages attack the invading microbes and contribute to the pus.
3)
Which of the following are types of leukocytes? (Check all that apply.) A) B cells B) basophils C) eosinophils D) erythrocytes E) monocytes F) neutrophils G) T cells
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4) Which statements about the complement system of vertebrates are correct? (Check all that apply.) A) The complementsystem is a part of the immune system of vertebrates. B) The complementsystem consists of approximately 30 different proteins that circulate in theplasma. C) If these proteinsencounter the cell wall of a bacteria or fungi they form aggregations andeventually produce a pore that leads to the destruction of the invadingcells. D) Althoughcomplement proteins attack invaders, they are not involved with histaminerelease. E) The complementsystem produces antibodies to bind invading cells.
5) Select the immunoglobin (Ig) classes that is correctly matched to their facts. Check all that apply. A) IgA—found insaliva, tears, the GI tract, and mother's milk B) IgD—serve asreceptors on the surfaces of T cells C) IgE—promotes therelease of histamine from mast cells and basophils, causing allergysymptoms D) IgG—a minor formof immunoglobulin, used only in response to parasitic worms E) IgM—first secreted during primaryresponse, promotes agglutination, activates complement
6)
Which of the following are organs of the immune system? (Check all that apply.) A) red bonemarrow B) spleen C) thymus D) thyroid E) tonsils
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7) Referring to the figure showing helper T cell function, which statements are true? (Check all that apply.)
A) Cytokines areproduced in both diagrams. B) Antigens play arole in both diagrams. C) Naïve cells areinvolved in diagram I. D) The humoralresponse is represented in diagram II.
8)
Which of the following are a class of immunoglobin? (Check all that apply.)
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A) IgA B) IgB C) IgC D) IgD E) IgE F) IgG G) IgM
9) Which of the following statements regarding hypersensitivity are true? (Check all that apply.) A) The acceptance ofself cells is known as immunological tolerance. B) Allergies arecaused by IgG secretion in response to antigens. C) Autoreactive Bcells produce autoantibodies causing inflammation. D) Itchy welts orhives could be called a local anaphylaxis. E) Delayedhypersensitivity is mediated by TH cells andmacrophages.
10) The hospital where you work is having an emergency blood shortage. Select the following blood types that could safely be given to a young female with type AB Rh- blood. A) A Rh- blood B) A Rh+ blood C) AB Rh- blood D) AB Rh+ blood E) B Rh- blood F) B Rh+blood G) O Rh- blood H) O Rh+blood
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11) While innate immunity is ancient and universal amongst animals, the adaptive immune system is generally considered to be unique to the vertebrates. However, some researchers have suggested, with much controversy, that invertebrates may have a form of adaptive immunity as well. What sort of evidence would be required to fully demonstrate such a claim? (Check all that apply.) A) B and T cells B) CD4 receptors C) efficacy ofvaccination D) highly variablemolecules that can bind various antigens E) identified cellsthat are necessary to provide acquired immunity F) immunoglobulinmolecules G) resistance uponsecond exposure to a pathogen H) specificresistance to one strain but not another after exposure I) thymus gland J) Toll-likereceptors
12) You are studying a mouse strain with a mutation in the alpha constant region of the immunoglobulin heavy-chain. To determine the result of this mutation on the animal, what can you assay? (Check all that apply.) A) binding of IgG tocommon blood pathogens B) binding of IgA tocommon mucosal pathogens C) diversity of theIgG variable region D) IgA titer in thegastrointestinal tract E) IgG titer inserum F) IgG titer in thegastrointestinal tract G) susceptibility tocommon respiratory pathogens
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13) Some of the most common autoimmune disorders include those that affect the joints (rheumatoid arthritis, ankylosing spondylitis), muscles (polymyalgia rheumatica), blood vessels (giant cell arteritis), tear and salivary glands (Sjogren's syndrome), or a differing variety of body tissues (systemic lupus erythematosus). What do these various disorders have in common? (Check all that apply.) A) The immune system is attacking the body's own tissues. B) They are caused by bacterial pathogens. C) They are caused by hypersensitivity to allergens like peanuts, gluten, or pollen. D) They are caused by lifestyle choices like smoking. E) They are psychological. F) They are treated by suppressing the immune system. G) They involve failure of immunological tolerance.
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 14) What cells are phagocytes that can also present antigens to TH cells? A) B cells B) macrophages C) plasma cells D) T cells E) monocytes
15)
What are the helper and inducer cells? A) B cells B) macrophages C) plasma cells D) T cells E) monocytes
16)
What are the source of antibody-producing cells?
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A) B cells B) macrophages C) plasma cells D) T cells E) monocytes
17)
What cells are the precursors of macrophages? A) B cells B) macrophages C) plasma cells D) T cells E) monocytes
18)
Which cells produce specific antibodies? A) B cells B) macrophages C) plasma cells D) T cells E) monocytes
19)
What are on the surface of most vertebrate cells, acting as markers of "self"? A) majorhistocompatibility complex proteins B) T-cell receptors C) antigens D) immunoglobulins
20) The surface defenses of the body consist of the ______ and the mucous membranes lining the digestive and respiratory tracts.
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A) bone marrow B) skin C) T cells D) lymphocytes
21) __________ diseases are those abnormal conditions in which the body's defensive cells fail to make the self versus the nonself distinction correctly, and attack the body's own tissues. A) Septic B) Nondiscrete C) Autoimmune D) Cancerous
22) A patient with melanoma receives three types of therapy: surgery, radiation, and interferon. Which of these represents something the immune system uses against cancer as well? A) Radiation -- a class of lymphocytes uses powerful electromagnetic radiationto attack "altered self" cells. B) Interferon --TH cells and NK cells secrete interferon in response to tumorcells. C) Interferon -- NKcells insert interferon into the membranes of tumor cells, creating large poresthat burst the cells. D) Interferon -- Incomplexes bound with MHC proteins, the interferons indicate the presence ofaltered tissue to B cells.
23)
What category of cells includes both phagocytes and lymphocytes? A) leukocytes B) erythrocytes C) platelets D) target cells
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24)
What molecules are released by activated helper T cells? A) antigens B) immunoglobulins C) cytokines D) antibodies
25) Lymphocyte receptors are encoded by genes that are assembled by rearrangement and mutation of what molecules? A) pre-mRNA B) mRNA C) tRNA D) DNA
26)
What is a necessary component of a powerful immune system? A) immunological tolerance B) stricttemperature homeostasis C) thousands ofdifferent Ig genes D) a large thymusgland
27) The human immunodeficiency virus mounts a direct attack on TH cells by recognizing the _______ surface proteins associated with these cells. A) Fc B) CD4 C) epitope D) cytokine
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28) You sit next to Uncle Ed, an immunologist, at Thanksgiving dinner. "I'm a 'big eater'", he says, "just like the cells I study." What are the large cells that engulf pathogens that Uncle Ed works with? A) monocytes B) erythrocytes C) macrophages D) bacteriophages E) antibodies
29)
What is the name for molecules that provoke a specific immune response? A) antigens B) lymphocytes C) antibodies D) lysozymes
30) In the humoral response, some B cells differentiate into plasma cells. What do plasma cells produce in large quantities? A) agglutinations thatare specific for foreign antibodies B) interferonsspecific for foreign antigens C) immunoglobulinsspecific for foreign antigens D) antigens specificfor foreign antibodies E) macrophagesspecific for foreign antibodies
31) During a blood transfusion, what can occur when the antigens on the blood cells of a blood donor interact with the antibodies that are present in the plasma of a recipient that has a different blood type?
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A) an autoimmunereaction B) an infection C) an agglutinationreaction D) an inflammatoryreaction E) a temperatureresponse
32)
What are two inflammatory mediators secreted by basophils and mast cells? A) immunoglobulinsand antibodies B) antibodies andantigens C) histamines andprostaglandins D) allergens andantigens E) pyrogens andprostaglandins
33)
What is another term for allergy? A) autoimmunity B) antibodies C) hypersensitivity D) antigenshifting E) asthma
34) What is the term for immunity gained by the transfer of antibodies across the placental barrier? A) passiveimmunity B) acquiredimmunity C) humoralimmunity D) cell-mediatedimmunity E) auto immunity
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35)
What initiates the immune response? A) suppressor Tcells B) cytotoxic Tcells C) mediator Tcells D) inducer Tcells E) helper T cells
36)
Where are MHC-II cell surface proteins found? A) macrophages, Bcells, and dendritic cells B) erythrocytes C) acidophils D) neutrophils E) neutrophils andmacrophages
37)
The cell-mediated immune response is brought about by which cells? A) B cells B) T cells C) erythrocytes D) fibroblasts E) lysozymes
38)
What is the blood type of individuals who lack antigens on their red blood cell surfaces? A) A, Rh+ B) B, Rh+ C) AB, RhD) O, Rh-. E) O, Rh+
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39)
Which is the major form of antibody in external secretions? A) IgM B) IgG C) IgD D) IgA E) IgE
40)
With what do cytotoxic cells interact? A) MHC-I proteins B) MHC-II proteins C) foreign antigen D) MHC-I and MHC-IIproteins E) MHC-I proteins and foreign antigens
41)
Which part of an antibody determines to which epitope it will bind? A) the two arms ofthe Y B) disulfide chains C) the heavy chains D) the stem of the Y E) the Fc portion
42)
Which process allows a vertebrate to generate millions of different lymphocytes? A) DNArearrangement B) DNAreestablishment C) clonalvariability D) instructionalvariation E) gene cloning
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43) Which mechanism allows certain viral pathogens to evade the vertebrate immune system? A) becoming asymbiont B) becomingnonvirulent C) frequent changingof surface antigens D) becomingmetabolically inactive E) becoming aspore
44) Which is a treatment for autoimmune disease? I-administration of corticosteroids II-administration of nonsteroidal anti-inflammatory drugs III-aspirin A) I only B) II only C) II and III D) I and II E) I, II, and III
45) When a "new" antigen first challenges the immune system, if the primary immune response produces B cells, what are the fates of those B cells? I-Some of the B cells become plasma cells that secrete antibodies. II-Some of the B cells become memory cells and can produce a swifter response if the body encounters that particular antigen again. III-Some of the B cells secrete chemicals called pyrogens that travel to the brain inducing a fever. A) just II B) just I C) II and III D) I and II E) I, II, and III
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46) When a person is tested for HIV, the test is considered positive if _______ to the HIV are present. A) bacteria B) antigens C) antibodies D) T-cells E) natural killer cells
47)
Select the correct statement regarding the temperature response of the immune system.
A) When macrophagesencounter invading cells, they release immunoglobulin-1, which is carried tothe brain by the circulatory system. B) Interleukin-1 is a pyrogen, which can cause the neurons in the hypothalamus to raise the body's temperature, producing a fever. C) Fever contributesto the body's defenses by stimulating hyperhidrosis and causing the liver andspleen to store magnesium. D) Fevers above 99° Fare often fatal.
48) A friend tells you the following story. "My aunt just received a heart transplant. Her doctors warned us that her body might reject the tissue. I just can't understand how that could happen as human hearts are made of the same tissues, aren't they?" How do you respond?
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A) "Yes, all human hearts are made of cardiac muscles." B) "Yes, all human hearts are made of cardiac muscles, except some humans have different tissues inside their hearts and this could lead to a tissue rejection by the recipient." C) "Yes, all human hearts are made of cardiac muscles. As far as the rejection of tissues goes, your aunt might have different antibodies than did the donor, which could lead to a rejection." D) "Yes, all human hearts are made of cardiac muscles. However, your aunt might have been given some type of drug during the transplant operation that might cause tissue rejection. You can never be too careful in a hospital, you know." E) "Yes, all human hearts are made of cardiac muscles. As far as the rejection issue, everyone has different MHC proteins on their tissues. Your aunt's immune system recognizes the ‘self' tissues but can cause tissue rejection because of the ‘nonself' tissue in her body having different MHC proteins."
49)
Which of the following regarding antigens is true?
A) A large antigen is likely to have many different epitopes, each of which can stimulate a distinct immune response. B) An antigen is a molecule which promotes a general immune response. C) Bacteria do not contain antigens. D) Antigens can onlybe recognized by their lipid moieties. E) The most effective antigens are small simple amino acid complexes.
50)
What do we call a lymphocyte that has never encountered an antigen? A) T cell B) B cell C) foreignlymphocyte D) stem leukocyte E) naïvelymphocyte
51)
Which of the following describes passive immunity?
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A) antibodies transferred to the fetus from the mother across the placenta B) vaccination for polio C) allowing oneself to become infected with chicken pox D) vaccination for influenza E) catching a common cold
52)
Which of the following cells is matched to an incorrect function? A) eosinophil—important to the elimination of parasites B) mast cell—releases histamine C) macrophage—phagocytic cell D) neutrophil—important antigen presenting cell E) monocyte—precursor of macrophage
53)
Which of the following is true regarding cytokines? A) Cytokines are secreted by TH cells and bind to receptors. B) Cytokines are immune cells involved in producing antibodies. C) Cytokines aresecreted by pathogens during infection. D) Cytokines bind to intracellular receptors. E) Cytokines protect in the attack of pathogens by phagocytosis.
54) What is the most fundamental difference between the innate immune system and acquired immune system? A) the way in whichpathogens are recognized B) the way in whichpathogens are destroyed C) the types of cellsthat participate in each response D) the speed
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55) Imagine that a Toll-like receptor (TLR) gene has duplicated and mutated, creating a leucine-rich region binding pocket that can now bind to the hemagglutinin protein in the envelope of influenza virus. What do you predict will happen to this novel gene? A) It will beselected for and over evolutionary time will become an even better receptor forHA protein. B) It will spreadfrom species to species. C) It will undergoVDJ rearrangement. D) It will continue to mutate, perhapschanging to bind other proteins or becoming deleted.
56) Until renamed by Paul Ehrlich in the 1890s, the heat-labile, nonspecific part of the immune system that enhances inflammation was known as "alexin". We now know that various proteins of this system attract neutrophils to tissues, direct phagocytosis of targets by neutrophils and macrophages, burst pathogens by insertion of the membrane attack complex (MAC), stimulate histamine release, and increase capillary permeability. What did Ehrlich rename this part of the immune system? A) complement B) contingent C) toll-like response D) acquiredimmunity E) MBL
57) A patient has come to you for a second opinion. "I have these mysterious lumps in my right armpit," he says, "The other doctor says we may have to remove them. What do you think?" You notice red scratches on the patient's right arm. "You must have a new kitten. Cat scratch disease, from the bacterium Bartonella ," you say, "And we certainly won't remove those lumps, they are really important! Those are your..." A) "thymusglands, where naive B and T cells encounter antigens and becomeactivated." B) "lymph nodes,where T-cell receptor genes are rearranged as T cells mature." C) "lymph nodes,where naive B and T cells encounter antigens and become activated." D) "spleen, where hematopoietic stemcells produce lymphoid and myeloid progenitors."
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58) T cells binding to MHC-peptide complexes are responsible for acceptance or rejection of transplanted organs. To facilitate acceptance of the transplant, the ideal donor will have a close genetic relationship with the recipient -- even then, immune suppression drugs are often necessary. In a strange variation of this phenomenon, the endangered Tasmanian devil of Australia suffers from a devastating disease in which tumorous tissue is transmitted from animal to animal. What is the likely explanation for the lack of rejection of this transmissible tumor? A) MHC genes areunique to humans. Without them, the T cells have no way to distinguish self andnon-self. B) Marsupials lackan adaptive immune system. C) Low genetic diversity makes the MHCgenes invariant, so the "transplanted" tissue is accepted as self. D) Tumors are never targeted by T cells,unless they are caused by a viral infection.
59) You are studying a trafficking protein important for secretion in helper T cells. What is the likely outcome of a defect in this protein? A) impairedsecretion of immunoglobulins B) impairedsecretion of degraded antigens C) impairedsecretion of membrane attack complex D) impaired secretionof cytokines
60) What would happen to immunoglobulin genes if alternative mRNA splicing was nonfunctional? A) Transcripts wouldcontain a single V region only. B) Transcripts wouldcontain all possible V, D, J, and constant regions. C) Transcripts wouldhave extra V, D, and J segments attached to a single constant region. D) Transcripts would have single V and Dsegments, but extra J segments and constant regions.
61) Two proteins, Rag-1 and Rag-2, catalyze VDJ recombination. What is the likely outcome of a deletion of the Rag genes? Version 1
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A) mildsusceptibility to infection due to T cell defects B) increasedantibody diversity from B cells C) severe combinedimmunodeficiency (SCID) of both B and T cells D) increased resistance to infection dueto enhanced B and T cell function
62) Two proteins, Rag-1 and Rag-2, catalyze VDJ recombination. Where would you expect these proteins to be expressed? A) thyroid andparathyroid B) bone marrowonly C) bone marrow andthymus D) thyroid only E) blood serum
63) B cells can generate antibodies with over 1010 different antigen-binding sites. How do so many different antibodies fit onto a single B cell? A) B cells areunusually large cells. B) B cells have wavy,invaginated plasma membranes to provide more surface area. C) B cells have longflagella-like extensions to provide more surface area. D) They don't -- each B cell makes only asingle variety of antibody.
64) A pathogenic virus has a new mutation in one of the coat proteins, that just happens to resemble the structure of a normal human protein present in glial cells of the CNS. What do you predict may be an outcome of infection by this virus? A) The initialresponse to the virus will be strong, but will then be shut down byimmunological tolerance. B) An autoimmunedisease of the brain may develop. C) The innate immunesystem will ignore the pathogen, but the acquired immune system will attackit. D) The membrane attack complex will beunable to burst the viral membrane.
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65) Unless rare antigens are present ideally, a patient needing a transfusion will receive blood of the identical blood type. But in an emergency, what blood type can be given in a transfusion to anyone? A) ABRh-positive B) ABRh-negative C) O Rh-negative D) O Rh-positive E) A Rh-positive
66) When developing a monoclonal antibody-based test kit, great care must be taken to choose an antibody with the right binding properties. Imagine that you are developing a foodtesting kit to specifically detect E. coli 0157:H7, a pathogenic serotype of E. coli that causes food poisoning. Choose the hybridoma line best suited for use in your test kit. hybridoma line
E. coli 0157:H7
E. coli K-12 MG1655
E. coli 0150:H5
E. coli 0152:H28
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A) 1 B) 2 C) 3 D) 4 E) 5
67)
Why must T cell activation take place outside the thymus?
A) An activated Tcell could destroy the other maturing T cells. B) An activated Tcell could then destroy the thymus gland itself. C) Many T cells areself-reactive and must be eliminated in the thymus before any possibility ofactivation. D) Other cell typesmight be accidentally activated in the thymus.
68) In the old days, milkmaids were exposed to cowpox from milking the cows, and this fortuitously gave them some protection from smallpox. What was happening in the milkmaids? A) They werereceiving a dose of generic IgG from the sick cows. B) They wereeffectively receiving a vaccination from a related virus. C) They wereheightening their overall immune response due to exposure to the cowpox andother cow parasites. D) They had astronger immune response from drinking the milk, which sent cow B cellscirculating through their blood.
69) If Peter is allergic to peanuts and Paul is not, what is the precise molecular difference in Peter's bloodstream responsible for this?
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A) Peter's blood hasmast cells and basophils carrying IgEs that match an antigen on peanuts. B) Peter's blood hasa continually excessive level of histamines and prostaglandins. C) Paul's blood hasmast cells and basophils with IgEs that confer immunotolerance to peanuts, butPeter's does not. D) Peter inherited apeanut-specific IgG gene from his mother or father, while Paul did not.
SECTION BREAK. Answer all the part questions. 70) Two kinds of custom antibodies are available -- monoclonal or polyclonal. Polyclonal antibodies respond to a mixture of epitopes from the injected antigenic material; monoclonal antibodies are from a hybridoma strain created from a single B lymphocyte, and thus respond to a single specific epitope.
70.1) You are designing a fast assay system for detecting flu virus in patients. You hope to send these tests to clinics in far-flung regions of the globe so they can conduct surveillance on influenza epidemics. The kits will need to remain functional for several years. What type of antibody will you choose? A) polyclonal B) monoclonal
70.2) Your initial version of the influenza assay kit was a great success. Now you are making a new version that will detect one specific strain of influenza that is particularly virulent, and distinguish it from other typical strains. What type of antibody would be best in this case? A) polyclonal B) monoclonal
71) Different viruses have different properties that affect how the immune system responds to them, and consequently how vaccines must be developed. Version 1
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71.1) Every year a new version of the flu vaccine is made using a mixture of strains. The strains are chosen based on surveillance and analysis by experts from the FDA, WHO, and CDC. For other diseases however, such as varicella (chickenpox), the same vaccine is used continually and repeated vaccinations are not necessary. What do you conclude is the important difference between the influenza virus and the varicella zoster virus with regards to vaccinations? A) Influenza virus istransmitted through aerosol droplets in the air, while varicella can betransmitted via skin secretions. B) Varicella isattacked by the innate immune system, while influenza is attacked by theacquired immune system. C) Influenza virus hasa much higher mutation rate than varicella, leading to frequent antigen changesin the coat proteins. D) Influenza envelope proteins are boundby IgM, while varicella envelope proteins are bound by IgG.
71.2) What is a consequence of the fact that the chickenpox virus has a much lower mutation rate than the influenza virus? A) Chickenpox viruscan "hide out" as latent virus in nerve cell bodies, but influenzacannot. B) Chickenpox createsskin lesions, while influenza leads to body aches. C) Chickenpox viruscan reemerge decades later with the symptoms of shingles, while influenza istransient. D) A chickenpox infection generally givesimmunity against a repeat infection, but people can catch the flu everyyear.
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Answer Key Test name: Chap 50_13e_Raven 1) [A, B, D, E] 2) [B, C, D] 3) [A, B, C, E, F, G] 4) [A, B, C] 5) [A, C, E] 6) [A, B, C, E] 7) [A, B, C] 8) [A, D, E, F, G] 9) [A, C, D, E] 10) [A, C, E, G]
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Clarify Question What is the key concept addressed by the question? • This question is asking about blood type compatibility. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the correct donor blood types for an individual with type AB- blood. Gather Content What do you already know about blood typing? What other information is related to the question? • Blood cells contain markers, or antigens, that are genetically determined. • The names of blood types are references to the antigens that are present. • Type A blood has A antigens. • Type B blood has B antigens. • Type AB blood has both A and B antigens. • Type O blood has neither A nor B antigens. • Rh factor refers to another antigen. • Rh positive blood has the Rh antigen, while Rh negative blood lacks the Rh antigen. • Humans are form with antibodies, or immune defenses, against A or B antigens if their blood type does not include those antigens. • Someone with type A blood is born with type B antibodies. • A person with type B blood has type A antibodies. • When like antigens and antibodies encounter each other, blood clotting occurs. • For instance, if a person with type A blood (who would also have type Version 1
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B antibodies) receives type B blood (that would have type A antibodies) by mistake, a transfusion reaction, or massive clotting, would occur. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • To safely receive blood, a person must not have antibodies against the antigens. • A person with type AB- blood recognizes A and B antigens as self, but would not recognize the Rh antigen. • This person could receive any blood type with A and/or B antigens, and blood type O, as long as the blood that is received is not Rh positive. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the markers on red blood cells in a new situation. If you got an incorrect answer, did you remember that blood type is a reference to which antigens are present, or that antibodies react with antigens to form clots if the wrong type of blood is transfused? Did you have trouble extending blood typing to determine the correct answer? 11) [C, D, E, G, H]
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Clarify Question What is the key concept addressed by the question? • This question is asking about the characteristics of adaptive immunity. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the recognition of adaptive immunity. Gather Content What do you already know about adaptive immunity? What other information is related to the question? • While innate immunity is present at the beginning of life, adaptive immunity requires an exposure to the antigens of a pathogen before a response is mediated. • Adaptive immunity is characterized by the formulation of a very specific response against one specific strain of a pathogen. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • An invertebrate would not need the exact same cells, molecules or organs that vertebrates uses -- if non-homologous parts functioned similarly, we could call it an adaptive immune system. • The formation of antibodies after exposure to an antigen is a classic example of adaptive immunity. • Vaccination works by intentionally exposing an individual to a weakened or dead component of an antigen, which does not cause disease, but allow the immune system to learn the pathogen’s identity and to form antibodies (and immunity) against the pathogen. Version 1
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• Vaccines are specific, so they provoke immunity to one specific strain of an antigen. • With a second exposure to an antigen, symptoms of disease do not occur. • Interestingly, a few experiments have shown resistance upon second exposure in invertebrates, but none have identified cells or molecules, so the jury is still out. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use adaptive immunity in a new situation. If you got an incorrect answer, did you remember that adaptive immunity is stimulated by exposure to an antigen, or that adaptive immunity is specific for one antigen? Did you have trouble extending adaptive immunity to determine the correct answer? 12) [B, D, F, G]
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Clarify Question What is the key concept addressed by the question? • This question is asking about the function of the alpha constant region of the immunoglobulin heavy chain. What type of thinking is required? • Evaluate level: o This question is asking you to weigh and judge, or evaluate, the role of the alpha constant region of the heavy chain of an immunoglobulin. Gather Content What do you already know about the alpha constant region of the heavy chain? What other information is related to the question? • The alpha constant region, when bound to a light chain, gives rise to A antibodies. • A antibodies are the most abundant antibodies in secretions. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • G antibody production is not related to the production of A antibodies. • The results of the described mutation could be assayed by observing the binding of IgA to common mucosal pathogens, and by checking susceptibility to common respiratory pathogens. • Alternatively, an IgA titer in the gastrointestinal tract would also reveal the effect of the mutation. Reflect on Process Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Choose from the following samples to streamline your writing: • Evaluate level: o Answering this question correctly depended on your ability to weigh and judge, or evaluate, a mutation in the alpha constant region of a heavy chain. If you got an incorrect answer, did you remember that the alpha constant region in combination with a light chain gives rise to an A antibody? Did you have trouble weighing the merits of antibody production to determine the correct answer? 13) [A, F, G] 14) B 15) D 16) A 17) E 18) C 19) A 20) B 21) C 22) B
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Clarify Question What is the key concept addressed by the question? • This question is asking you to compare the action of the immune system to the action of chemotherapy. What type of thinking is required? • Analyze level: o This question is asking you to identify key factors that qualify something as a function of the immune system or a function of chemotherapeutic action. Gather Content What do you already know about the actions of the immune system? What other information is related to the question? • Interferons are induced by innate defenses. • Two classes of interferons are known. • Type I interferon is produced when viral infections occur. They signal the infection to neighboring cells. • Type II interferon is produced by T cells and natural killer cells. They protect against infection and cancer. • Type II interferon helps to initiate the cellular response, which includes the stimulation of macrophages. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • As interesting as this sounds, lymphocytes do not possess electromagnetic radiation that can be used against other cells. • Interferon is not inserted into the cell membrane of tumor cells by KN cells, nor does it bind with MHC proteins. Version 1
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• Interferon is secreted by T cells and NK cells in response to the presence of tumor cells. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between the actions of chemotherapeutic agents and the actions of the immune system, but on your ability to break down, or analyze, similar outcomes of the two. If you got an incorrect answer, did you remember that components of chemotherapy include interferon, or that interferon is secreted by T cells and natural killer cells in the immune system? Did you have trouble breaking down the characteristics of chemotherapy and immune function to determine the correct answer? 23) A 24) C 25) D 26) A 27) B 28) C "Macrophage" means "big eater". 29) A 30) C 31) C 32) C 33) C 34) A Version 1
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35) E 36) A 37) B 38) D 39) D 40) E 41) A 42) A 43) C 44) E 45) D 46) C 47) B Macrophages release interleukin-1, not immunoglobulin-1. Fever contributes to the body's defenses by stimulating phagocytosis, not hyperhidrosis (excessive sweating) -- sweating is a response that reduces body temperature. Fever also encourages the liver and spleen to store iron, not magnesium. Fevers above 105° F are often fatal. 48) E
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Clarify Question What is the key concept addressed by the question? • This question is asking about the underlying cause of transplant rejection. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to understand the cause of transplant rejection. Gather Content What do you already know about tissues and transplants? What other information is related to the question? • In vertebrates, 4 tissue types give rise to all structures in the body. These are the epithelial, muscle tissue, connective tissue, and nervous tissue. • Tissues are arranged into organs. • An organ in one person is made of the same type of tissue in another person. For instance, heart tissue includes cardiac muscle in all people. • In addition to the foundational tissues that do not differ between people, within a species, there are molecular markers that include species, individual and tissue-level identity. These include MHC markers. • The immune system of one individual recognizes self-markers and does not attack tissue with those markers. • Anything that lack self-markers is attacked by the immune system. Choose Answer Given what you now know, what information is most likely to produce the correct answer? Version 1
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• Although organs are made of the same general tissue types, individual MHC markers differ between individuals. • Transplant rejection is not caused by pharmaceutical ingestion. • If non-self markers are encountered, the immune system attacks the foreign tissue, which causes transplant rejection. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use immune function in a new situation. If you got an incorrect answer, did you remember that tissues have MHC markers on them, or that if the immune system does not recognize the markers, that the tissue is attacked? Did you have trouble extending immune function to determine the correct answer? 49) A 50) E 51) A 52) D 53) A 54) A 55) D
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Clarify Question What is the key concept addressed by the question? • This question is asking about the fate of a Toll-like receptor gene that has mutated. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break TLRs and mutations that occur in them into their component pieces to understand how they function. Gather Content What do you already know about TLRs? What other information is related to the question? • 11 TLRs have been identified in humans. • Human TLRs bind to specific antigen types that are components of pathogens. • Leucine-rich pockets on TLRs allow greater flexibility for binding with pathogens. • Activation of TLRs stimulates innate and adaptive immune responses. • Viruses can evade this response by mutating quickly. • The influenza virus is notorious for the rapid mutation rate of its HA and NA envelope proteins, which usually makes them poor targets for TLRs. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • A mutation within a human species for a TLR would not be spread to another species. Version 1
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• With this mutation, TLRs are able to recognize specific components of the influenza virus. • This recognition would lead to a much faster immune response if the influenza virus is present. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between normal and mutated TLRs, but on your ability to break down, or analyze, the effects of mutation. If you got an incorrect answer, did you remember that TLRs are not usually effective against influenza, or that the leucine-rich pockets that are described would make TLRs much more responsive to influenza? Did you have trouble breaking down the nature of TLRs to determine the correct answer? 56) A 57) C
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Clarify Question What is the key concept addressed by the question? • This question is asking you to identify the nature of inflamed structures in the armpit. What type of thinking is required? • Evaluate level: o This question is asking you to weigh and judge, or evaluate, the presence of lumps in the armpit. Gather Content What do you already know about the composition of tissue in the region of the armpit? What other information is related to the question? • The armpit is one of the regions of the body in which lymph nodes are concentrated. • Lymph nodes become inflamed when infection is present nearby. • Lymph nodes are sites where lymph fluid is filtered. • When pathogens are filtered in lymph nodes, the immune response is perpetuated. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The thymus is located in the chest, so this answer can be excluded immediately. • The spleen is located in the upper left abdominal cavity, under the ribcage, so this answer can also be excluded. • When pathogens are filtered in lymph nodes, B and T cells become activated and the immune response continues. Version 1
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to weight and judge, or evaluate, the presence of a bacterial infection and concurrent swellings in the armpit region. If you got an incorrect answer, did you remember that the armpit is one of the areas in which the lymph nodes are concentrated, or the lymph nodes become inflamed when pathogens are filtered within? Did you have trouble weighing the merits of the immune response to determine the correct answer? 58) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about the cause of the lack of tissue rejection in Tasmanian devils. What type of thinking is required? • Evaluate level: o This question is asking you to compare and contrast human tissue transplants with tissue transplants in Tasmanian devils, making it an evaluate-level question. Gather Content What do you already know about tissue transplants? What other information is related to the question? • In vertebrates, 4 tissue types give rise to all structures in the body. These are the epithelial, muscle tissue, connective tissue, and nervous tissue. • Tissues are arranged into organs. • An organ in one individual is made of the same type of tissue in another individual. For instance, heart tissue includes cardiac muscle in all individuals. • In addition to the foundational tissues that do not differ between individuals, within a species, there are molecular markers that include species, individual and tissue-level identity. • The immune system of one individual recognizes self-markers and does not attack tissue with those markers. • Anything that lack self-markers is attacked by the immune system. • Within small groups of individuals, such as endangered species, genetic variability may be quite low.
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Choose Answer Given what you now know, what information is most likely to produce the correct answer? • If non-self markers are encountered, the immune system attacks the foreign tissue, which causes transplant rejection. • Other organisms have adaptive immunity, especially mammals such as marsupials. • T cells do in fact target tumors, so this answer can be disregarded. • If there is insufficient genetic variability, it is possible that tissue markers do not differ between individuals. This would result in lack of transplant rejection. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to weigh and judge, or evaluate, tissue transplants in abundant versus endangered species. If you got an incorrect answer, did you remember that transplant rejection occurs because of a lack of similarity in tissue markers, or that endangered species may have little genetic variability, including in the genetic variability that leads to different tissue markers? Did you have trouble weighing the merits of tissue markers to determine the correct answer? 59) D 60) D
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Clarify Question What is the key concept addressed by the question? • This question is asking about the consequences to immunoglobulins of alternative splicing of mRNA. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break alternative splicing of mRNA and the nature of immunoglobulins into their component pieces to understand how they function. Gather Content What do you already know about mRNA splicing? What other information is related to the question? • Immunoglobulins, or antibodies, have variable regions that recognize specific antigens, as well as constant regions that are similar for different antibodies. • Many different combinations are possible for the variable regions. • The DNA sequence that codes for the heavy chains of immunoglobulins has approximately 50 V segments, 30 smaller D segments, and 6 smaller J segments. • Each segment codes for a different series of amino acids. • In the synthesis of a heavy chain of an immunoglobulin, a V, D, and J region are randomly selected and joined together. • In the synthesis of immunoglobulins, heavy-chain-encoding premRNA transcripts start at the rearranged VDJ and continue through exons encoding μ and δ constant regions. • Light chains are synthesized in a similar, way except they lack a D segment.
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Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Alternative splicing of tRNA transcripts removes any extra J segments that remain 3′ to the rearranged VDJ, as well as either δ or μ sequences, resulting in transcripts that all encode the same variable region but either μ or δ constant region exons, respectively. • Translation results in a μ or δ heavy-chain polypeptide, which associates with a light-chain polypeptide in the rough endoplasmic reticulum. • Thus, the mature naive B cell expresses both IgM and IgD on its surface, both having the same antigen-binding specificity.. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between the constant and variable regions of an antibody, but on your ability to break down, or analyze, alternative splicing. If you got an incorrect answer, did you remember that components of the variable region include many different possible combinations, or that alternative splicing of mRNA can accommodate this variation? Did you have trouble breaking down the nature of antibodies to determine the correct answer? 61) C
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Clarify Question What is the key concept addressed by the question? • The question is asking about the consequences of the loss of Rag genes. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the effects of the loss of VDJ recombination on immunoglobulin structure and function. Gather Content What do you already know about the VDJ segments? What other information is related to the question? • Immunoglobulins, or antibodies, have variable regions that recognize specific antigens, as well as constant regions that are similar for different antibodies. • Many different combinations are possible for the variable regions. • The DNA sequence that codes for the heavy chains of immunoglobulins has approximately 50 V segments, 30 smaller D segments, and 6 smaller J segments. • Each segment codes for a different series of amino acids. • In the synthesis of a heavy chain of an immunoglobulin, a V, D, and J region are randomly selected and joined together. • VDJ recombination leads to thousands of different heavy chain region sequences. • Light chains are synthesized in a similar, way except they lack a D segment. Choose Answer Version 1
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Given what you now know, what information is most likely to produce the correct answer? • T cells are not the products of antibodies, so they would be unaffected by this deletion. • Antibody diversity would decrease, not increase without these genes, and resistance to infection would decrease as wll. • Since VDJ recombination leads to thousands of different heavy chain region sequences, without the recombination, the heavy chains would be quite similar. • This would result in immunodeficiency due to lack of antibody diversity. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use heavy chain formation in a new situation. If you got an incorrect answer, did you remember that heavy chains have three variable components, or that lack of recombination would lead to fewer matches between antibodies and antigens? Did you have trouble extending heavy chain formation to determine the correct answer? 62) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about the location of antibody production. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the specifics of antibody production. Gather Content What do you already know about antibodies? What other information is related to the question? • VDJ segments are components of antibodies. • Antibodies are proteins that are produced by B cells. • B cells are a subtype of lymphocytes. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The thyroid and parathyroid do not play a role in the production of antibodies. • The blood serum house antibodies, but does not play a role in their production. • Cells that give rise to B cells are found in the bone marrow. • Lymphocytes then migrate to the thymus and other sites to mature. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use antibody production in a new situation. If you got an incorrect answer, did you remember that VDJ segments are components of antibodies, or that antibodies are produced by B cells, which are a type of lymphocytes? Did you have trouble extending antibody production to determine the correct answer? 63) D 64) B
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Clarify Question What is the key concept addressed by the question? • This question is asking about the effects of a viral infection if the virus has coat proteins that are similar to markers of the host. What type of thinking is required? • Evaluate level: o This question is asking you to weight and judge, or evaluate, the effects of a viral infection in which the virus has a coat protein that resembles those of glial cells. Gather Content What do you already know about viral infections? What other information is related to the question? • Viruses are able to infect host cells that have recognizable markers on the cell membrane. • Once inside the host cell, the virus causes the host cell to make copies of the virus, which can spread throughout the host. • Antibodies are the body’s specific response to pathogens, including viruses. • An autoimmune disease occurs when the immune system does not recognize tissue as self, and correspondingly attacks that tissue. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since the coat protein of the virus is similar to that of a cell in the CNS, it stands to reason that an antibody that would defeat the virus could also attack cells of the CNS. • This attack could escalate to an autoimmune disease. Version 1
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• In fact, this type of "molecular mimicry" has been proposed as a mechanism accounting for neurological complications in AIDS patients, since an HIV envelope protein has a 12 amino acid sequence in common with a protein on astrocytes. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to weigh and judge, or evaluate, the immune response to a viral infection. If you got an incorrect answer, did you remember that antibodies are made in response to markers on pathogens, or the criteria to compare a virus and a cell of the body as targets for antibodies includes similarity of markers on both? Did you have trouble weighing the merits of viral infection and immune response to determine the correct answer? 65) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about the blood type that would be unlikely to cause a transfusion reaction. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the safe transfusion of blood based on blood typing. Gather Content What do you already know about blood typing? What other information is related to the question? • Blood cells contain markers, or antigens, that are genetically determined. • The names of blood types are references to the antigens that are present. • Type A blood has A antigens. • Type B blood has B antigens. • Type AB blood has both A and B antigens. • Type O blood has neither A nor B antigens. • Rh factor refers to another antigen. • Rh positive blood has the Rh antigen, while Rh negative blood lacks the Rh antigen. • Humans are form with antibodies, or immune defenses, against A or B antigens if their blood type does not include those antigens. • Someone with type A blood is born with type B antibodies. • A person with type B blood has type A antibodies. • When like antigens and antibodies encounter each other, blood clotting occurs. Version 1
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• For instance, if a person with type A blood (who would also have type B antibodies) receives type B blood (that would have type A antibodies) by mistake, a transfusion reaction, or massive clotting, would occur. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • To safely receive blood, a person must not have antibodies against the antigens. • As long as no rare antigens are present, a person can receive type Oblood in an emergency, since O- blood does not contain A , B, or Rh antigens and would not stimulate an immune response in a recipient since it lacks those antigens. • People with type O- blood are called “universal donors” since they can donate blood to anyone unless rare antigens are present. • Before transfusion occurs, a test called a cross match occurs. This test mixes a few drops of the recipient and donor blood in the lab to be sure no unforeseen reaction occurs. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the markers on red blood cells in a new situation. If you got an incorrect answer, did you remember that blood type is a reference to which antigens are present, or that antibodies react with antigens to form clots if the wrong type of blood is transfused? Did you have trouble extending Version 1
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blood typing to determine the correct answer? 66) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about different hybridoma lines and their use in detecting E.coli 0157:H7 What type of thinking is required? • Evaluate level: o This question is asking you to weight and judge, or evaluate, the best hybridoma line to identify a specific pathogen. Gather Content What do you already know about hybridomas? What other information is related to the question? • A hybridoma is made from the fusion of a lymphocyte and a tumor cell. • Hybridomas are used to produce antibodies. • The best test would indicate the specific pathogen with no ambiguity. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The only hybridoma line that identifies E coli 0:157:H7 specifically, without indicating any other bacterium, is hybridoma 3. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: Version 1
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o Answering this question correctly depended on your ability to weight and judge, or evaluate, various hybridomas. If you got an incorrect answer, did you remember that hybrodoma 3 is the only hybridomas that specifically identifies E.coli 0157:H7 and nothing else? Did you have trouble weighing the merits of the different hybrodomas to determine the correct answer? 67) C Most of the time, the peptides bound to MHC proteins are derived from self-proteins from the individual’s own cells. For this reason, it is important that T cells undergo selection in the thymus so that those that bind too strongly to peptides of self-proteins on self-MHC are eliminated. In this way, T cells normally are activated only outside the primary lymphoid organs in which they mature, when they encounter peptides of foreign proteins on self-MHC—for example, in the case of viral infection or cancer. 68) B Milkmaids who had caught a much milder form of “the pox” called cowpox (presumably from cows) rarely experienced smallpox. Jenner set out to test the idea that cowpox could confer protection against smallpox. He inoculated a healthy child with fluid from a cowpox vesicle and later deliberately infected him with fluid from a smallpox vesicle; as he had predicted, the child did not become ill. (Jenner’s experiment would be considered unethical today.) Subsequently, many people were protected from smallpox by immunization with fluid from cowpox vesicles, a much less risky proposition. We now know that smallpox and cowpox are caused by two different viruses that have similar surfaces. Jenner's patients who were injected with the cowpox virus mounted a defense that was also effective against a later infection of the smallpox virus.
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69) A 70) Section Break 70.1) A
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Clarify Question What is the key concept addressed by the question? • This question is asking about the nature of the influenza virus. What type of thinking is required? • Evaluate level: o This question is asking you to weight and judge, or evaluate, the most efficient way to identify strains of the flu. Gather Content What do you already know about monoclonal and polyclonal antibodies? What other information is related to the question? • An epitope is a portion of an antigen to which to which an antibody attaches. • Monoclonal antibodies respond to one specific epitope. • Polyclonal antibodies can respond to multiple types of epitopes. • The influenza virus is subject to high mutation rates and high rates of genetic recombination. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since influenza virus is notorious for rapid mutation of envelope proteins, the best chance to detect a wide variety of possible viruses would be to develop polyclonal antibodies against a mix of subtypes -- thus responding to multiple antigens. Reflect on Process Did your problem-solving process lead you to the correct Version 1
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answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to weight and judge, or evaluate, monoclonal and polyclonal antibodies. If you got an incorrect answer, did you remember that monoclonal antibodies differ from polyclonal antibodies in that monoclonal antibodies recognize only one specific epitope, or that the influenza virus is constantly changing? Did you have trouble weighing the merits of monoclonal versus polyclonal antibodies to determine the correct answer? 70.2) B
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Clarify Question What is the key concept addressed by the question? • This question is asking about the type of antibody that would be most likely to indicate one specific strain of influenza. What type of thinking is required? • Evaluate level: o This question is asking you to weight and judge, or evaluate, the use of monoclonal versus polyclonal antibodies to detect influenza. Gather Content What do you already know about monoclonal and polyclonal antibodies? What other information is related to the question? • An epitope is a portion of an antigen to which to which an antibody attaches. • Monoclonal antibodies respond to one specific epitope. • Polyclonal antibodies can respond to multiple types of epitopes. • The influenza virus is subject to high mutation rates and high rates of genetic recombination. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The monoclonal antibody is the best choice since it should be highly specific, and would effectively identify one specific strain of influenza. Reflect on Process Did your problem-solving process lead you to the correct Version 1
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answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to weight and judge, or evaluate, monoclonal and polyclonal antibodies. If you got an incorrect answer, did you remember that monoclonal antibodies differ from polyclonal antibodies in that monoclonal antibodies recognize only one specific epitope, or that the question is asking for the identification of one specific type of the influenza virus? Did you have trouble weighing the merits of monoclonal versus polyclonal antibodies to determine the correct answer? 71) Section Break 71.1) C
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Clarify Question What is the key concept addressed by the question? • This question is asking you to differentiate between the influenza and varicella zoster vaccinations. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the reason for different vaccination schedules for different viruses. Gather Content What do you already know about varicella zoster and influenza? What other information is related to the question? • Vaccinations are designed to stimulate antibodies against specific antigens. • If antigens change through mutation, antibodies that were produced by a previous vaccination may not recognize the newly mutated virus. • The mutation rate of varicella zoster is relatively low. • The mutation rate of influenza is high. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Difference is transmission of a virus would not influence the internal efficacy of a vaccine. • Both viruses are attacked by antibodies that are the result of adaptive immunity. • Influenza has a much higher mutation rate, and consequently new Version 1
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vaccines must be developed every year. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use varicella zoster and influenza viruses in a new situation. If you got an incorrect answer, did you remember that influenza mutates reapidly, or that varicella zoster has a much lower mutation rate? Did you have trouble extending the nature of these viruses to determine the correct answer? 71.2) D
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Clarify Question What is the key concept addressed by the question? • This question is asking about the consequences of a lower mutation rate of a virus in terms of vaccination schedule. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the effect of a low mutation rate of a virus. Gather Content What do you already know about viral mutation rates? What other information is related to the question? • Chickenpox is caused by the virus varicella zoster. • Varicella zoster is a virus that has a low mutation rate compared to other viruses. • A vaccine is the intentional injection of epitopes of a pathogen. This will not cause disease, but will stimulate antibody production in the recipient. • The efficacy of antibodies that are stimulated by the receipt of a vaccine relies on the recognition by the antibodies of epitopes on the antigen of the virus. • If a virus does not mutate quickly, its epitopes remain unchanged and can be recognized by the antibodies. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • While chickenpox can become latent for decades and reappear as shingles later, this is not a consequence of the low mutation rate. Version 1
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• Differences in symptoms between influenza and chickenpox are also not a consequence of mutation rate. • Because of influenza's high mutation rate, immunity against last year's version of the virus may not protect against this year's virus. • Chickenpox immunity is much longer-lasting because the virus does not change significantly and can still be recognized by the immune system of the host. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the mutation orate of viruses in a new situation. If you got an incorrect answer, did you remember that mutations can change viruses so they are no longer recognizable by the immune system of the host? Did you have trouble extending the mutation rate of viruses to determine the correct answer?
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Chapter 51 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) Since men produce millions of sperm, but women produce only one oocyte per cycle, in the vast majority of cases infertility is due to a problem with the woman. ⊚ ⊚
true false
CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 2) What are attributes of oral contraceptives? (Check all that apply.) A) They contain aprogesterone and sometimes an estrogen analogue. B) The progesteroneis in the 21-day pills, and the estrogen is in the 7-day pills. C) They help protectagainst ovarian and endometrial cancer. D) They areappropriate for use by smokers over age 35. E) They have a lowfailure rate of only 1 to 5% a year. F) They act by inhibiting LH and FSHsecretion, inhibiting ovulation.
3) If you discovered a new colonial organism living deep on the sea floor, how could you determine whether it reproduced sexually or asexually? (Check all that apply) A) Compare DNA to seeif nearby individuals are identical. B) Compare morphologyto see if nearby individuals are identical. C) Look for externalbuds still attached to the parent. D) Look for acoelom. E) Look for gonadswith mitotic figures and embryos. F) Look for gonads with meiotic figuresand gametes.
4) In the waiting room of a doctor's office, the staff are creating an educational display about varieties of birth control. What general categories of birth control will they want to outline?
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A) drugs that blockgonad development B) devices to preventimplantation C) hormones to closecervix D) hormones toprevent ovulation E) hypothalamic implants F) nasal spray for males G) sperm barriers H) spermdestruction I) surgicalsterilization J) abstinence
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 5) What is the primary means of reproduction among the protists, cnidaria, and tunicates? A) asexualreproduction B) sexualreproduction C) asynchronousreproduction D) hermaphroditicreproduction
6) Terrestrial vertebrates and some fish evolved a form of fertilization in which the male gametes are introduced into the female reproductive tract. What is this called? A) synchronousfertilization B) externalfertilization C) internalfertilization D) asexualfertilization
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7)
Internally fertilized organisms can either be born alive, or emerge from what structures? A) follicles B) ducts C) capsules D) eggs
8) Some internally fertilized eggs develop and hatch outside the mother's body. What is this developmental strategy called? A) oviparity B) placental development C) marsupial development D) vivipary
9)
What was the most important adaptation of the reptiles and birds to life on land? A) the shelledegg B) the amnioticegg C) the externalegg D) the impermeableegg
10) The immotile sperm develop motility in about 18 hours after arriving at the long, coiled tube called the A) vas deferens B) seminiferoustubules C) epididymis D) testis
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11) In females at puberty, what cells begin to secrete the major female sex hormone estradiol? A) oocyte cells B) corpus luteum C) follicle cells D) granulosacells
12)
What kind of oocyte is released from the ovary at ovulation? A) primary B) germinal C) secondary D) ovum
13)
In males, sterilization involves a vasectomy, which removes a portion of what structure? A) vas deferens B) epididymis C) seminiferoustubules D) Sertoli cells
14)
What term describes avoidance of reproduction without giving up sexual intercourse? A) abstinence B) the rhythm method C) asexual reproduction D) contraception
15)
What stimulates ovulation?
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A) Estradiol B) FSH C) LH D) Testosterone E) Progesterone
16)
What stimulates spermatogenesis? A) Estradiol B) FSH C) LH D) Testosterone E) Progesterone
17)
What stimulates secretion of testosterone by Leydig cells? A) Estradiol B) FSH C) LH D) Testosterone E) Progesterone
18)
What stimulates growth of ovarian follicles? A) Estradiol B) FSH C) LH D) Progesterone E) Testosterone
19)
What completes the preparation of the uterus for pregnancy?
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A) FSH B) LH C) Testosterone D) Progesterone E) Prolactin
20)
What initiates the monthly preparation of the uterus for pregnancy? A) Estradiol B) Testosterone C) Progesterone D) Prolactin E) Oxytocin
21)
What are the only mammals that lay eggs? A) monotremes B) placentals C) marsupials D) there are no egg-laying mammals
22)
In humans, which embryonic tissues are "indifferent"? A) the vertebral column B) the brain stem C) the adrenal gland D) the spinal cord E) the gonads
23) What mammals retain their young for a long period of development within the mother's uterus? Version 1
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A) monotremes B) placentals C) marsupials D) no mammals retain their young within the female
24) An adult male produces sperm continuously by meiotic division of cells lining what structure? A) Malpighiantubules B) Fallopiantubules C) seminiferoustubules D) epididymistubules E) vas deferenstubules
25)
What process is absent in mammals with an estrous cycle? A) oogenesis B) homeostasis C) ovulation D) menstruation E) placenta formation
26)
Ovulation occurs by a surge in the secretion of what hormone? A) estrogenhormone B) luteinizinghormone C) folliclestimulation hormone D) progesteronehormone E) hCG hormone
27)
What hormone is tested for in pregnancy tests?
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A) estrogenhormone B) luteinizinghormone C) folliclestimulation hormone D) progesteronehormone E) hCG hormone
28) What caused intense selective pressure for terrestrial vertebrates to evolve internal fertilization? A) The eggs are toosmall for the males to find and fertilize. B) The gametes couldnot be released next to each other, as they would soon dry up. C) There is nomechanism for eggs and sperm to find one another. D) Terrestrialorganisms only produce small quantities of gametes. E) Gametes andzygotes are vulnerable to predators.
29) What is the term for organisms in which internally-fertilized eggs are laid to develop and hatch outside the mother's body? A) placental B) viviparous C) oviparous D) marsupial E) ovoviviparous
30)
Ovoviviparity is found in A) reptiles. B) birds. C) mammals. D) mollies andguppies. E) marsupials.
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31)
Which of the following statements is true of reptiles? A) Eggs undergo external fertilization. B) Sperm are released in the vicinity of the female. C) Eggs have an amnion and a chorion. D) Larvae become adults by metamorphosis. E) Embryonic and fetal development in all species is only by oviparity.
32)
Which is a correct statement about reptile reproduction compared to bird reproduction? A) Birds areoviparous, reptiles are ovoviviparous. B) Both newly hatchedbirds and reptiles require parental care. C) Both exhibitexternal fertilization. D) The eggs of bothbirds and reptiles have protective shells. E) Male or female reptiles reproduce asexually; birds do not.
33)
What describes marsupial embryos? A) They are bornfully developed. B) They are born highly underdeveloped. C) They hatch from aninternal egg. D) They hatch from anexternally laid egg. E) They are nourishedby the placenta.
34)
What describes placental mammalian embryos? A) They are bornimmediately after fertilization. B) They developinside a leathery shell. C) They completedevelopment in a pouch. D) They hatch from aninternal egg. E) They are totallydependent on the mother for complete development.
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35) The scrotum is a sac-like structure outside the abdomen in which the testes are suspended. Why is this structure essential? A) Sperm must becloser to the penis to be ejaculated. B) There is not enoughspace in the abdomen to grow properly. C) Lower temperatureis required for normal development of sperm. D) There is too muchhormonal influence if they remain in the abdomen.
36)
The sperm head encloses a compact nucleus and is capped by a vesicle called what? A) Sertoli cell B) flagellum C) acrosome D) vas deferens E) epididymis
37)
Which is a correct description of hormone action? A) FSH stimulatesLeydig cells in the testes. B) LH stimulatesSertoli cells in the testes. C) Testosterone stimulates corpus luteum. D) GnRH stimulatesthe anterior pituitary gland. E) Testosteroneregulates LH and FSH in a positive feedback loop.
38) Select the correct sequence of events of the human menstrual phase, beginning and ending with the menstrual cycle.
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A) menstrual phase → proliferative phase → ovulation → secretory phase → menstrual phase B) menstrual phase → ovulation → secretory phase → proliferative phase → menstrual phase C) menstrual phase → secretory phase → proliferative phase → ovulation → menstrual phase D) menstrual phase → proliferative phase → secretory phase → ovulation → menstrual phase
39) The uterine lining proliferates during the female cycle and then sloughs off in what process? A) implantation B) fertilization C) menstruation D) ovulation E) placentation
40)
Where does normal fertilization of an egg by a sperm in a human female occur? A) at the ovary uponovulation B) in the uterusafter the egg has implanted C) in the uterusbefore the egg has implanted D) near the cervixbefore the egg leaves the female E) in the Fallopiantube
41)
Select the correct statement regarding the human female reproductive system.
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A) The ovarianfimbria is the functional unit of the ovary. B) The granulosacells secrete testosterone, which triggers menarche. C) The Fallopian tubes transport ova from the ovary to the uterus. D) The cervixcontains corpora cavernosa tissue, which is a type of erectile tissue. E) The uterus is lined with granulosa cells.
42)
Select the correct pair of statements about FSH and LH function.
A) In males, FSHstimulates spermatogenesis and LH stimulates Leydig cells to secretetestosterone. In females, FSH stimulates growth of follicles and LH stimulates ovulation anddevelopment of the corpus luteum. B) In males, FSHstimulates spermatogenesis and LH stimulates Leydig cells to secretetestosterone. In females, FSH stimulates ovulation and development of the corpus luteum andLH stimulates growth of follicles. C) In males, FSHstimulates Leydig cells to secrete testosterone and LH stimulatesspermatogenesis. In females, FSH stimulates growth of follicles and LH stimulates ovulation anddevelopment of the corpus luteum. D) In males, FSHstimulates Leydig cells to secrete testosterone and LH stimulatesspermatogenesis. In females, FSH stimulates ovulation and development of the corpus luteum andLH stimulates growth of follicles.
43)
How do birth control pills prevent fertilization? A) They alter theuterine environment so that sperm cannot survive. B) They preventfollicle development and ovulation. C) The provide hCG,indicating that fertilization has already occurred. D) They inhibitmenstruation. E) They preventimplantation.
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44)
What is the most commonly employed form of birth control in the United States? A) abstinence B) prevention ofovulation by hormonal inhibition C) sperm blockagewith condoms D) sterilization E) prevention ofembryo implantation with IUD
45)
What is an important benefit of using condoms? A) They preventprostate cancer. B) They have a failurerate of only 1%. C) They can helpprevent osteoporosis. D) They help protectagainst STDs.
46) There are numerous fish genera that have individuals that can change their sex during their lifetime. What is this called? A) sequentialhermaphroditism B) sequential sexdetermination C) sequentialparthenogenesis D) sequentialproduction of gametes E) sequentialfertilization
47) Vertebrates that practice internal fertilization employ three strategies for embryonic and fetal development. In one strategy, the female retains the eggs within her body and the young are fully developed when they hatch inside of her. What is this called?
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A) oviparity B) ovoviviparity C) viviparity D) protogyny E) protandry
48) Vertebrates that practice internal fertilization employ three strategies for embryonic and fetal development. In one strategy, the female retains the young which develop and obtain nourishment from the female's blood. What is this called? A) oviparity B) ovoviviparity C) viviparity D) protogyny E) protandry
49) You notice that in your aquarium, previously full of undoubtedly male fish, one is laying eggs. Upon a bit of research, you find out that the species of fish you purchased is a sequential hermaphrodite. Which of the following is true? A) One of the malefish underwent protandry and became a female. B) One of the male fish fertilized its own eggs. C) Since the fish are hermaphrodites, one of the male fish laid eggs and another will likely fertilize them. D) The fish haveparthenogenesis, therefore their eggs do not have to be fertilized to beviable. E) The fish haveprotogyny, which allows the males to lay eggs.
50)
Which of the following determines genetic sex (male or female) in mammals?
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A) the Y chromosome contained in the egg B) the SRY gene on the Y chromosome C) the temperature of the developing fetus D) the genetic makeup of the parents E) the acrosome of the sperm
51) There are exceptions to the general rule that amphibians lay eggs that develop in the water. These exceptions show extreme variation but they do have one thing in common. What is it? A) They all develop in some sort of pouch. B) They all developin desert environments. C) They all developin habitats with adequate humidity. D) They all develop in a camouflaged environment. E) They all develop more slowly than eggs developed in water.
52)
Why did internal fertilization likely evolve? A) To increase thechances of successful fertilization. B) As a response tocopulation. C) Because there wereno safe places to lay eggs. D) As an adaptationto life in a terrestrial environment.
53)
Choose the correct statement regarding estrous and menstrual cycles. A) Animals withestrous cycles are sexually receptive only when they are ovulating. B) Menstrual cycles are longer than estrous cycles. C) Copulation can only occur during ovulation in the menstrual cycle. D) The lining of the uterus is shed during menstruation and estrous. E) Ovulation onlyoccurs in animals with a menstrual cycle.
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54)
Which of the following have young which feed on milk? A) marsupials B) monotremes C) placental mammals D) placental mammalsand marsupials E) placental mammals, marsupials, and monotremes
55)
Which hormone prevents the corpus luteum from degenerating? A) LH B) FSH C) hCG D) progesterone E) estrogen
56)
Even if utilized properly, what is the least effective means of birth control? A) oral contraceptive B) condom C) foam D) IUD E) implant
57) If a mutant organism used mitosis to produce gametes, what would be the result of mating with a wildtype partner? A) Progeny would bequadraploid, and almost certainly nonviable. B) Progeny would betriploid, and almost certainly nonviable. C) Progeny would benormal -- this is a common occurrence in some phyla. D) The resultingprogeny would be identical twins.
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58) You have discovered a new invertebrate species that is slow-moving and widely dispersed. What might you predict about its reproductive system? A) Males are likely to be smaller than females. B) Females are likelyto be smaller than males. C) It is likely touse internal fertilization and brood care. D) It is likely to behermaphroditic.
59) Your friend is an amateur aquarist learning to breed clownfish. She had one successful clutch of eggs, and moved the mother and fry with their anemone to a separate tank leaving only male fish behind. Now, she is surprised to find that a new female fish has appeared in the original tank. What is the most likely explanation for this? A) Some anemonespecies secrete pheromones that control the sex of fish as a way to regulatepredation. Removal of the anemone allowed a new female to develop. B) In urban areas, tap water is polluted with contamination from endocrinedisruptors such as BPA and PCBs. When she removed some of the tank water forthe new tank, she should have replaced it with bottled water. C) Clownfish areprotandrous hermaphrodites that respond to social cues. Removal of the dominantfemale allowed the second-largest fish to transform into a female. D) Clownfishsynchronize their mating based on seasonal cues indicated by salinity. When shereplaced some of the tank water, the lower salinity caused the fish to changeinto a female.
60) Sea turtles are endangered, in part because of human encroachment on the beaches where they lay eggs. You are working with a team to help protect turtle nests and hatchlings from curious beachgoers. Someone suggests putting a fabric dome over each nest to keep people away. What is your response?
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A) "That willhave several benefits, including protecting the nests from rough weather andhurricanes." B) "That wouldcreate a new problem if it blocked the females, since the females sit on thenests to keep them warm." C) "That mightcreate a new problem. Sea turtles use temperature-dependent sex determination,and lowering the temperature of the nest will likely change the sex ratio ofthe hatchlings." D) "That wouldcreate a new problem if it blocked the males. The males have to be able to diginto the nest to fertilize the eggs."
61) Major extinctions of dinosaurs are associated with large meteor impacts, including the final extinction that wiped them out at the Cretaceous-Tertiary boundary. The particulate matter that would have arisen as a result of impact would have entered the atmosphere and had secondary impacts. Some scientists believe that a fundamental difference between mammals and dinosaurs allowed mammals to survive this event, but doomed the dinosaurs. What may have characterized the last generation of dinosaurs as they went extinct? A) Lungs clogged with dust B) Highly skewed sex ratios C) Hormonal disruptions due to contaminated water D) Weak eggshells due to radiation E) Inability to recognize mates due to diminished sunlight
62) Which type of fish is likely to produce the smallest number of progeny from each mating? A) An oviparous species B) An ovoviparous species C) A viviparous species
63) What is often -- but not always -- a feature that accompanies the evolution of internal fertilization?
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A) meiotically-produced oocytes B) synchronizedgamete release in a population C) fusion of egg andsperm within the female D) a maleintromittent organ
64) At a party, one of your friends has just revealed that he and his wife are trying to conceive. What do you advise him to avoid at the party? A) The loud music B) The raw vegetable appetizers C) The hot tub D) The melted cheese fondue
65) What would be the result for a patient if all his spermatogonia went through meiosis and proceeded to develop into spermatids? A) He would producetwice as many sperm and would be protected against infertility from othercauses. B) He would producetwice as many sperm, which would crowd them during later development and leadto morphological defects. C) He would beentirely normal, since this is what usually happens. D) After one round ofsperm production he would no longer be able to produce sperm and would beinfertile.
66) With help from fertility specialists, a woman with very low follicle-stimulating hormone and luteinizing hormone levels finally conceives a son. If her genetic condition is from a dominant allele and is passed on to her son, what is the likely result? A) He may havefertility problems as well. B) He is likely to have more sons than daughters. C) He will be fine,but his daughters will have a 50% chance of fertility problems. D) As a male, hewill neither express nor pass on these genes.
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67) You are doing veterinary research on dog hormones. In your set of blood samples, you have one male dog with abnormally high levels of follicle-stimulating hormone and luteinizing hormone. What do you suspect may be the explanation for this outlier? A) The dog had beenneutered. B) The dog was afemale, not a male. C) The dog had itspituitary gland removed. D) The dog had a hypothalamic problem causing low levels of gonadotropin-releasing hormone (GnRH).
68) In agriculture, male animals are often castrated to modify their behavior and to produce desirable qualities in the meat. What would you predict about hormone levels in castrated male animals? A) Testosterone is high; follicle stimulating hormone (FSH) and luteinixing hormone (LH) are low. B) Testosterone is low; follicle stimulating hormone (FSH) and luteinixing hormone (LH) are high. C) Testosterone is low; follicle stimulating hormone (FSH) and luteinixing hormone (LH) are low. D) Testosterone is high; follicle stimulating hormone (FSH) and luteinixing hormone (LH) are high.
69)
What special feature of the ovum is facilitated by the production of polar bodies? A) large size of thecell B) extra layers ofplasma membrane C) triploidy D) large size of the nucleus
70) What could be the result if somehow two follicles made it to the late tertiary stage and burst from the ovary?
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A) Nothing unusual -- this describes typical ovulation B) Excessively high estrogen levels, causing menstruation C) Permanent infertility D) Twins
71) A 38-year-old woman is going to ovulate in about a week. For how long has the primary oocyte in her Graafian follicle been arrested at prophase I of meiosis? A) About a day B) 1 week C) 3 weeks D) 38 years
72) A patient at a fertility clinic has been diagnosed with “luteal phase defect” (LPD). Her progesterone levels are low and her cycles are short. What step of reproduction are these symptoms disrupting? A) Follicle development B) Ovulation C) Fertilization of the egg D) Implantation
73) An extremely rare occurrence in humans is a multiple pregnancy with the embryos at different stages due to fertilization weeks apart. What mechanism normally prevents this from happening?
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A) The embryo'ssecretion of FSH and LH maintains the corpus luteum, keeping estradiol andprogesterone high until the placenta takes over secretion of thesehormones. B) The embryo'ssecretion of GnRH maintains the corpus luteum, keeping FSH and LH high untilthe placenta takes over secretion of these hormones. C) The embryo'ssecretion of hCG maintains the corpus luteum, keeping estradiol andprogesterone high until the placenta takes over secretion of thesehormones. D) The follicle'ssecretion of polar bodies maintains the fimbriae, keeping estradiol andprogesterone high until the fallopian tube takes over secretion of thesehormones.
74)
What cause of infertility happens to nearly every woman at some point? A) idiopathicinfertility B) pelvic inflammatory disease (PID) C) endometriosis D) luteal phasedefect E) aging
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SECTION BREAK. Answer all the part questions.
75)
75.1)
According to the figure, what is occurring during day 2?
A) ovulation B) release of corpus luteum C) menstruation D) luteal regression E) copulation
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75.2)
According to the figure, what is a likely day of implantation?
A) Day 3 B) Day 27 C) Day 13 D) Day 21 E) Day 7
75.3) According to the figure, what is the only hormone that doesn't peak during ovulation? A) progesterone B) FSH C) LH D) estrogen E) all female reproductive hormones peak at ovulation
76) Choose the letter of the best match from the following: A. birth control pill B. intrauterine device C. diaphragm D. foams and jellies E. vasectomy
76.1)
Sperm blockage.
76.2)
Sperm destruction.
76.3)
Prevention of egg maturation and ovulation.
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76.4)
Surgical intervention.
76.5)
Prevention of embryo implantation.
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Answer Key Test name: Chap 51_13e_Raven 1) FALSE In human couples with infertility, about 40% of the cases can be attributed to the man, about 45% to the woman, and the rest are unexplained. To be fertile, a man needs to produce a massive number of morphologically and genetically normal sperm. 2) [A, C, E, F] 3) [A, C, F]
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Clarify Question What is the key concept addressed by the question? • This question is asking about how offspring produced by asexual reproduction differ from those produced by sexual reproduction. What type of thinking is required? • Analyze level: o This question is asking you to identify key factors that qualify whether something was produced by sexual or asexual reproduction. Gather Content What do you already know about sexual vs asexual reproduction? What other information is related to the question? • Sexual reproduction is characterized by gonads using meiosis to produce gametes. • Offspring produced by sexual reproduction differ from their parents genetically. • Asexual reproduction is characterized by budding or other strategies that produce genetically-identical progeny. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Members of a species do share a common morphology, but this common appearance can be the result of asexual or sexual reproduction. • A coelom is not diagnostic of sexual or asexual reproduction. Version 1
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Coelomates reproduce sexually and asexually, depending on species and environment. • Gametes are produced via meiosis, so mitotic figures would not be diagnostic. • Individuals that are produced by asexual reproduction are alike genetically, so if nearby individuals are identical, one could conclude they were produced asexually. • Budding is a form of asexual reproduction, so the presence of buds indicates asexual reproduction took place. • Gonads with meiotic figures would indicate that sexual reproduction is occurring. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between sexual and asexual reproduction, but on your ability to break down, or analyze, the resulting offspring. If you got an incorrect answer, did you remember that components of asexual reproduction include genetically identical offspring, or that sexual reproduction utilizes gonads to make gametes via meiosis? Did you have trouble breaking down the different reproductive strategies to determine the correct answer? 4) [B, D, G, H, I, J]
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The categories of contraceptive techniques include: sperm barriers, sperm destruction, hormones that prevent ovulation, devices or hormones that prevent implantation, or surgical sterilization. 5) A 6) C 7) D 8) A 9) B 10) C 11) D 12) C 13) A 14) D 15) C 16) B 17) C 18) B 19) D 20) A 21) A 22) E 23) B 24) C 25) D 26) B 27) E 28) B 29) C 30) D 31) C Version 1
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32) D 33) B 34) E 35) C 36) C 37) D 38) A 39) C 40) E 41) C 42) A 43) B 44) C 45) D 46) A 47) B 48) C 49) A
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Clarify Question What is the key concept addressed by the question? • This question is asking about the reproductive strategy that is exhibited by a male fish that reproduces as a female fish later in its life. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the reproductive pattern of a fish. Gather Content What do you already know about different reproductive strategies? What other information is related to the question? • Hermaphroditism refers to the existence of active male and female reproductive organs (testes and ovaries) in the same body. • Sequential hermaphroditism occurs when an individual is able to reproduce as one gender at one point in life, and then can reproduce as another gender at a later point in life. • Protandry is a form a sequential hermaphroditism in which an individual reproduces as a male first, then reproduces as a female later. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • If it was apparent that an individual was male and not female, the individual could not be a hermaphrodite as well. Version 1
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• If only male fish were present, there would be no eggs to fertilize. A female fish must have been present to produce the eggs. • Protogyny refers to a type of sequential hermaphrodite in which the individual reproduces as a female first, then later as male. This is the opposite of what is occurring in this example. This also does not allow a male to lay eggs. • Parthenogenesis does occur in fish, but eggs still must come from a female, and the individuals in this example were male. • The events in this example can only be explained by protoandry. The individuals were initially male, but were later able to reproduce as females. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use reproductive strategies in a new situation. If you got an incorrect answer, did you remember that hermaphroditism can be sequential, or that protandry occurs when the individual reproduces as a male first, then reproduces as a female later? Did you have trouble identifying the different reproductive strategies to determine the correct answer? 50) B 51) A 52) D 53) A 54) E Version 1
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55) C 56) C 57) B
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Clarify Question What is the key concept addressed by the question? • This question is asking about the effects of a mutation in a gamete. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break mutant and wild type gametes into their component pieces to understand how they function. Gather Content What do you already know about gametes? What other information is related to the question? • Ploidy refers to the number of sets of chromosomes. • Haploid cells have one set of chromosomes, diploid cells have two sets of chromosomes, triploid cells have three sets of chromosomes, etc. • Mitosis makes clones of existing cells. A diploid cell gives rise to a diploid clone via mitosis. • The process of gamete formation normally occurs via meiosis. Meiosis yields four haploid cells from one diploid cell. • Usually fertilization combines a haploid egg and a haploid sperm to make a diploid offspring. Choose Answer Given what you now know, what information is most likely to produce the correct answer? Version 1
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• Normally, meiosis produces haploid (n) gametes. When two haploid gametes fuse, the result is a diploid (2n) embryo. • If a gamete arose through mitosis, it would be diploid. Fusion with a normal haploid gamete would produce a triploid cell. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between mitosis and meiosis, but on your ability to break down, or analyze, the nature of the resulting cells. If you got an incorrect answer, did you remember that cells produced via mitosis are diploid, or that cells produced by meiosis are haploid? Did you have trouble breaking down the concept of gametes to determine the correct answer? 58) D
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Clarify Question What is the key concept addressed by the question? • The concept addressed here is the likely reproductive pattern of a slow moving, widely dispersed species. What type of thinking is required? • Evaluate level: o This question is asking you to weigh and judge, or evaluate, the reproductive mode of an invertebrate. Gather Content What do you already know about reproductive modes? What other information is related to the question? • Individuals within a species that do not move quickly or that are widely dispersed are less likely to encounter each other. • Hermaphroditism is favored when individuals have lower mobility or are more widely dispersed. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The size of an individual does not correlate with its reproductive strategy, so those answers can be disregarded. • Internal fertilization requires two individuals, which might be difficult in a slow-moving, widely dispersed species. • Hermaphroditism would allow self fertilization if no other individual Version 1
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is encountered, or a maximum reproductive rate if another individual of the same species (a conspecific) is present. • A benefit of hermaphroditism is that any conspecific individual encountered is a potential mate. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to weigh and judge, or evaluate, reproductive modes. If you got an incorrect answer, did you remember that slow moving individuals that move slowly are not likely to encounter each other? Did you have trouble weighing the merits of dispersion and reproductive mode to determine the correct answer? 59) C
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Clarify Question What is the key concept addressed by the question? • The concept of gender in fish is addressed in this question. What type of thinking is required? • Evaluate level: o This question is asking you to weigh and judge, or evaluate, the presence of a female fish from a previously male individual. Gather Content What do you already know about the reproductive modes of fish? What other information is related to the question? • A dominant female fish can prevent the development of other fish in the same area. • If the dominant female fish is removed, another fish can develop into a reproductive female. • Sequential hermaphroditism occurs when an individual is one gender at one point in life, and then can reproduce as another gender at a later point in life. • Protandry is a form of sequential hermaphroditism in which an individual reproduces as a male first, then reproduces as a female later. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The events in this example can only be explained by protoandry. An Version 1
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individual was initially male, but was later able to reproduce as a female. • Clownfish are protandrous hermaphrodites. This is the only known mechanism that allows a mature adult male to change into a female. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to weigh and judge, or evaluate, sex determination in fish. If you got an incorrect answer, did you remember that fish can be sequential hermaphrodites, or the that this change can be initiated by the removal of a female fish from a group? Did you have trouble weighing the merits of reproductive modes with environmental cues to determine the correct answer? 60) C
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Clarify Question What is the key concept addressed by the question? • The concept of importance of turtle nest variables is addressed in this question. What type of thinking is required? • Evaluate level: o This question is asking you to weigh and judge, or evaluate, the impact of environmental variables on a turtle nest. Gather Content What do you already know about turtle development? What other information is related to the question? • The gender of a baby turtle is determined by the temperature at which the nest is incubated. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • A fabric dome would not provide protection against something with the strength of a hurricane, nor would it provide protection from other rough weather. • Female turtles do not sit on nests because they are ectotherms and could not provide warmth that way. • Males do not fertilize the eggs after laying -- they use internal fertilization and fertilize the eggs before they leave the female’s body. Version 1
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• Since turtles use temperature-dependent sex determination, the shadows from a tent -- or for that matter, from high-rise hotels on the beach -- can lower the temperature and alter sex ratios. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to weigh and judge, or evaluate, the factors that influence turtle nestlings. If you got an incorrect answer, did you remember that turtles do not provide parental care to their offspring once eggs are laid, or that the sex of a sea turtle is determined by the temperature at which the nest is incubated? Did you have trouble weighing the merits of environmental variables relative to turtle nests to determine the correct answer? 61) B
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Clarify Question What is the key concept addressed by the question? • The concept addressed here is a possible cause of dinosaurian, and not mammalian, extinction based on differences between the two groups. What type of thinking is required? • Evaluate level: o This question is asking you to weigh and judge, or evaluate, differences between mammals and dinosaurs as they relate to the long term survival of each group. Gather Content What do you already know about dinosaurs? What other information is related to the question? • Dinosaurs are grouped with reptiles. • Some reptiles have temperature-dependent sex determination. • Mammals have chromosomally-determined sex determination. • The impact of a meteor creates particulate matter that is cast into the atmosphere. This can impact air quality and as a result of impeded sunlight penetration, temperature. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Both mammals and reptiles require oxygen for cellular respiration, but as warm-blooded creatures, mammals have higher physiological Version 1
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demands overall, and impaired lung function would negatively impact mammals before reptiles. • Effects on hormones and mate recognition would not differ for mammals and reptiles in this instance. • The impact of radiation from a meteor impact would likely have more significant and rapid impacts on both dinosaurs and mammals before it would have an impact on leathery reptilian egg covering. • Like many other reptiles, dinosaurs may have used temperaturedependent sex determination. This would have made them quite vulnerable to temperature changes following the meteor impact, and could have resulted in the rarity of one of the sexes of dinosaurs. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to weigh and judge, or evaluate, the impacts of a meteor impact on the environment of dinosaurs and mammals. If you got an incorrect answer, did you remember that some reptiles, with the possible inclusion of dinosaurs, have temperature-dependent sex determination, or the criteria to compare reptiles and mammals includes the meteor’s influence on environmental temperature? Did you have trouble weighing the merits of mammals vs. dinsoaurs to determine the correct answer? 62) C
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Clarify Question What is the key concept addressed by the question? • The concept addressed in this question is the relationship between offspring number and the strategy of development. What type of thinking is required? • Evaluate level: o This question is asking you to weigh and judge, or evaluate, the effect of the different strategies for development on offspring number. Gather Content What do you already know about strategies for development? What other information is related to the question? • Oviparity involves the external development of fertilized eggs. • All birds, some fish, some amphibians, most reptiles, and very few mammals utilize oviparity. • Ovoviviparity occurs when eggs are fertilized internally, and develop inside the mother’s body. Nutrients are provide entirely by the egg; there is no connection between the mother and her offspring. • Ovoviviparity is found in some fish and many mammals. • Viviparity is the live birth of offspring. Young do receive nourishment from the mother while they develop. • Viviparity is exemplified by nearly all mammalian species, and some fish, amphibians, and reptiles. Choose Answer
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Given what you now know, what information is most likely to produce the correct answer? • Viviparity requires the most allocation of resources, and thus results in relatively fewer, but better prepared offspring. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to weigh and judge, or evaluate, different developmental strategies in fish. If you got an incorrect answer, did you remember that viviparity differs from ovovivparity in fish because the energetic investment of the mother is greater in viviparity, or that oviparity potentially involves the lowest parental effort after eggs are fertilized? Did you have trouble weighing the merits of the different developmental strategies to determine the correct answer? 63) D In internal fertilization, the oocyte is always retained. The population no longer has to synchronize gamete release. Male intromittent organs, such as penises, are often used for internal fertilization, but birds lack such a structure and simply align their cloacas. 64) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about environmental factors that may affect fertility. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the improvement of fertility based on environmental variables. Gather Content What do you already know about spermatogenesis? What other information is related to the question? • Sperm develop at an optimal temperature that is a few degrees cooler than the typical human body temperature. • Failure to maintain a lower temperature during spermatogenesis leads to impaired sperm. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Loud music may have long-term effects on hearing, but its impact on fertility has not been noted. • If contaminated with bacterial, raw vegetable appetizers may be dangerous to pregnant women, but would not pose a threat to the fertility of a man. Version 1
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• Dairy products are not known to impact fertility. • Since sperm develop at an optimal temperature of 34°C, exposure to hotter temperatures can result in disrupted sperm for months. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use spermatogenesis in a new situation. If you got an incorrect answer, did you remember that spermatogenesis must occur in temperatures that are lower than human body temperature, or that warmer temperatures cause defective sperm? Did you have trouble extending the concept of spermatogenesis to determine the correct answer? 65) D
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Clarify Question What is the key concept addressed by the question? • This question is asking about the effects of an alteration of the normal course of spermatogenesis. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the fate of spermatogonia if they were to undergo meiosis. Gather Content What do you already know about spermatogonia? What other information is related to the question? • Spermatogonia are diploid germ cells. They are the cells from which sperm cells are derived. • Spermatogonia produce one primary spermatocyte and one spermatogonium, which are both also diploid cells. • Primary spermatocytes go through meiosis to produce secondary spermatocytes, which are haploid but still have joined sister chromatids for each chromosome. • Secondary spermatocytes complete meiosis to form spermatids, which mature into sperm. Choose Answer Given what you now know, what information is most likely to produce the correct answer? Version 1
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• This is an alteration of the normal events of spermatogenesis, since spermatogonia do not undergo meiosis during spermatogenesis. • The sperm count would not necessary increase, as it is the type of cell, not the number of cells, that differ in this example. • If spermatogonia were to undergo meiosis instead of mitosis, they would lose their ability to replicate further. The result of meiosis is haploid gametes, which cannot replicate further. • Men's lifelong ability to produce sperm is due to the continued renewal of spermatagonia by one of the mitotic progeny remaining a spermatogonium, and not undergoing meiosis. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use spermatogenesis in a new situation. If you got an incorrect answer, did you remember that spermatogonia do not undergo meiosis, or that once a cell undergoes meiosis it cannot replicate further? Did you have trouble extending the concept of spermatogenesis to determine the correct answer? 66) A
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Clarify Question What is the key concept addressed by the question? • This question is asking about the effects on fertility of low FSH and LH levels in a male. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the effects of low FSH and LH counts. Gather Content What do you already know about hormones and fertility? What other information is related to the question? • Several hormones influence human fertility. • The same hormones may influence both male and female fertility. • Follicle stimulating hormone (FSH) stimulates spermatogenesis in males, and follicle development in females. • Luteinizing hormone (LH) stimulates the release of testosterone in males, and ovulation in females. • Insufficient hormone levels can lower fertility in males and females. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since FSH and LH have important reproductive functions in men as well, it is possible that her son may have problems. Version 1
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the role of hormones in fertility in a new situation. If you got an incorrect answer, did you remember that FSH and LH play a role in the fertility of both males and females? Did you have trouble extending the role of hormones to determine the correct answer? 67) A
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Clarify Question What is the key concept addressed by the question? • The concept addressed in this question involves the source of FSH and LH. What type of thinking is required? • Analyze level: o This is an analyze question because you have to unexpected levels of FSH and LH into their component pieces to understand how they function. Gather Content What do you already know about FSH and LH? What other information is related to the question? • The same hormones may influence both male and female fertility in vertebrates. • Follicle stimulating hormone (FSH) stimulates spermatogenesis in males, and follicle development in females. • Luteinizing hormone (LH) stimulates the release of testosterone in males, and ovulation in females. • In males, negative feedback acts when testosterone and another hormone, inhibin, are present. In this case, testosterone inhibits FSH and LH production. Choose Answer Given what you now know, what information is most likely to Version 1
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produce the correct answer? • If the pituitary gland had been removed, the dog’s life would have ended. Additionally, the removal of the pituitary gland would lower the levels of FSH and LH. • Low levels of GnRH would result in low levels of FSH and LH, not elevated levels. • Negative feedback from testes-produced testosterone and inhibin act to inhibit FSH and LH production. In a neutered animal, this negative feedback is absent and FSH and LH levels will be increased. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between testosterone and other hormones, but on your ability to break down, or analyze, the role of negative feedback in regulating these. If you got an incorrect answer, did you remember that components of negative feedback include the inhibition of FSH and LH by testosterone, or that lack of testosterone would raise the levels of FSH and LH in the body? Did you have trouble breaking down the relationships between these hormones to determine the correct answer? 68) B
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Clarify Question What is the key concept addressed by the question? • This question is asking about the effects of castration on male animals. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break the role of hormones and the effects of castration into their component pieces to understand how they function. Gather Content What do you already know about the effects of castration on hormone levels? What other information is related to the question? • Castration is the removal of the testes. • The testes are responsible for producing testosterone. • In males, negative feedback acts when testosterone and another hormone, inhibin, are present. In this case, testosterone inhibits FSH and LH production. • FSH stimulates spermatogenesis in males, and follicle development in females. • LH stimulates the release of testosterone in males, and ovulation in females. Choose Answer Given what you now know, what information is most likely to produce the correct answer? Version 1
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• Testosterone is produced by Leydig cells in the testes, so in a castrated animal this source of testosterone will be absent. • Negative feedback from testes-produced testosterone and inhibin act to inhibit FSH and LH production. In a castrated animal, this negative feedback is absent and FSH and LH levels will be increased. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on understanding what castration is but also how it would affect hormone levels in the male. Testosterone is most immediately affected by castration, but did you remember that the presence or absence testosterone also affects other hormones in the body. Testosterone (along with inhibin) inhibits the secretion of FSH and LH and so if testosterone is absent then FSH and LH secretion is higher. 69) A Since the tiny polar bodies take little of the cytoplasm, this helps produce the large size of the ovum even after two meiotic divisions. 70) D
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Clarify Question What is the key concept addressed by the question? • This question is asking about what may occur if two follicles burst. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the rupture of two follicles. Gather Content What do you already know about follicles? What other information is related to the question? • During each menstrual cycle, usually one dominant follicle emerges. • Follicles contain eggs. • When the follicle ruptures, an egg is released into the Fallopian tube. • Fertilization may occur in the Fallopian tube. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • High estrogen levels occur when menstruation does not occur, so that answer may be disregarded. • Typically one follicle bursts per cycle, releasing one egg that can be fertilized. • If two follicles burst, two eggs are released, and both could be fertilized. The result of the fertilization of two eggs in one cycle is Version 1
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fraternal twins. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the role of follicles in a new situation. If you got an incorrect answer, did you remember that a follicle releases an egg, or that if more than one follicle ruptures, more than one egg is released? Did you have trouble extending the function of follicles to determine the correct answer? 71) D
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Clarify Question What is the key concept addressed by the question? • This question is asking about the age of an oocyte relative to the age of the mother. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the relationship between maternal age and the age of oocytes. Gather Content What do you already know about eggs? What other information is related to the question? • By the time a baby girl is born, her lifetime's supply of oocytes is already formed and arrested in prophase I. • Primary oocytes finish meiosis I in the follicular phase of the menstrual cycle, and meiosis II begins. • Meiosis II arrests in metaphase II. This is the stage that is released from the ovary. • Meiosis II will not be completed until the oocyte is fertilized. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since all of the oocytes that a female has are present before her birth, the age of her oocytes is the same as her age. Version 1
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Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use oocytes in a new situation. If you got an incorrect answer, did you remember that oocytes are present at the birth of a female, or oocytes mature as part of a woman’s monthly cycle? Did you have trouble extending the concept of oocytes to determine the correct answer? 72) D
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Clarify Question What is the key concept addressed by the question? • The concept that is addressed by this question is the role that progesterone and cycle length play in reproduction. What type of thinking is required? • Evaluate level: o This question is asking you to weigh and judge, or evaluate, the effects of low progesterone and short menstrual cycles. Gather Content What do you already know about progesterone? What other information is related to the question? • Progesterone is produced by the corpus luteum. • Progesterone and estradiol cause the thickening of the uterine lining. • A thickened uterine lining is necessary for successful implantation. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Progesterone is relatively low in a normal cycle before ovulation occurs, so low progesterone does not interfere with the development of a follicle or ovulation. • Since ovulation is not impacted by low progesterone, fertilization will not be impacted. • If progesterone is too low, this will cause early menstruation and the Version 1
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uterine lining will be shed before an embryo has a chance to implant. • The main function of the luteal phase of a woman's cycle is to grow and maintain the endometrial lining of the uterus so it is prepared for implantation of a fertilized egg. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to weigh and judge, or evaluate, the effects of low progesterone and short cycle length. If you got an incorrect answer, did you remember that progesterone causes the uterine lining to thicken, or that low progesterone can prevent implantation? Did you have trouble weighing the merits of low progesterone relative to fertility to determine the correct answer? 73) C This secretion of hCG from the embryo is what pregnancy tests measure. 74) E The most common cause of infertility is the eventual failure of ovulation and reproductive cycling around the time of menopause. 75) Section Break 75.1) C 75.2) D
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Clarify Question What is the key concept addressed by the question? • This question is asking you to identify the hormonal levels that characterize implantation. What type of thinking is required? • Apply level: o You are being asked to take what you know and analyze a figure to determine when a specific event is likely to occur. Gather Content What do you already know about implantation? What other information is related to the question? • FSH stimulation causes a follicle to finish the maturation process in the early portion of the cycle. • Increasing estradiol promotes a sudden spike in LH secretion, which in turn promotes ovulation during the mid point of the cycle. At this point the egg can be fertilized. • The corpus luteum, which secretes progesterone and estradiol, finishes maturation at midcycle. • Higher levels of estradiol and progesterone from the corpus luteum inhibit further secretion of FSH and LH. • Estradiol and progesterone are secreted in the last half of a human female’s menstrual cycle to prepare the lining of the uterus for implantation. • For humans, implantation occurs approximately 5-10 days after fertilization. • A decline in estradiol and progesterone triggers menstruation. Version 1
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Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Days 3, 7, and 13 are too early for implantation. On day 3, the shedding of the uterine lining is still underway. Day 7 lining would not be thick enough for implantation, nor would it be on day 13. Additionally, day 13, as is true for days 3 and 7, is before ovulation, so implantation would not be possible. • Day 27 is immediately before menstruation, and the endometrium is not thick enough for implantation. • On day 21, the lining is at its thickest, ovulation has occurred a week or so previously, and implantation would be very possible. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended on your ability to use your knowledge of the female reproductive cycle to analyze the timing of a specific event. If you got an incorrect answer, did you remember that implantation occurs 5-10 days after fertilization, or that the endometrium must be thick enough or implantation cannot occur? Did you have trouble extending the concept of implantation Version 1
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to determine the correct answer? 75.3) A 76) Section Break 76.1) C 76.2) D 76.3) A 76.4) E 76.5) B
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Chapter 52 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) The placenta protects the developing fetus from harmful substances like alcohol or drugs. ⊚ ⊚
true false
CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 2) Which are structures formed from the neural crest? (Check all that apply.) A) a gill chamber ofprimitive chordates B) blastopores C) sensory neuronsof the dorsal root ganglia D) Schwann cells E) olfactory and hearing organs
3)
Which of the following are fetal membranes? (Check all that apply.) A) chorion B) endometrium C) allantois D) amnion E) yolk sac
4)
Which of the following describe the placenta? (Check all that apply.) A) The bloods of themother and the embryo come in close contact without mixing. B) The placenta neutralizes toxins likealcohol and drugs before they reach the fetus. C) Oxygen diffusesfrom the mother to the embryo. D) Carbon dioxidediffuses from the embryo to the mother. E) The placentaprovides nourishment and hormones to the embryo. F) The antibodies made in the embryoprotect the mother from infections.
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5) Which tissues are correctly matched to their progenitor germ layer? (Check all that apply.) A) ectoderm—lining ofthe digestive tract B) ectoderm—epidermis C) endoderm—lining ofthe respiratory tract D) endoderm—muscles E) mesoderm—bloodvessels F) mesoderm—gonads
6)
Which of the following are mechanisms to prevent polyspermy? A) alteringcomposition of exterior egg coat
B) change in membranepotential of egg C) cortical granuleenzymes remove sperm receptors from egg D) special proteins inside the egg comparethe DNA of different sperm, choosing the most adapted one E) toxic molecules exit the egg to attackextra sperm F) vitellineenvelopes lift off surface of egg
7)
Which of the following result from sperm penetration? (Check all that apply.) A) eggs completemeiosis B) haploid nucleus ofegg undergoes final mitotic division C) movement of eggcytoplasm D) outer pigmentedcap of egg cytoplasm rotates toward point of entry E) sharp increase in protein synthesis
8)
Which of the following are derived from mesoderm?
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A) blood B) epidermis ofskin C) heart D) kidney E) lining of thedigestive tract F) lining of the respiratory tract G) muscles H) nervous system I) skeleton J) somites
9)
Which of the following regarding the Spemann organizer is true? (Check all that apply.) A) Signalingmolecules from the organizer inhibit ventral development. B) The dorsal lipcells directly activate dorsal development. C) The organizerdetermines the dorsal-ventral axis. D) The organizerforms in the area of the grey crescent. E) The point of sperm entry determines theorientation of the organizer.
10) You are studying a mutant gene in the fruit fly Drosophila, and you suspect it may be important for eye development. What evidence would support such a claim? (Check all that apply) A) Gene expression in the eye primordia B) Gene expression throughout the head C) Misexpression of wildtype gene results in ectopic eyes D) Misexpression of wildtype gene results in missing or malformed eyes E) Mutant with nonfunctional gene has ectopic eyes F) Mutant with nonfunctional gene has malformed eyes
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MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 11) What event initiates development? A) fertilization B) cleavage C) gastrulation D) organogenesis
12)
What factor has the strongest influence on the cleavage pattern of an embryo? A) viscosity ofalbumin B) amount of yolk C) maturity ofcytoplasm D) oxygen in air
13) In mammals, embryonic cells form an inner cell mass that will become the body of the embryo and a layer of surrounding cells that will become the chorionic membrane and placenta. What are these surrounding cells called? A) blastocoel B) yolk C) blastodisc D) trophoblast
14)
What structure is formed from both fetal and maternal tissue? A) chorion B) placenta C) yolk sac D) amnion
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15) A couple conceives at the beginning of January. During which month will their child be undergoing organogenesis? A) January B) February C) March D) April
16) A couple conceives a child on January 1st. Which day falls within the period of somitogenesis? A) January 3 B) January 7 C) January 17 D) January 31
17) When the placenta is delivered, what event allows secretion of prolactin and milk production? A) a surge ofadrenaline and endorphins B) sudden drop inprogesterone and estradiol C) gradual drop inoxytocin D) sudden rise in FSHand LH
18) New mothers may benefit from the aid of lactation consultants when learning to breastfeed. These consultants give advice on technique, and help the mother to feel relaxed and confident. What hormone is associated with calm, warm emotions and is also critical for the milk let-down reflex?
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A) prolactin B) estradiol C) oxytocin D) mammotropin
19)
What would be the result of a mutation that reduces the amount of acrosomal enzymes? A) Male infertilitydue to inability of the sperm to tunnel through the blastula. B) Male infertilitydue to inability of the sperm to tunnel through the zona pellucida. C) Femaleinfertility due to blockage of sperm from tunneling through the allantois. D) Femaleinfertility due to blockage of sperm from tunneling through thearchenteron.
20) Certain groups of cells move inward from the surface of the blastula in a carefully orchestrated migration called A) blastulation B) archenteronformation C) morulaformation D) gastrulation E) cleavage
21)
The hollow crater formed during gastrulation is known as A) acrosome B) archenteron C) morula D) cleavagefurrow E) trophoblast
22) What developmental event was key to the evolution of the chordates, by forming the notochord and dorsal nerve cord?
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A) morphogenesis B) organogenesis C) gastrulation D) neural crestformation E) neurulation
23)
What factors stimulate uterine contractions and birth? A) FSH andprostaglandins B) LH andprostaglandins C) oxytocin andprostaglandins D) prolactin andprostaglandins E) hCG andprostaglandins
24) size?
What is the period of rapid cell division in which the embryo does not increase in overall
A) syngamy B) cleavage C) neurulation D) meiosis E) crestformation
25)
What pattern of cleavage is characteristic of mammals?
A) holoblasticcleavage with eggs containing little or no yolk B) some yolk, andcleavage resulting in vegetal and animal poles C) meroblasticcleavage with eggs containing almost entirely yolk D) holoblasticcleavage with eggs containing very little yolk, but with the inner cell massconcentrated at one pole E) holoblasticcleavage with eggs containing very little yolk, but with the inner cell massdistributed uniformly
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26) What is the term for segmented blocks of tissue that form on either side of the notochord and are added sequentially? A) blastopores B) gastropores C) somites D) amnioticcells E) sensoryneurons
27)
Which of the following leads to the occurrence of vertebrate sense organs? A) both adrenal medullary cells and sympathetic neurons derive from the neural crest B) neural crest cells form both neurons that carry messages and cartilaginous bars C) the neural crest and associated sensory ganglia D) formation of the endoderm E) formation of the autonomic nervous system
28) The developing embryo of reptiles, birds, and mammals is encased in the fluidfilled_________blank membrane. A) amniotic B) embryonic C) chorionic D) yolk sac E) allantois
29) The human placenta is formed by the interaction of uterine tissue and what extraembryonic tissue?
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A) amnion B) embrion C) chorion D) yolk sac E) allantois
30)
What is the main role of human chorionic gonadotropin? A) It stimulates the release of oxytocin from the mother's pituitary. B) It allows themother to realize she is pregnant, via pregnancy tests. C) It is similar toFSH in stimulating follicle development. D) It maintains thecorpus luteum.
31)
What stimulates milk production in mammary alveoli? A) oxytocin B) prolactin C) chorionicgonadotropin D) progesterone E) estrogen
32) The head of a sperm is capped with an organelle that contains glycoprotein-digesting enzymes. What is this organelle called? A) zona pellucida B) acrosome C) granulosa D) blastula E) neural cap
33)
In human females, what process causes milk production?
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A) Stimulation of thealveoli of the mammary glands by prolactin from the anterior pituitarygland. B) Stimulation of thealveoli of the mammary glands by oxytocin from the anterior pituitarygland. C) Stimulation of thealveoli of the mammary glands by prolactin from the posterior pituitarygland. D) Stimulation of thealveoli of the mammary glands by oxytocin from the posterior pituitarygland. E) Stimulation of thealveoli of the mammary glands by LH from the anterior pituitary gland.
34)
What is the first milk that is produced after birth called? A) prolactase B) colostrum C) hCG D) chorioniclactase E) allantoicase
35)
What are the two components of the human placenta? A) chorionicfrondosum and chorionic villus B) chorionicfrondosum and decidua basalis C) decidua basalisand chorionic villus D) chorionic villusand endometrium E) chorionicfrondosum and amnion
36)
Which of the following activates the egg?
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A) entrance of sperminto the zona pellucida B) contact of sperm with the outside of the zona pellucida C) contact of sperm with the vitelline envelope D) fusion of sperm and egg membranes E) fusion of sperm and egg nuclei
37) In this diagram, which of the following numbers represents the actual event of egg activation?
A) I B) II C) III D) IV E) V F) VI
38)
Which of the following animals undergoes rotational cleavage?
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A) echinoderms B) annelids C) amphibians D) mammals E) reptiles
39) Working in an experimental fertility clinic, a researcher removes one cell from an 8-cell stage chimpanzee embryo. What is the likely result? A) Both the cell and the blastula will die. B) All the cells are already committed and therefore are not viable. C) The embryo fromwhich the cell was removed still remains viable and can form a normalchimp.
40)
Which of the following is an accurate statement?
A) Both diagrams show developmental sequences occurring in the same animal. B) Both diagrams showblastulae. C) Diagram II shows gastrulation in a bird. D) Diagram I showsgastrulation in a frog. E) Diagram I showsgastrulation in a mammal and diagram II shows gastrulation in a reptile.
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41) Removing some fluid from directly around a developing human fetus is performed by inserting a long needle into the belly of the female patient. What extraembryonic membrane will be punctured in this process? A) chorion B) amnion C) chorionicvilli D) external epithelium of mother
42)
What actually begins the uterine contractions which leads to giving birth? A) oxytocin B) prolactin C) estrogen D) prostaglandins E) the movement of the fetus
43) In 1999, researchers found that they could create hybrid embryos between two species of sea urchin that had been separated for 10 million years. By treating eggs to remove the jelly coat, the sperm of the other species was able to fertilize. What step of the fertilization process is normally blocked, preventing hybridization between these species? A) Sperm penetration B) Membrane fusion C) Egg activation D) Nuclear fusion
44) Egg activation by sperm entry is associated with a sudden increase in protein synthesis. What must be true of these proteins?
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A) They are histoneproteins. B) They are smallpeptides. C) They are frommaternal mRNAs. D) They are frompaternal mRNAs.
45) Your research project involves sea cucumbers, a poorly-understood group of echinoderms. You are trying to determine whether they block polyspermy by changing membrane potential like sea urchins do. In the chart below, you have counted the number of embryos that complete normal development after fertilization in either normal or low-sodium artificial sea water (ASW), for each of three sets of experiments. Looking over your data, what do you conclude? cohort
ASW
low sodium ASW (50mM Na)
A
25/25
2/24
B
22/23
1/22
C
24/26
1/27
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A) Sea cucumbers appear not to block polyspermy the same way as sea urchins, which use an influx of that changes the membrane potential. B) Sea cucumbers appear not to block polyspermy the same way as sea urchins, which use an outflow of that changes the membrane potential. C) Sea cucumbers appear to block polyspermy the same way as sea urchins, via an influx of that changes the membrane potential. D) Sea cucumbers appear to block polyspermy the same way as sea urchins, via an outflow of that changes the membrane potential.
46) A research group claims that they have discovered microscopic fossilized embryos, including some at the blastula stage, but other researchers are skeptical. Finally, one student develops a technique for splitting the embryos in half to reveal the substructure. Cutting open the first blastocyst embryo, the student is very excited. “It is a blastula!" she shouts,"Look, you can see the ____________________ inside!” A) granulosacells B) hollowblastocoel C) archenteron D) neural tube
47)
What is the role of cleavage in the early embryo? A) produce biggercells B) produce manycells C) extrude polarbodies D) make the embryolarger E) create germ layers
48) What can you conclude about a species heavily reliant on diffusible morphogens in early development?
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A) They are likely tohave incomplete cleavage (a syncytium). B) They are likely tolack an organizer. C) They are likely tohave activation via a calcium wave. D) They are likely tohave small amounts of yolk and holoblastic cleavage.
49) You are studying the development of a poorly-understood species at the 8-cell stage. You use a laser to zap away a certain one of the eight cells, and discover that part of the gut is missing once the embryos finish development. Your colleague, who is working on a different species, uses the laser to blast away one of the cells in her embryos, zapping each of the possible cells in a set of eight experiments. However, when the embryos finish development, every one is perfectly normal! What can you conclude about the two species? A) The first species has regulative development, the second has nonregulative development. B) The first species has nonregulative development, the second has regulative development. C) Both species haveregulative development. D) Both species have nonregulative development.
50) What would result if an error inside gastrulation caused too few cells inside the archenteron? A) Too little endoderm, resulting in missing gut and organs B) Too little ectoderm, resulting in missing nervous system or skin C) Problems in muscle development D) Too little protoderm, resulting in missing organs
51) What would result if a defect in gastrulation caused too little mesoderm inside the embryo?
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A) Too little endoderm, resulting in missing gut and organs B) Too little ectoderm, resulting in missing nervous system or skin C) Problems in muscle development D) Too little protoderm, resulting in missing organs
52) What would result if too many cells left the surface of the embryo to move inside during gastruation? A) Too little endoderm, resulting in missing gut and organs B) Too little ectoderm, resulting in missing nervous system or skin C) Problems in muscle development D) Too little protoderm, resulting in missing organs
53) To your chagrin, you and your labmate have discovered that you both labeled your petri dishes “A”, “B”, and “C”. How can you distinguish your sea urchin gastrula embryos from her frog gastrula embryos? A) Unlike frogs, sea urchins are deuterostomes, which form the anus first and the mouth second. B) Sea urchin cells migrate inside to form the archenteron, whereas in frogs proliferation of dividing cells from the dorsal lip populate the inside of the embryo. C) Sea urchins haverelatively yolk-poor eggs with similar animal and vegetal poles, whereas frogshave large amounts of yolk distinguishing the vegetal pole from the animalpole. D) Frogs have an animal pole and vegetal pole, whereas urchins have only a vegetal pole.
54) What problem would result from disrupted development of the allantois in both birds and mammals? A) Inability to retain the fluid that surrounds the embryo B) Inability to form the placenta C) Problems with gas exchange D) Loss of nutritional stores
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55) In 1998, researchers found that genes similar to the Drosophila gene tinman are necessary for heart development in vertebrates. What can you conclude about the ancient bilaterian ancestor of insects and vertebrates over 500 million years ago? A) The fly speciesthat eventually gave rise to vertebrates used tinman to make aheart. B) Something aboutheart development requires a gene to have a tinman-like sequence, butthe vertebrate and invertebrate genes arose by convergent evolution -- so theancestor had a similar but not homologous gene. C) The ancientancestor lacked a heart, but already had a tinman-like gene. D) Theancestor had a heart-like structure that was specified by a tinman-like gene.
56) The snakes include some rather short and some incredibly long species, with a variation from about 100 to over 300 vertebrae. What developmental mechanism is the best candidate for changing the number of vertebrae in evolution? A) Changes in genes that lay down extracellular matrix in bone B) Changes in genes necessary for neural crest development C) Changes in genes that control mitosis D) Changes in the somitogenesis clock
57) 400 micrograms a day of folic acid are recommended for all women of child-bearing age. Folic acid helps prevent neural tube defects in the first weeks of pregnancy, before most women even realize they are pregnant (and almost half of pregnancies in the U.S. are unintended). Knowing that folic acid promotes proper neural tube closure, which disease can be prevented by this supplement? A) Spina bifida -- thevertebrae are unfused and may allow the spinal cord to protrude outside thebody B) Horseshoe kidney --the two kidneys are fused together across the midline C) Esophageal atresia-- the esophagous ends in a pouch, unconnected to the stomach D) Chronic otitismedia -- frequent ear infections that can result from blocked eustachiantubes
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58)
What is critical to the development of neural crest cell derivatives? A) close contact withthe notochord B) regulation ofN-cadherin C) muscle developmentgenes like muscle myosin D) strong cellularadhesions that lock the cells in the place of their origin
59) In the famous Spemann-Mangold experiment, what detail was crucial to understanding the result? A) transplanting thenew dorsal lip cells to the same dorsal lip location in the secondembryo B) using geneticallydifferent donor and host frogs C) placing the dorsallip cells deep inside the archenteron D) treating thedorsal lip cells with morphogens before transplanting them
60)
What basic developmental challenge is solved by the organizer? A) enhancingmigration of cells into the interior of the blastula B) assigningdevelopmental fates to cells along the anterior-posterior axis C) creating ananterior-posterior axis by responding to maternally-deposited proteinfactors D) creating adorsal-ventral axis from a spherical ball of cells
61) In blind cave fish, eyes do not form. However, transplantation of the lens from a closelyrelated aboveground fish into the optic cup of the cave fish induces eye development. What does this suggest about the loss of vision in the cave fish?
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A) Primary inductionof the eye fails in the cave fish because the lens lacks some criticalsignal. B) Secondary induction of the eye fails in the cave fish because the lens lackssome critical signal. C) Primary inductionof the eye fails in the cave fish because the optic cup lacks the abilityto receive some critical signal. D) Secondary inductionof the eye fails in the cave fish because the optic cup lacks the abilityto receive some critical signal.
62) What prevents menstruation from occurring in the 10th week when the corpus luteum regresses? A) The follicle takesover secretion of hCG. B) The follicle takesover secretion of estradiol and progesterone. C) The placenta takesover secretion of estradiol and progesterone. D) The cervix takesover secretion of oxytocin and prostaglandins.
63)
What human organ is formed from two genetically-different tissues? A) neural crest B) neural tube C) placenta D) uterus
64) In a normal mammalian birth, how does the body guarantee that birth proceeds to completion?
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A) Via positivefeedback -- stretching of the uterus by the descending fetus induces release ofoxytocin from the posterior pituitary causing even stronger uterinecontractions. B) Via negativefeedback -- stretching of the uterus by the descending fetus induces release ofFSH and LH from the posterior pituitary causing even stronger uterinecontractions. C) Via positivefeedback -- stretching of the uterus by the descending fetus induces release ofprolactin from the posterior pituitary causing even stronger uterinecontractions. D) Via negativefeedback -- stretching of the uterus by the descending fetus induces release ofprostaglandins from the posterior pituitary causing weaker uterinecontractions.
SECTION BREAK. Answer all the part questions. 65) Referring to the figure of sperm penetration and fusion, match the lettered description with the correct numbered step in the figure.
A. Some of the zona pellucida is degraded by acrosomal enzymes. B. Enzymes are released by cortical granules that harden the zona pellucida. C. Sperm and egg fuse at the plasma membrane. D. Sperm penetrates the corona radiata. E. The sperm nucleus dissociates and enters the cytoplasm. F. Additional sperm can no longer penetrate.
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65.1)
Step I
65.2)
Step II
65.3)
Step III
65.4)
Step IV
65.5)
Step V
65.6)
Step VI
66) Choose the letter of the best match from the following: A. third trimester of pregnancy B. second month of pregnancy C. first month of pregnancy D. second trimester of pregnancy E. third month of pregnancy
66.1)
Neurulation occurs.
66.2)
The embryo is now called the fetus.
66.3)
The heart begins to beat.
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66.4)
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Answer Key Test name: Chap 52_13e_Raven 1) FALSE 2) [A, C, D, E] 3) [A, C, D, E] 4) [A, C, D, E] 5) [B, C, E, F] 6) [A, B, C, F] 7) [A, C, D, E] 8) [A, C, D, G, I, J] 9) [A, C, D, E] 10) [A, C, F]
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Clarify Question What is the key concept addressed by the question? • The concept addressed here is the identification of the underlying factors that are used to identify gene function. What type of thinking is required? • Evaluate level: o This question is asking you to weigh and judge, or evaluate, the evidence that can support the identification of the function of a gene. Gather Content What do you already know about the development of structures in an individual? What other information is related to the question? • In general, structures arise from foundational tissues that are known as primordia. • Whether a gene contributes to the formation of a structure can be assessed by looking at the structure when the gene is expressed normally, but also when the gene is expressed abnormally. • If a gene regulates the development of a structure, it would be expressed in the primordia. • If the gene is mutated, such that it was nonfunctional, or if the gene is misexpressed, the structure would not be expected to develop normally. Choose Answer Given what you now know, what information is most likely to produce the correct answer? Version 1
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• If the gene is expressed throughout the head, it could be ruled out as specific to eye development. • Misexpression of the gene would not result in missing eyes if the gene does in fact regulate eye development. • To demonstrate that the gene is involved in eye development, the gene would need to be present in the eye primordia. • The development of ectopic eyes would be an expected result if a gene involved in eye development was misexpressed. • Malformed eyes would be an expected result if a gene involved in eye development was mutated such that it was nonfunctional. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to weight and judge, or evaluate, eye development and gene expression. If you got an incorrect answer, did you remember that a mutated gene that results in a nonfunctional gene product would result in abnormal eye structure, or that to contribute to the development of a structure like the eye, the gene would be expressed in the primordial tissue of the eye? Did you have trouble weighing the merits of eye development relative to gene expression to determine the correct answer? 11) A 12) B 13) D 14) B Version 1
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15) B
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Clarify Question What is the key concept addressed by the question? • This question is asking you to identify the period of organogenesis. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the identification of the time period in which organogenesis occurs. Gather Content What do you already know about organogenesis? What other information is related to the question? • Organogenesis is the formation of organs in their specified locations. • Organogenesis begins before gastrulation ends, which in humans also marks the initiation of the process of neurulation. • In humans, organogenesis begins the 4th week after fertilization. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since organogenesis begins the 4th week after fertilization, and fertilization occurred in early January, organogenesis in this example would occur in February. Reflect on Process
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use organogenesis in a new situation. If you got an incorrect answer, did you remember that organogenesis starts in the 4th week after fertilization, or that fertilization took place in early January? 16) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about the timing of somitogenesis. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the determination of the timing of the appearance of somites. Gather Content What do you already know about somitogenesis? What other information is related to the question? • The mesoderm gives rise to somitomeres, which give rise to somites. • The timing of somitogenesis overlaps that of neurulatiom. The first somites appear in the 3nd week after fertilization. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since somitogenesis occurs in the 3rd week after fertilization, January 3 and 7 are too early, and January 31 is too late. • January 17 does coincide with the 3rd week of the pregnancy in this example. Reflect on Process
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use somitogenesis in a new situation. If you got an incorrect answer, did you remember that somitogenesis occurs in the 3rd week of a human pregnancy, or that the pregnancy in this example was intiated on January 1? 17) B 18) C 19) B
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Clarify Question What is the key concept addressed by the question? • This question is asking you to identify the function of the acrosomal region of the sperm. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the importance of the acrosomal region of the sperm. Gather Content What do you already know about the acrosomal region? What other information is related to the question? • The acrosomal region of the sperm occurs between the nucleus and the front end of the sperm. • The acrosomal region contains digestive enzymes that allow the sperm to penetrate the outer layers of the egg. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The blastula is a stage of growth that occurs after fertilization. Sperm have already reached the egg if a blastula is present. • The allantois is a membrane that is found after implantation has occurred and the pregnancy is well underway. • The archenteron is a feature that marks gastrulation, which also occurs Version 1
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after fertilization. • Without the necessary digestive enzymes, a sperm cell cannot penetrate the outer layers of an egg, which include the zona pellucida. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the acrosomal region of sperm in a new situation. If you got an incorrect answer, did you remember that the acrosomal region aids fertilization or that without it fertilization could not occur? 20) D 21) B 22) E 23) C 24) B 25) D 26) C 27) C 28) A 29) C 30) D 31) B 32) B 33) A 34) B Version 1
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35) B 36) D 37) C 38) D 39) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about the effects of the removal of a blastomere from a mammal embryo. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the fate of a mammalian blastomere. Gather Content What do you already know about early development? What other information is related to the question? • Early cells that form from the divisions of a fertilized egg are called blastomeres. • In mammals, regulative development is present. • With regulative development, blastomeres are not pre-determined to be specific tissue. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • A blastula is not present until multiple cell divisions result in a hollow ball of cells. • In a mammal, these early cells are not yet committed to a developmental pathway. Version 1
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• Since mammals exhibit regulative development, the seven cells that remain could still form all of the necessary germ layers and resulting structures. This embryo could survive. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use early development in a new situation. If you got an incorrect answer, did you remember that mammal development is regulative, or that regulative development means that early cells are not predetermined to be a specific type of tissue? 40) D 41) B 42) D 43) A
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Clarify Question What is the key concept addressed by the question? • The concept addressed here involves the factors that must be dealt with for fertilization to occur. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break hybridization and fertilization into their component pieces to understand how they function. Gather Content What do you already know about fertilization? What other information is related to the question? • For fertilization to occur, sperm must first find and recognize an egg. • Once recognition occurs, sperm must use digestive enzymes that are kept in their acrosomal region to break through the layers around the egg. • Digestive enzymes that work for one species may not work to penetrate the layers of the egg of another species. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since removing the jelly coat allowed the sperm to fertilize the egg, it appears that that was the only barrier to fertilization. Thus, penetration Version 1
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of sperm into the egg was the step that was blocked. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between fertilization and hybridization, but on your ability to break down, or analyze, factors that prevent fertilization. If you got an incorrect answer, did you remember that components of fertilization include the possession of digestive enzymes that are used to penetrate the egg, or that the enzymes of one species may not work for another species? 44) C Protein synthesis immediately after fertilization comes from maternal mRNAs already in the egg. There has not yet been time for any paternal genes to be transcribed for translation. 45) C
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Clarify Question What is the key concept addressed by the question? ● This question is asking you to compare the blockage of polyspermy by sea urchins and sea cucumbers. What type of thinking is required? ● Evaluate level:● This question is asking you to weigh and judge, or evaluate, a data set that looks at the necessity of sodium to block polyspermy in echinoderms. Gather Content What do you already know about fertilization in sea urchins? What other information is related to the question? ● In sea urchins, membrane contact by the first sperm results in a rapid, transient change in membrane potential of the egg, which prevents other sperm from fusing to the egg’s plasma membrane. ● The importance of this event was shown by experiments where sea urchin eggs are fertilized in low sodium, artificial seawater. ● The change in membrane potential is mostly due to an influx of Na+, so fertilization in low sodium water prevents this. Under these conditions polyspermy is much more frequent than in normal seawater. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● The data for the sea cucumbers show a significant decrease in the number of embryos that complete normal development in low sodium ASW compared to normal seawater. ● This is consistent with the idea that the sea cucumbers require an influx of sodium to block polyspermy, as sea urchins do. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Evaluate level:● Answering this question correctly depended on your ability to weigh and judge, or evaluate, the incidence of polyspermy as it relates to sodium content of the environment. If you got an incorrect answer, did you remember that sodium is necessary for some echinoderms to block polyspermy, or that polyspermy results in lack of development or abnormal development? Did you have trouble weighing the merits of the sodium content of the environment to determine the correct answer?
46) B
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Clarify Question What is the key concept addressed by the question? • The concept addressed here is the recognition of the developmental stage known as the blastula. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to identify the diagnostic features of a blastula. Gather Content What do you already know about a blastula? What other information is related to the question? • A fertilized egg is known as a zygote. • As a zygote divides, it does not increase in size. Rather it subdivides, so each generation of cells is smaller than the previous one. • Eventually the new cells form a hollow ball of cells. These cells surround a central cavity called a blastocoel. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The archenteron and neural tube form after the blastula. If either of these structures are present the blastula stage has been left behind. • Granulosa cells are part of an unfertilized egg. If these cells are present it would be too early for a blastula to have formed. Version 1
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• Seeing a blastocoel would be indicative that a blastula is present, as a blastocoel is a characteristic of a blastula. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the nature of a blastula in a new situation. If you got an incorrect answer, did you remember that blastula is a hollow ball of cells, or that in the middle of the hollow ball of cells is a space known as the blastocoel? Did you have trouble recognizing the diagnostic features of a blastula to determine the correct answer? 47) B Following fertilization, the second major event in animal development is the rapid division of the zygote into a larger and larger number of smaller and smaller cells. This period of division, called cleavage, is not accompanied by an increase in the overall size of the embryo. 48) A
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Clarify Question What is the key concept addressed by the question? • This question is asking about the role of morphogens in early development. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the consequences of diffusible morphogen activity. Gather Content What do you already know about morphogens? What other information is related to the question? • Insects have yolk rich eggs and a syncytial blastoderm, in which multiple mitotic divisions of the nucleus occur in the absence of cytokinesis. • Because there are no membranes separating the early embryonic nuclei of insects, gradients of diffusible proteins termed morphogens within the egg’s cytoplasm can directly and differentially affect the activity of these embryonic nuclei, and thus the pattern of the early embryo. • The nuclei eventually migrate to the periphery of the egg, where cell membranes form around each nucleus. Choose Answer Given what you now know, what information is most likely to Version 1
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produce the correct answer? • Insects have yolk rich eggs, so holoblastic cleavage is not typical. • Morphogens are released from organizers, so this answer can be disregarded. • The calcium wave plays a role in fertilization. • Insect eggs are likely to have incomplete cleavage due to the abundance of yolk contained within the egg. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use morphogens in a new situation. If you got an incorrect answer, did you remember that insect eggs are rich in yolk, or that the yolk would interfere with holoblastic cleavage? 49) B
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Clarify Question What is the key concept addressed by the question? • The concept addressed here is the nature of the developmental path of two different species. What type of thinking is required? • Evaluate level: o This question is asking you to weigh and judge, or evaluate, the differing developmental pathways of two species. Gather Content What do you already know about cleavage and developmental pathways? What other information is related to the question? • Cleavage stage embryos often look like a simple ball or disc of similar cells. • In many animals, this appearance is misleading; for example, the unequal segregation of cytoplasmic determinants into specific blastomeres of tunicate embryos commits those cells to different developmental paths. The experimental destruction or removal of these committed cells results in embryos deficient in the tissues that would have developed from those cells. • In contrast, mammals exhibit highly regulative development, in which early blastomeres do not appear to be committed to a particular fate. For example, if a blastomere is removed from an early eightcell stage human embryo, the remaining seven cells of the embryo will “regulate” and develop into a complete individual if implanted into the uterus of a woman.
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Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The first species has nonregulative development, because the loss of one of its blastomeres causes the loss of a structure in the developing embryo. • The second species has regulative development, because any of the blastomeres can develop into a complete embryo. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to weigh and judge, or evaluate, regulative and nonregulative development. If you got an incorrect answer, did you remember that nonregulative development involves blastomeres that are predetermined to be certain tissues, or blastomeres in a species that exhibits nonregulative development can become complete embryos? Did you have trouble weighing the merits of regulative development relative to nonregulative development to determine the correct answer? 50) A
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Clarify Question What is the key concept addressed by the question? • This question is asking about the consequences of a deficiency of cells inside of the archenteron. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the fate of an embryo with too few cells in the archenteron. Gather Content What do you already know about the fate of the archenteron? What other information is related to the question? • Gastrulation creates the three primary germ layers: endoderm, ectoderm, and mesoderm. • The cells in each germ layer have very different developmental fates. • The cells that move into the embryo to form the tube of the primitive gut are endoderm; they give rise to the lining of the gut and its derivatives (pancreas, lungs, liver, etc.). • The cells that remain on the exterior are ectoderm, and their derivatives include the epidermis on the outside of the body and the nervous system. • The cells that move into the space between the endoderm and ectoderm are mesoderm; they eventually form the notochord, bones, blood vessels, connective tissues, muscles and internal organs such as the kidneys and gonads.
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Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Since the cells inside the archenteron give rise to the endoderm, lack of cells here could cause a deficiency in the lining of the gut and its derivatives. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the germ layers in a new situation. If you got an incorrect answer, did you remember that the endoderm is derived from the inside of the archenteron, or that the lining of the gut and its derivatives are derived from the endoderm? 51) C
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Clarify Question What is the key concept addressed by the question? • This question is asking about the consequences of a deficiency of mesoderm cells. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the fate of an embryo with too few mesoderm cells. Gather Content What do you already know about the fate of the mesoderm? What other information is related to the question? • Gastrulation creates the three primary germ layers: endoderm, ectoderm, and mesoderm. • The cells in each germ layer have very different developmental fates. • The cells that move into the embryo to form the tube of the primitive gut are endoderm; they give rise to the lining of the gut and its derivatives (pancreas, lungs, liver, etc.). • The cells that remain on the exterior are ectoderm, and their derivatives include the epidermis on the outside of the body and the nervous system. • The cells that move into the space between the endoderm and ectoderm are mesoderm; they eventually form the notochord, bones, blood vessels, connective tissues, muscles and internal organs such as the kidneys and gonads.
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Choose Answer Given what you now know, what information is most likely to produce the correct answer? • A deficiency of cells in the mesoderm would not necessarily impact the endoderm or the ectoderm. • Since the mesoderm cells give rise to the muscles and other structures, lack of cells here could cause an issue with muscle development. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the germ layers in a new situation. If you got an incorrect answer, did you remember that the mesoderm is the middle germ layer that gives rise to many structures, or that the muscles are one type of tissue that is derived from the mesoderm? 52) B
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Clarify Question What is the key concept addressed by the question? • This question is asking about the consequences of a deficiency of surface cells during gastrulation. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the fate of an embryo with too few surface cells. Gather Content What do you already know about the fate of the surface cells? What other information is related to the question? • Gastrulation creates the three primary germ layers: endoderm, ectoderm, and mesoderm. • The cells in each germ layer have very different developmental fates. • The cells that move into the embryo to form the tube of the primitive gut are endoderm; they give rise to the lining of the gut and its derivatives (pancreas, lungs, liver, etc.). • The cells that remain on the exterior are ectoderm, and their derivatives include the epidermis on the outside of the body and the nervous system. • The cells that move into the space between the endoderm and ectoderm are mesoderm; they eventually form the notochord, bones, blood vessels, connective tissues, muscles and internal organs such as the kidneys and gonads.
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Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The endoderm is derived from the inside of the archenteron, so a lack of surface cells would not affect its development. • Muscles are derived from the mesoderm, so lack of surface cells, which would give rise to the ectoderm, would not affect muscle development. • Since the surface cells give rise to the ectoderm, lack of cells here could cause an issue with deficiencies in the skin or nervous system. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the germ layers in a new situation. If you got an incorrect answer, did you remember that the ectoderm is derived from the outer layer during gastrulation, or that the nervous system and skin are derived from the ectoderm? 53) C
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Clarify Question What is the key concept addressed by the question? • This question is asking you to differentiate the embryos of two different species based on their morphology. What type of thinking is required? • Analyze level: o This is an analyze question because you have to break the embryos of sea urchins and frogs into their component pieces to understand how they differ. Gather Content What do you already know about eggs? What other information is related to the question? • Frogs, as members of the Phylum Chordata, and sea urchins, as members of the Phylum Echinodermata, are both deuterostomes. • Deuterostomes and protostomes are the two major embryological pathways into which animal species can be divided. • Deuterostomes do not form their mouth from the first embryological opening, while protostomes do form their mouth from the first embryological opening. • Animal species differ in the amount of yolk that is deposited in eggs. This can be used to distinguish the embryos of different species. Choose Answer Given what you now know, what information is most likely to Version 1
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produce the correct answer? • Frogs and sea urchins are both deuterstomes, and the differences between protostomes and deuterstomes are not visually apparent at gastrulation, so this answer can be disregarded. • Both sea urchins and frogs have animal and vegetal poles in their embryos, so differentiating them does not involve the lack of either pole. • The yolk content of sea urchin and frog embryos differs significantly, and this can be used to distinguish one from the other. Sea urchin eggs have little yolk, while frog eggs have so much yolk that it displaces the animal pole. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Analyze level: o Answering this question correctly depended not only on distinguishing between sea urchin and frog embryos, but on your ability to break down, or analyze, the differences that are present in the eggs of these creatures. If you got an incorrect answer, did you remember that components of sea urchin eggs include little yolk, or that the yolk in frog eggs is proportionally much greater? Did you have trouble breaking down the differences in egg composition to determine the correct answer? 54) C
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Clarify Question What is the key concept addressed by the question? • This question is addressing the function of the allantois. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to determine the effects of the disrupted development of the allantois. Gather Content What do you already know about the allantois? What other information is related to the question? • During development, the allantois of a bird embryo expands to form a sac that eventually fuses with the overlying chorion, just under the eggshell. • The fusion of the allantois and chorion form a functioning unit, the chorioallantoic membrane, in which embryonic blood vessels, carried in the allantois, are brought close to the porous eggshell for gas exchange. • The chorioallantoic membrane is thus the respiratory membrane of a bird embryo. • The allantois in mammals contributes blood vessels to the structure that will become the umbilical cord, so that fetal blood can be delivered to the placenta for gas exchange. Choose Answer Given what you now know, what information is most likely to Version 1
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produce the correct answer? • The allantois is not involved in retaining fluid around the embryo, so that answer can be disregarded. • Maintaining nutritional stores or building the placenta are not functions of the allantois. • Since the allantois is a respiratory membrane, if its development was disrupted, gas exchange would be impeded. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the nature of the allantois in a new situation. If you got an incorrect answer, did you remember that the allantois is a respirator membrane for bird embryos, or that it facilitates the development of the umbilical cord in mammals? 55) D
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Clarify Question What is the key concept addressed by the question? • The concept addressed here are the characteristics possessed by the hypothesized ancestor of insects and vertebrates that are relevant to the development of the heart. What type of thinking is required? • Evaluate level: o This question is asking you to weigh and judge, or evaluate, the bilaterian ancestor of insects and vertebrates in regards to the development of a heart. Gather Content What do you already know about the tinman gene? What other information is related to the question? • The structure that functions as a heart in Drosophila is the dorsal vessel. • The tinman gene is active in the development of the dorsal vessel. • A similar gene has been found to contribute to the development of heart structure in vertebrates. • The presence of this gene in both Drosophila and in vertebrates is an example of evolutionary conservation. Choose Answer Given what you now know, what information is most likely to produce the correct answer? Version 1
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• Since both flies and vertebrates have hearts and have a tinman-like gene that they use in heart development, the most parsimonious explanation is that their most recent common ancestor also had both these things. • The ancestor of flies and vertebrates was not a fly, but a bilaterian invertebrate that may have had a very simple heart-like structure. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Evaluate level: o Answering this question correctly depended on your ability to weigh and judge, or evaluate, the tinman gene in flies and vertebrates. If you got an incorrect answer, did you remember that Drosophila differs from vertebrates in that the heart-equivalent structure in Drosophila is the dorsal vessel, or the tinman gene plays a role in the development in the dorsal vessel of Drosophila and in the development of the vertebrate heart? Did you have trouble weighing the merits of the tinman gene relative to heart development to determine the correct answer? 56) D
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Clarify Question What is the key concept addressed by the question? • This question is asking about the process of development that yields vertebrae. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the source of the diversity in the number of snake vertebrae. Gather Content What do you already know about the development of vertebrae? What other information is related to the question? • The notochord gives rise to the somites. • The vertebrae, in addition to other structures, are derived from the somites. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The neural crest is unrelated to the development of the vertebrae. • Genes that control mitosis. • The extracellular matrix in bone is not a model for additional bone growth. • Since somites give rise to the vertebrae, a change in the somitogenesis clock, in other words the pace at which somites form, could change the Version 1
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number of vertebrae that form. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the formation of vertebrae in a new situation. If you got an incorrect answer, did you remember that vertebrae are derived from somites, or that a variable number of somites would give rise to a variable number of vertebrae? 57) A
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Clarify Question What is the key concept addressed by the question? • This question is asking about the condition associated with incomplete closure of the neural tube. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to the effects of the incomplete closure of the neural tube. Gather Content What do you already know about the neural tube? What other information is related to the question? • The dorsal ectoderm gives rise to the neural groove. • The neural tube has edges that fuse together early in a human pregnancy to form the neural tube. • The neural tube differentiates into the spinal cord and brain. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • The kidney, Eustachian tubes, and esophagus are not derived from the ectoderm, so these answers can be disregarded. • The neural tube is derived from ectodermal tissue. • There is a relationship between adequate folic acid intake before and in early pregnancy and a decreased chance of spina bifida, which is the Version 1
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result of an incomplete closure of the neural tube. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use the formation of the neural tube in a new situation. If you got an incorrect answer, did you remember that the neural tube is derived from the ectoderm, or that if it does not close, the spinal cord may protrude through the vertebrae? 58) B 59) B 60) D 61) B
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Clarify Question What is the key concept addressed by the question? • This question is asking about the steps in the formation of the eye. What type of thinking is required? • Apply level: o You are being asked to take what you already know and use, or apply, it to eye development. Gather Content What do you already know about eye formation? What other information is related to the question? • Induction is a foundational mode of development in vertebrates. • Primary induction refers to a structure that is derived directly from one of the germ layers. • Secondary induction occurs when a tissue that is already on a set developmental path gives rise to a structure. • Since the optic cup is present, lack of eye development must be due to the lack of a signal to the lens that would carry out secondary induction. Choose Answer Given what you now know, what information is most likely to produce the correct answer? • Primary induction would not be at work here, as the eye is a structure that is derived from tissue that is already on a developmental path. • The optic cup has formed in this fish, so developmental failure is not Version 1
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due to lack of this structure. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? • Apply level: o Answering this question correctly depended on your ability to use induction in a new situation. If you got an incorrect answer, did you remember that primary induction causes the development of a structure from the germ layers, or that secondary induction occurs when a structure develops from tissue with a set developmental path? 62) C 63) C The placenta is formed from a combination of maternal and fetal tissues, which have only 50% genetic identity. 64) A 65) Section Break 65.1) D 65.2) A 65.3) C 65.4) E 65.5) B 65.6) F 66) Section Break 66.1) C 66.2) D 66.3) B Version 1
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66.4) C
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Chapter 53 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) True or False: Haplodiploidy is necessary for eusociality. ⊚ ⊚
true false
CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 2) Which of the following are used by species for navigation? (Check all that apply.) A) landmarks B) magneticfields C) phases of themoon D) stars E) the sun
3) Foraging behaviors are those having to do with which of the following? (Check all that apply.) A) how an animalavoids becoming the prey of a larger predator B) how an animalfinds its food C) how much food ananimal eats D) what an animaleats E) when an animal eats
4)
Which of the following are eusocial (true social) insects? (Check all that apply.) A) ants B) fruit flies C) honeybees D) termites E) wasps
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5)
Which of the following are examples of associative learning? (Check all that apply.) A) classicalconditioning B) cognition C) imprinting D) operantconditioning E) Pavlovian conditioning
6)
In which of the following examples has communication occurred? (Check all that apply)
A) A bird gives analarm call when a hawk approaches, but no other birds are in the area. B) A bird sings fromthe top of a tree in its territory attracting a female of the same species toit. C) A bird sings fromthe top of a tree in its territory keeping other birds of the same species fromtrespassing. D) An ant lays down atrail of pheromones that other ants follow. E) A waggle dancing bee feeds some of thenectar she is carrying to bees attending her dance; they now know what type offlowers she has visited.
7) Which of the following statements comparing the naked mole rat social system with social insect societies are true? (Check all that apply.) A) As with socialinsect societies, colony members are kin. B) As with social insect societies, it is based on haplodiploidy. C) As with social insect societies, there is a division of labor within thecolony. D) As with socialinsect societies, there is one queen and several reproductive males percolony. E) Unlike social insect societies, all colony members are diploid.
8) Herring gulls feed their chicks by regurgitating food for the chick in the nest. When a chick pecks at the red spot on the gull's beak, the parent regurgitates the food. Interestingly, the chicks will peck at any red spot, whether it is attached to a gull or not. Which features of this behavior are correctly labeled? (Check three.)
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A) Fixed actionpattern -- finding a healthy variety of food for the chick B) Fixed actionpattern -- pecking at the spot C) Innate releasingmechanism -- neural circuit that induces pecking in response to a red spot D) Innate releasingmechanism -- the red spot E) Key stimulus --the shape of the parent's beak F) Key stimulus --the regurgitated food G) Key stimulus -- the red spot
9) Male fruit flies perform a complex mating dance that includes following the female, vibrating a wing to produce a species-specific song, and picking up chemosensory cues by tapping with the legs and licking with the tongue. What physiological features are likely important for causing this behavior? (Check all that apply) A) adaptive value ofsuccessful mating B) brain circuits C) hormones D) natural selection E) performance ofphylogenetically-related species F) sensory neurons onthe legs and tongue G) spermcompetition H) threats ofpredation during the performance I) visual system J) wings and wing muscles
10) Which of the studies below provide evidence linking genes and behavior? (Check all that apply) A) Fruit flies that are mutant for the genes dunce or rutabaga have impaired learning. B) Mice that arelacking either the ephrinB3 or the EphA4 gene cannot walknormally, but instead hop like a kangaroo. C) Two lines of fruit flies were created by repeatedly selecting for high orlow aggressive behavior. After multiple generations, the high line was reliablymore aggressive than the low line. D) Twin studiescomparing monozygotic and dizygotic twins have found a high heritability forheight, although environmental influences like nutrition also play a role.
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11) You've finished your homework, so you settle into your favorite chair to play your video games. "Going into your Skinner box?" your roommate jokes. What does a video game have in common with the traditional Skinner box? (Check all that apply)
A) conditionedstimulus is associated with a reward B) food pellets aredispensed C) involvesinvoluntary behavior by the subject D) involves voluntarybehavior by the subject E) rapid feedback F) rat subjects G) repeated series ofactions and rewards
12) Based on the animal cognition experiments you have learned about, if you wanted to design a test of animal cognition, what might you include in your experiment? (Check all that apply) A) Count the numberof individuals in a colony. B) Create a problemfor the animal to solve, like getting a treat out of a box. C) Determine ahead oftime what parameters to record as data, such as how long it takes the animal toretrieve the treat. D) Determine thehormonal basis of caste differences. E) Expose the animalto the same scenario again later. F) Focus on carefulquantitative analysis of fixed action patterns. G) Include a negativecontrol. H) Include multiplesubjects. I) Measure thefrequency of response to sign stimuli. J) Provide tools forthe animal to use.
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13) Swordtail fish are known for the long extensions on the males' tails. What types of experiments might help you determine whether the females are using visual input about tail length to choose between males? (Check the best three) A) Add artificial tails of different lengths to females and determine their response to normal males. B) Add artificial tails of different lengths to male platys (a similar fish without tail extensions), and measure female response. C) Create artificial fish models with different size tails and measure female response. D) Measure hormone levels in males who have different size tails. E) Measure sperm count in males who have different size tails. F) Trim the tails of male fish to different lengths and measure female response.
14) What are likely outcomes for a female who is not choosy enough, and has too broad of an acceptance of reproductive signals? (Check all that apply.) A) Her sons may havelow success attracting mates. B) Her fitness willbe improved because she never misses a chance to mate. C) She may mate withmales who are sick with parasites or disease. D) She may mate withmales with less adaptive genes. E) Her fitness goesup due to increased efficiency by not wasting time in lengthy evaluations. F) She might inadvertently mate with a different species.
15) What sensory modalities are used by the message receivers in honeybee waggle dance communication? (Check all that apply.) A) auditory B) autonomic C) chemosensory D) proprioceptive E) visual
16)
What three features define eusociality? (Check three.)
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A) colony resides inan enclosed hive or nest B) cooperative broodcare C) haplodiploidy D) insect species only E) overlap ofgenerations F) reproductivedivision of labor G) reproduction during a mating flight
17)
What would be included under the umbrella of "inclusive fitness"? (Check all that apply.) A) reproduction by ananother individual that practices reciprocal altruism B) reproduction ofthe individual C) reproduction bynieces and nephews D) reproduction byunrelated colony members E) reproduction bysiblings
18) Which are examples of advantages that different species might have due to living in a group? (Check all that apply.) A) Wolves in a packcan take down larger prey than those alone. B) Zebras in a herdhave added protection from predators. C) Because of theirsocial nature, diseases like rabies can spread quickly through a batcolony. D) A colony of termites can build mounds over 20 feet high, with elaboratetunnels and ventilation systems. E) A flamingo in a large flock may havetrouble competing for food.
19)
Which features of naked mole rats are similar to eusocial insects? (Check all that apply)
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A) a single queen isresponsible for breeding B) colony has a largenumber of individuals C) division oflabor D) haplodiploidy E) higher relatedness between siblingsthan between parent and child
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 20) Tinbergen is credited with being one of the founders of the field of behavioral ______, the study of how natural selection shapes behavior. A) genetics B) ecology C) symptomatology D) demographics
21) Animals tend to feed on prey that maximize their net energy intake. This is called the __________ theory. A) competitive exclusion B) maximal consumption C) optimal foraging D) optimization
22) In many animals, ______ guides learning by determining what type of information can be learned, meaning that what an animal can learn is often biologically influenced.
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A) instinct B) free will C) consciousness D) operance
23) The degree of parental investment required often results in the nonrandom mating behavior called __________. A) allopatry B) fidelity C) mate choice D) preferability
24)
Alarm calling seems to be an example of _______, that is, it favors relatives. A) sociology B) demography C) aggression D) kin selection
25) Chemical signals that mediate interactions between two or more members of a given species are called _______________. A) pheromones B) alarm signals C) hormones D) competitive exclusions
26)
Artificial selection and hybridization can demonstrate the __________ basis of behavior.
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A) cognitive B) operant C) genetic D) associational E) endogenous
27) A nonassociative learning called __________ can be defined as a decrease in response to a repeated stimulus that has no positive or negative consequences. A) instinctive learning B) imprinting C) desensitization learning D) habituation E) cognitive learning
28) As an animal matures, it forms attachments to other individuals and develops preferences. This process is called A) instinct. B) imprinting. C) associational learning. D) habituation. E) sensitization.
29) The processing of information and response in a manner that suggests thinking in the animal is called A) endogenous behavior. B) environmental induced behavior. C) instinctive behavior. D) associative behavior. E) cognitive behavior.
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30)
The signal from the environment that triggers a stereotyped behavior is a A) conditioned reflex. B) fixed action pattern. C) reinforcing stimulus. D) releasing mechanism. E) key stimulus (sign stimulus).
31)
By evaluating and selecting mates with superior qualities, an animal can increase its A) reproductive success. B) learning. C) competitive strategies. D) foraging efficiency. E) length of life.
32) In birds, if the offspring require extensive care, usually involving both the male and female, they are called A) semelparous species. B) altricial species. C) precocial species. D) iteroparous species. E) sympatric species.
33)
The modification of behavior as a result of experience is called
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A) association. B) behavior modification. C) habituation. D) learning. E) sensitization.
34)
Habituation belongs to which of the following types of learning? A) nonassociative B) behavior modification C) conditioning D) innate release E) cognitive
35) If an unrelated stimulus, such as the ringing of a bell, was presented at the same time as the meat powder, over repeated trials, a dog would salivate in response to the sound of the bell alone. This kind of response is called A) behavioral learning. B) classical conditioning. C) deviant behavior. D) operant conditioning. E) imprinting.
36)
An animal learns to associate its behavioral response with a reward or punishment in A) behavioral learning. B) classical conditioning. C) deviant behavior. D) operant conditioning. E) imprinting.
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37)
Who conducted the famous "imprinting" experiment on geese? A) Mendel B) Russel C) Lorenz D) Darwin E) Raven
38) Research has revealed that the development of psychological well-being and growth is influenced by A) imprinting. B) physical contact. C) sensitization. D) associative learning. E) pheromone levels.
39) A behavior that has evolved to aid relatives, although at personal risk, and thus increases the chance of your genes being passed on to the next generation is known as A) altricial behavior. B) instinctive behavior. C) kin selection. D) operant conditioning. E) adaptive behavior.
40) Which scientist described inclusive fitness as the effect an individual has on propagating its alleles through its own reproduction and through kin selection?
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A) Mendel B) Darwin C) Wallace D) Tinbergen E) Hamilton
41)
Social insect colonies are composed of highly specialized groups called A) clines. B) ecotypes. C) castes. D) species. E) filial relatives.
42) Insect workers propagate more of their own alleles by helping their mother reproduce rather than by reproducing themselves; thus, they share a larger fraction of their ___________ with the next generation. A) food resources B) time C) genome D) ability to defend their nest E) home
43)
Courtship is often dependent on A) social releasers. B) a stimulus/response chain. C) an alarm call. D) taxis. E) size and colors.
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44) Foraging bees communicate with other bees in a waggle dance to give information about the food. The important cue in the dance that conveys information about the required flight direction to the food source relative to the hive-sun direction is the A) angle between the food source and the hive in reference to the sun. B) angle between the waggle run and the vertical axis within the hive. C) angle between the waggle run in reference to the hive-sun angle. D) angle between the waggle run in reference to the direction north from the hive. E) speed of the waggle dance.
45) If a scientist is conducting a study of how an animal's senses provide a physiological basis for a particular behavior, what type of causation is being explored? A) ultimatecausation B) proximatecausation C) stereotypedcausation D) ethnologicalcausation E) fixed actionpattern causation
46) If a scientist is conducting a study of how a male bird's song and the female bird's response evolved, what type of causation is being explored? A) ultimatecausation B) proximatecausation C) stereotypedcausation D) ethnologicalcausation E) fixed actionpattern causation
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47)
Which of the following is an appropriate interpretation for these graphs?
Maternal care (as measured by minutes crouching over offspring and proportion of pups retrieved) in female mice that have the fosB allele is A) less than the maternal care given by female mice without the fosB allele. B) greater than the maternal care given by female mice without the fosB allele. C) the same as the maternal care given by female mice without the fosB allele. D) less than the maternal care given by female mice without the fosB allele; however, the graphs depict only minor differences, which are most likely not significant. E) not possible to determine from the data.
48) In an experiment studying predator and prey relationships, a scientist offers a naïve toad a bumblebee as food. The bee stings the toad when the toad tries to catch and eat the bee. Subsequent feeding trials with the toad reveal that the toad avoids feeding on bumblebees. This is a demonstration of A) non-associative learning on the toad's part. B) associative learning on the toad's part. C) ultimate learning on the toad's part. D) proximate learning on the toad's part. E) sign stimulus learning on the toad's part.
49) B. F. Skinner first introduced operant conditioning experiments. What happens in these experiments?
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A) An animal learnsto associate its behavioral response with a fixed action pattern. B) An animal learnsto associate its behavioral response with an instinct. C) An animal learnsto associate its behavioral response with its biological clock. D) An animal learnsto associate its behavioral response with a reward or a punishment. E) An animal learnsto associate its behavioral response with a conditional stimulus.
50) Konrad Lorenz demonstrated that newly hatched birds would direct their social behavior toward him if they saw him first after they hatched from their eggs. What is this called? A) cross-fosteringbehavior B) operantconditioning C) fixed actionpatterning D) habituationbehavior E) imprintingbehavior
51) A friend of yours is wondering about the differences between the words orientation and navigation when these two terms are used in descriptions of bird migrations. Since you have studied and know something about animal behavior, what do you tell your friend? A) Orientation isadjusting a bearing, while navigation is actually following a bearing. B) Orientation andnavigation are used interchangeably when referring to avian migrations. C) Orientation isfollowing a bearing, while navigation is setting or adjusting a bearing. D) Orientation isfollowing the sun in the day as starling do, while navigation is following abearing with a small amount of magnetite, which is found in the heads of somemigratory birds. E) Orientation is theability to find true east, navigation is the ability to find a bearing whilecrossing water.
52) The area over which an animal moves in the course of daily activity, but which it does not necessarily defend against other animals, is called what?
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A) family home B) foraging space C) home range D) nesting site E) territory
53) In species where the young are precocial, meaning requiring little parental care, males may be more likely to be A) monogamous. B) polygynous. C) polyandrous. D) altricial.
54)
Living as a member of a group may have all of the following advantages except A) being more resistant to disease and parasites. B) increased feeding rate. C) greater protection from predators. D) members learn about new food sources from other members. E) more individuals scan the environment for dangers.
55) Haldane pointed out that if he received a certain allele, the chance that one of his brothers would receive that allele would be A) 100%. B) 50%. C) 10%. D) random. E) 0%.
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56)
What is the term for selection that favors altruism toward relatives? A) kin selection B) mate choice C) groupselection D) nepotism E) reciprocalaltruism
57) Hamilton explained the origin of altruism in selected insect societies with his kin selection model of sex determination. Since males are haploid and females are diploid, the workers share a very high proportion of alleles, theoretically as high as 75%. What is this called? A) diploidy B) haploidy C) haplodiploidy D) parthenogenesis E) altruism
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58) Which of the following is the best interpretation of the graph below of mussel size (xaxis) versus energy gain (line graph, left y-axis), and number of mussels eaten per day (histogram, right y-axis)?
A) Mussels are selected as food sources by crabs. B) Crabs select mussels in a way that maximizes their energy gain. C) Mussel size does not seem to be a good predictor as to which mussel hungry crabs will select. D) Crabs tend to consume most of the largest mussels. E) Crabs prefer the mussels with the smallest length for their food resources.
59) Your study buddy asks, "would you please explain the difference between home range and territory?" What is the best response?
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A) Territory is the entire area that an animal can utilize for its resources, such as shelter, food, and mates. Home range is near its nest or den. B) Territory is the area that an animal can utilize for its resources, such as shelter, food and mates and will defend against other members of its species. Home range is near its nest or den. C) Territory is the area that an animal can utilize for its resources, such as shelter, food and mates, and will defend against other members of its species. Home range is the area that an animal may roam over on a daily basis. D) Territory is the area that an animal can utilize for its resources, such as shelter, food and mates, and will defend against others members of its species. Home range is a smaller area within the territory that the animal is found in when it is resting or hiding from predators.
60) What is the flash pattern used by female fireflies to attract males of their species an example of? A) a signstimulus B) an innatereleasing mechanism C) a supernormalstimulus D) sexualimprinting
61) The vertical dive of a moth for cover when it hears the ultrasound chirps of an approaching bat is an example of a(n) A) sign stimulus. B) fixed action pattern. C) innate releasing mechanism. D) supernormal stimulus. E) kinesis.
62) The neural circuit that allows a male stickleback fish to orient and behave aggressively towards an inanimate object with a red stripe is an example of a(n)
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A) sign stimulus. B) fixed action pattern. C) innate releasing mechanism. D) supernormal stimulus. E) stimulus-response chain.
63) When a parent herring gull arrives at the nest with food, a chick will orient to and peck at the red spot on the parent's bill. The parent will then regurgitate the food into the chick's open mouth and the chick swallows it. What is this set of behaviors an example of? A) sign stimulus B) fixed actionpattern C) innate releasingmechanism D) taxis E) stimulus-responsechain
64) You place an empty dog-food dish across the room from a puppy that then goes over to investigate the dish. You pick the dish up and ten minutes later you place it in a different part of the room, and you keep repeating this pattern. After the fifth time the puppy no longer goes over to the empty dish. Which of the following terms best describes this form of learning? A) trial and error learning B) habituation C) classical conditioning D) operant conditioning E) imprinting
65) It is 6:00 PM and the sun is due west of the hive. A honeybee has just returned to its hive from a patch of flowers that are due north of the hive. Which of the following best describes the type of waggle dance that this bee should perform? Note: The waggle run is the straight part of the dance.
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A) The waggle run should be straight down the vertical axis. B) The waggle run should be straight up the vertical axis. C) The waggle run should be 90° to the left of the vertical axis. D) The waggle run should be 90° to the right of the vertical axis. E) The waggle run should be 45° to the right of the vertical axis.
66) Correctly rephrase the following famous quote from J. B. S. Haldane. "I would lay down my life in order to save two brothers or __________________." A) one son or daughter B) four cousins C) three uncles D) two nephews and one son or daughter E) two grandsons or granddaughters
67)
Which of the following statements best defines an altruistic act? A) benefits the performer and another individual B) benefits another individual at some cost to the performer C) benefits another, related individual at some cost to the performer D) imposes a cost on the performer and another individual E) imposes a cost on the performer without benefiting another individual
68) One of your professors says that fleas jump so high because they have specially adapted leg structures and muscles. But your other professor says that fleas jump high because evolution selected for individuals with genes that helped them avoid being damaged by the scratching behavior of their host. So -- why do fleas jump high?
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A) Because they havespecially adapted leg structures and muscles. B) Because evolutionselected for individuals with genes that helped them avoid being damagedby the scratching behavior of their host. C) The ultimate causeis that they have specially adapted leg structures and muscles, and theproximate cause is that evolution selected for individuals with genes thathelped them avoid being damaged by the scratching behavior of theirhost. D) The proximatecause is that they have specially adapted leg structures and muscles, and theultimate cause is that evolution selected for individuals with genes thathelped them avoid being damaged by the scratching behavior of theirhost.
69) Female fire beetles, Melanophilia sp., must seek out freshly-burned trees to lay their eggs in so the larvae can feed on the burned wood. What specialized neural structures might you expect these beetles to have to facilitate this behavior? A) Extra large axons for rapid axonal transduction B) Special, enlarged synapses for rapid synaptic transmission C) Giant brain structures for processing auditory information D) Special sensory structures that can detect signs of fire or burned wood
70)
Which best describes the role of neurotransmitters in behavior?
A) In specificecological contexts, neurotransmitters can be important for behavior. Forinstance, aggression requires the neurotransmitter serotonin. B) Some specificbehaviors will require neurotransmitters. For instance, aggression requires theneurotransmitter serotonin. C) Neurotransmittersallow neurons to communicate, and are thus involved in all behaviors. Levels ofspecific neurotransmitters have been associated with levels of specificbehaviors -- such as serotonin and aggression. D) Neurotransmittershave been developed for researchers who want to manipulate animalbehaviors. For instance, serotonin can be applied to lobsters to increaseaggression.
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71) At a research conference, you meet a graduate student who studies the hormonal underpinnings of mating behavior in two species of squirrel. "It turns out the difference between my two squirrel species is similar to the difference between the prairie and the montane voles," he says. You nod knowingly, and reply... A) "Oh, so thepromiscuous species has a lot of vasopressin and oxytocin receptors in thenucleus accumbus, blocking pair bonding, and the monogamous speciesdoesn't?" B) "Oh, so themonogamous species has a lot of vasopressin and oxytocin receptors in thenucleus accumbus, promoting pair bonding, and the promiscuous speciesdoesn't?" C) "Oh, so thepolyandrous species has a lot of serotonin and dopamine receptors in thenucleus accumbus, promoting pair bonding, and the promiscuous speciesdoesn't?" D) "Oh, so themonogamous species has a lot of serotonin and dopamine receptors in thenucleus accumbus, promoting pair bonding, and the promiscuous speciesdoesn't?"
72) Your study buddy is frustrated. "This book says that a single gene can make mice exhibit a certain behavior. That's ridiculous! How can you build any kind of neural circuit with just one gene?" What is your response? A) "If the booksays so it must be true. Ours is not to question why." B) "Some genes arelonger than others, over 1000kb -- they have enough information to encode afull neural circuit." C) "Mice are a lotsimpler than we are, and their brains are smaller. One gene is plenty for themto build a circuit." D) "What the bookreally means is: all else being equal, one variant of a gene is associated withhigher levels of the behavior than the other variant of the gene. All the otherthousands of genes are still needed to develop the brain. But variation in onegene can change how a certain neural circuit will behave."
73) A bear at a national park has discovered that if it can open the lid of the trash cans, it is likely to find tasty food inside. Soon it is trying to open the trash cans all over the park. What mechanism of learning has occurred? A) classical(Pavlovian) conditioning B) habituation C) operantconditioning D) airconditioning
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74) You read about how learning preparedness influences the associations that an animal is capable of learning. You want to explore the learning preparedness of hamsters. How might you test the learning preparedness of this species?
A) Train hamsters tonavigate a maze to reach a reward. Determine which hamsters are fastest --thus, are most prepared to learn. B) Train hamsters tonavigate a maze to reach a reward. Determine the time of day at which thehamsters are fastest -- thus, most prepared to learn. C) Train hamsters tochoose between tunnels to find a reward. Switch the reward tunnel frequently,and determine which hamsters learn the new association the fastest. D) Train hamsters tochoose between tunnels to find a reward, and mark the tunnels with differentvisual, tactile, chemosensory or auditory stimuli to see which associations arelearnable.
75) You work in a lab that studies bird brains and behavior. You and your labmate have both submitted brains to a colleague to be sectioned. Your species is a bird that is known for storing large numbers of nuts each autumn in a variety of hidden locations. Your labmate's species is a raptor known for remarkable predatory behavior. What do you anticipate will be different between the two brains? A) Your nut-hidingspecies is likely to have a large hippocampus, while the raptor may have alarge visual system. B) Your nut-hidingspecies is likely to have a large visual system, while the raptor may have anlarge hippocampus. C) Both species arelikely to have a large nucleus accumbens. D) Your nut-hidingspecies is likely to have a large hypothalamus, while the raptor may have anlarge olfactory system.
76) In its youth, a pet parrot was owned by someone who kept the wings clipped and never allowed it to fly. Later in life, the new owner let the feathers grow and let the parrot fly around the house. But the parrot kept knocking over lamps and crashing into walls. "Wow," said the owner, "I guess parrots are just too clumsy to fly around a house without destroying everything." What is an alternative explanation?
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A) In nature, parrotshave much more room to fly, and do not have to navigate around delicate homedecor. B) Since the parrotwas not able to practice flying during the critical period for flightdevelopment, the brain circuits for accurate flying were not able todevelop. C) The parrot justneeds more practice flying -- although it did not get to fly when young, thisshould not affect later ability. D) The critical periodfor flying development in the brain has just now begun with the bird's firstattempt. In a few weeks the critical period will end, so it must practiceduring this time.
77) A bird sanctuary sometimes takes over the care of eggs or chicks of an endangered duck species if the parents are killed. They are sometimes able to use mothers of farm ducks to crossfoster the chicks, but it doesn't always work. Looking at the following data table, what is the critical period for imprinting in this species? (Note: DAH stands for "days after hatching".) Number of chicks
Age of chicks when Successful imprinting? paired with foster mother (assessed at 14 DAH)
13
eggs (0 DAH)
yes
7
1 DAH
yes
11
3 DAH
yes
5
8 DAH
no
9
11 DAH
no
A) The critical period extends from 1 to 3 DAH. B) The critical period extends from 3 to 8 DAH. C) The critical period ends sometime between 1 and 3 DAH. We can not determine from this data when the critical period begins. D) The critical period ends sometime between 3 and 8 DAH. We can not determine from this data when the critical period begins.
78) You are on the committee to update the design of the hospital NICU (neonatal intensive care unit), which currently has incubators for the babies but not much else. Based on what you have learned about Harlow's experiments with rhesus monkeys, what would you suggest adding to the NICU to improve the babies' health and well-being?
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A) comfortable chairsfor parents to hold their babies B) softer lighting C) white-noise devicesto mask the sound of beeping machines D) pheromones
79) A zoo is hand-rearing a group of orphaned white-crowned sparrows. What is the best approach to help prepare the males to attract mates when released into the wild? A) Expose the males to a mentor male bird singing their species' song during the critical period. B) Expose the males tofemale pheromones from their species, to initiate development of song circuitsduring the critical period. C) Expose the males toeach other during the critical period, to initiate development of song circuitsduring the critical period. D) Expose the males toa variety of birdsongs during the critical period.
80) One spring, your friend living in Minnesota eagerly sets up her new hummingbird feeders, and is thrilled to watch hummingbirds feeding on the nectar. However, she is disappointed when after just a week or two the hummingbirds disappear. What advice would you give her? A) Set up a bell(conditioned stimulus) near the feeders so the hummingbirds make an associationwith the food. B) Set up flashingred lights that mimic the male neck feathers -- that should attract moremales to the area. C) Set up the feedersagain in the fall. The hummingbirds may have briefly traveled through duringtheir annual spring migration. D) Wait till nextyear -- hummingbirds are a high-metabolism, semelparous species and havealready reproduced and died.
81) Research on starlings indicates that young birds migrate by _______________, but older birds use true __________________.
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A) orientation;navigation B) navigation;migration C) migration;orientation D) navigation;orientation
82) Which statement best sums up our understanding of how animals navigate during migration? A) The mechanismshave been worked out in great detail, from the genes involved, to thebrain structures, to the resulting behavior. B) We have a thoroughunderstanding of orientation but not navigation. C) We have someunderstanding of the information different animals rely on (sun, stars, ormagnetic fields), and some sensory structures, but beyond that the mechanismsare still mysterious. D) Animal navigation is a complete mystery.
83)
If a behavior has evolved by natural selection, it must have ______________. A) benefits for bothmales and females B) reduced thepredation rate on the animal C) evolved the sameway in each species D) a genetic basis
84) Male hummingbirds flash a patch of iridescent feathers on their neck called the gorget. This behavior makes them very visible. Why advertise their presence to a predator?
A) Hummingbirds are so fast that predation is not a large factor forthem. B) Predators cannotsee colors so are not alerted. C) The benefits ofdefending a territory exceed the costs of predation. D) This is an exampleof a maladaptive behavior that decreases overall fitness.
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85) In the phalarope, or wadepiper bird, the male is unusual in playing the larger parenting role -- he performs all the egg incubation and chick care. What unusual behavior might you predict for the female of the species? A) The female providessperm to fertilize the male's eggs. B) The female is partof a large harem of females, under the domain of a single male. C) The females competeto mate with the males, who choose among them. D) The females havedull, brown coloring that keeps them well-camouflaged.
86) A certain species has offspring that require a very large amount of parental care. Predict their mating system. A) monogamous B) polyandrous C) polygynous D) monotonous
87)
In regards to altruism, what way are humans like vampire bats? A) Their altruism isbased on haplodiploidy. B) They are bothChiroptera. C) Their altruism isbased on kin selection. D) They engage inreciprocal altruism.
88)
Which of the following genes would most likely play a role in promoting kin selection?
A) wingless -- critical for the formation of wings in fruit flies B) SRY -- thegene that initiates male sex determination C) MajorHistocompatibility Complex (MHC) genes -- allow mammals to recognize relatedindividuals D) the genes important for the development of large antlers in the caribou
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89) Due to reproductive isolation, a new species of weaver bird is evolving. Is it likely to use a social or solitary nesting strategy? A) It depends onwhether it lives in the forest or the open savanna. B) It depends onwhether it lives in near water or near the desert. C) It depends on howmany similar species it is competing with. D) It depends on howmany eggs it lays.
90) Which statement concerning the evolution of attending and feeding behaviors in poison dart frogs is supported by the phylogeny?
A) Dendrobates leucomelas is the species where these behaviors first arose. B) The common ancestor of Ameerega trivittata, and all other species, provides the first example of male transportation and attendance. C) Oophaga speciosa are the only species to demonstrate female transportation and attendance. D) Male transportation and attendance evolved very recently and there has not been time for female transportation and or attendance to evolve from this norm.
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91)
What is the evolutionary advantage of extra-pair copulations in birds?
A) For males, increased reproductive success and for females, the chance to mate with genetically superior individuals. B) For males, the chance to mate with genetically superior individuals and for females, increased reproductive success. C) For males, increased reproductive success and for females, the chance to have other females (thought to be the sisters of the mates) assist with the rearing of the offspring. D) For males, the chance to have other females (thought to be the sisters of the mates) assist with the rearing of the offspring and for females, increased reproductive success.
SECTION BREAK. Answer all the part questions. 92) Choose the letter of the best match from the following: A. cognition B. waggle dance C. navigation D. filial imprinting E. fixed action pattern
92.1)
Information processing that suggests thinking.
92.2)
Move long distances using sun and stars.
92.3)
A form of communication in honeybees.
92.4)
Innate motor program.
92.5)
Social attachments are formed between parents and offspring.
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93) Lepidopterans (moths and butterflies) sometimes have specialized flying behaviors. Some moths have the ability to do sudden vertical drops when they detect bat sonar, to avoid being eaten. Other species use special flying techniques to attract a mate. When biologists talk about the "cause" of a behavior, they may be referring to two different things. The proximate cause is the sequence of physiological events that lead to the behavior in an individual. The ultimate cause is the adaptive benefit to the animal that allowed natural selection to sculpt the behavior over evolutionary time. Understanding both the proximate and ultimate basis of behavior is important, and different types of biologists may focus on each.
93.1) A moth species is known for its unusual flying behavior, which includes sudden vertical drops and horizontal zigzags. Not much is known about the cause of this behavior. What could you study to better understand the proximate basis of this behavior? (Check all that apply) A) brainstructure B) flying behavior inrelated species C) hormones D) matingbehavior E) physiology F) predation G) sensory organs H) wing muscle development
93.2) What could you study to better understand the ultimate basis of this behavior? (Check all that apply) A) brainstructure B) flying behavior inrelated species C) hormones D) matingbehavior E) physiology F) predation G) sensory organs H) wing muscle development
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Answer Key Test name: Chap 53_13e_Raven 1) FALSE Not necessarily. Termites and naked mole rats have complex societies, but do not have haplodiploidy. However, haplodiploidy does seem to favor the evolution of eusociality, because it increases the relatedness of female siblings (75%) compared to mothers and progeny (50%). 2) [A, B, D, E] 3) [B, C, D, E] 4) [A, C, D, E] 5) [A, C, D, E] 6) [B, C, D, E]
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Clarify question: What is the key concept addressed by the question? The question is asking about situations that involve communication. What type of thinking is required? This is an analyze question. You need to look at each choice presented, break it down into its parts and see if it matches the criteria to count as communication. This is a check all that apply question, which means that there can be more than one correct answer. Examine each choice and see if it fulfills the definition of communication. Gather Content: What do you already know about what behavior qualifies as communication? What other information is related to the question? This question is from the section of the textbook that discusses what defines animal communication and different modes of animal communication. All of the choices are examples of behaviors, you need to select the behaviors that are example of communication. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? There are five choices presented and all but one are examples of animal communication. In the first example a bird gives an alarm call but no other birds hears the call, thus no communication took place. Reflection on Process:
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to select all of the correct choices? You needed to extract the information from the graph and pick the correct choice. The key to this question is the realization that communication needs at least one individual to receive the message. 7) [A, C, D, E] 8) [B, C, G]
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Clarify question: What is the key concept addressed by the question? The question asks about the feeding behavior in herring gulls. What type of thinking is required? This is an apply question, you will need to apply the knowledge you have about how behavioral responses are produced and then apply it to the situation with the herring gull. This question has 3 correct answers Gather Content: What do you already know about feeding behaviors? What other information is related to the question? This question comes from the section of the textbook that deals with the relationship between stimuli and fixed responses. You have 3 parts of identify: the stimulus, the mechanism that produces the behavior, and the behavior itself. What stimulates the chick? How does the chick produce the behavior? What is the behavioral response performed by the chick? Choose Answer: Given what you now know, what information is most likely to produce the correct answer? The spot is the stimulus, the neural circuit is the innate releasing mechanism, and the pecking is the fixed action pattern. Reflection on Process: Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to determine the correct answers? You had to apply concepts of behavior to a situation and pick out the components of that behavior. 9) [B, C, F, I, J]
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Clarify question: What is the key concept addressed by the question? The question asks about the underlying factors effecting various behaviors in fruit flies. What type of thinking is required? This is an analyze question. You have to analyze the various factors that might play a role in the mating dance of male fruit flies. Physiological factors are going to allow the fly to perform the dance. Evolutionary factors help to determine the adaptive value of the dance. This is a check all that apply question, all of the choices that are directly involved in performing the behaviors are correct choices. Gather Content: What do you already know about physiological and evolutionary factors underlying a behavior? What other information is related to the question? In this question you need to select all of the physiological factors from the choices given. The physiological factors are parts of the fly the allow it to perform the dance. Evolutionary forces certainly play a role in selecting for certain behaviors, but they are not physiological factors that allow for the performance of the specific behavior. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Brain circuits, hormones, sensory neurons, visual system, and wings are all involved in the physiological factors that are involved in the male Version 1
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mating dance. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Did you get the question right? You had to look over all the choices and pick out all that are physiological factors that influence behavior. 10) [A, B, C]
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Clarify question: What is the key concept addressed by the question? Identifying evidence for the connections between a behavior and the genes involved. What type of thinking is required? This is an analyze question. You are being presenting the 4 different studies and you need to select the ones that are linking genes and behavior. You need to read each choice and see what the genes are doing and then determine if the answer choice is an example of a gene modification to an animal’s behavior. There is more than one correct answer. Gather Content: What do you already know about the genetics that underlies a behavior? What other information is related to the question? This question comes from the section of the textbook that discusses scientific studies that have shown the links between animal behavior and the genes that underlie the behavior. Learning, locomotion, and aggression are all examples of behavior. The physical size of an organism is not a behavior. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? All are examples of behaviors except for the twin study that demonstrates the heritability of height. Reflection on Process:
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to select all of the correct choices? You had to look over all the choices and pick out all of the ones that demonstrated the link between genes and behavior. 11) [D, E, G]
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Clarify question: What is the key concept addressed by the question? How playing video games relates to the behavior studied using a Skinner box. What type of thinking is required? This is an analyze question. You are being asked to compare the act of playing a video game with the operant conditioning that occurs when a rat is placed in a Skinner box. In this question you must select all of the correct answers. Gather Content: What do you already know about what was studied with the Skinner box and what behaviors are exhibited when playing video games? What other information is related to the question? This question comes from the section of the textbook that discusses the different types of learning. You are being asked to look at all of the choices and select the ones that a human playing a video game and a rat in a Skinner box have in common.Skinner's operant conditioning chamber was a box with a lever that could be pushed to produce a reward, and has become synonymous with activities that involved repeated actions and rewards, with voluntary behavior by the subject. It differs from classical or Pavlovian conditioning, which involves passive or involuntary behavior by the subject (e.g., dog salivating) in response to a conditioned stimulus (e.g., a bell) that has been associated with a reward (e.g., food). Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Version 1
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Voluntary behavior, repeated actions, and rapid feedback are all components of learning that humans playing video games and rat in a Skinner box have in common. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to select all of the correct answers? The key to answering this question was to take operation of a skinner box and break it in to its parts. Then you needed to identify the parts of the interaction in the Skinner box that were similar to what happens when playing a video game. 12) [B, C, E, G, H, J]
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Clarify question: What is the key concept addressed by the question? What would be the requirements for designing a experiment studying animal cognition. What type of thinking is required? This is an apply question. You need to take what you know about animal cognition and apply it to this situation. This is a check all that apply type of question; there are multiple correct answers. All of the choices are parts of an experiment. You need to select all of the choices that would be useful in designing an experiment that test animal cognition. Gather Content: What do you already know about animal cognition experiments? What other information is related to the question? Counting individuals, determining hormones levels, analyzing fixed action patterns, and measuring the response to key stimuli are all valid experimental objectives, but they do not provide any insight into an animal’s cognitive ability. All of the other choices are good experimental design characteristics and will help assess the level of cognitive ability in the research animals. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? All of the other choices are good experimental design characteristics and will help assess the level of cognitive ability in the research animals. Reflection on Process:
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to select all of the correct choices? The key to this apply question is to look at the choices are see if the information they provide will help measure an animal's cognitive ability. 13) [B, C, F]
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Clarify question: What is the key concept addressed by the question? How to study sexual selection behaviors in swordtail fish. What type of thinking is required? This is an analyze question, you need to break down each answer into its components and decide which are the best choices. You are being asking to choose between a series of experiments concerning mate choice is swordtails. There are 3 correct answers in the set. Gather Content: What do you already know about sexual selection behaviors? What other information is related to the question? This question comes from the section of the textbook that discusses the nature of signals and mate choice. All of the choices would provide some data, but only 3 of the choices deal with the length of the swordtail. The length of a male swordtail is the main visual cue that females use when selecting mates. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Lengthening tails, shortening tails, or using models with varying tail lengths would all be experiments that would provide information about the visual cue that female use to pick mates. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? Were you able to select the 3 correct choices? The key to this question is to understand that female swordtails use the visual cue of tail length to pick mates. 14) [A, C, D, F]
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Clarify question: What is the key concept addressed by the question? The results when a female isn't maximizing fitness with mate choice. What type of thinking is required? This is an analyze question, you need to break down all of the given outcomes and pick the best ones. You need to select which of these outcomes would result from a female not being careful when picking a mate. The goal of mate choice is to pick the highest quality mate, thus maximizing fitness. Gather Content: What do you already know about mate choice and fitness? What other information is related to the question? This question comes from the section of the textbook that discusses the role of courtship. Picking the best male gives the female the best chances of producing high quality offspring with higher fitness than other potential offspring. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Anything that reduces her fitness or the fitness of her offspring is a potential downfall of not being picky when it comes to mate choice. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? The key to this analyze question is to understand the link between mate Version 1
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choice and fitness.Her lack of male selection may effect her reproductive fitness. 15) [A, C, E]
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Clarify question: What is the key concept addressed by the question? The waggle dance behavior in bees and what sensory inputs are used. What type of thinking is required? This is an analyze question, you are given several different sensory information modalities used by bees and are being asked to choose the ones that will allow the bee to get information from the waggle dance. Gather Content: What do you already know about the waggle dance in bees? What other information is related to the question? This question comes from the section of the textbook that discusses the role of the waggle dance in honeybee communication. All of the choices are sensory modalities, but not all of them are used to gather information from the dance. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? The dance produces signals via sight, sounds, and chemical information. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Did you get the question right? The key to this question is to figure out how the dance provides information to the other bees. 16) [B, E, F] Version 1
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17) [B, C, E] 18) [A, B, D]
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Clarify question: What is the key concept addressed by the question? The advantages of living in a group and which examples exhibit those. What type of thinking is required? This is an analyze question, so you will need to break the choices down into their components to get the correct answer. This question gives you several scenarios and you are being asked to identify which ones represent an advantage to group living. This is a check all that apply questions, there are multiple correct answers. Gather Content: What do you already know about the advantages of group living? What other information is related to the question? Everything is a trade-off, group living has advantages and disadvantages. You need to look at each choice and determine if it represents an advantage or a disadvantage. Disease spreads much quicker in large groups of individuals and large groups of individuals will need more food and other resources. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? More efficient predation, more protection from predators, and the construction of large scale structures are certainly advantages. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? Did you select all of the correct answers? Understanding that living in groups is a trade-off is the key to this question. 19) [A, B, C]
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Clarify question: What is the key concept addressed by the question? Comparing group living in naked mole rats and insects. What type of thinking is required? This is an analyze question, you will need to break the choices down into their components to get the correct answer. In this question you are being asked to select all of the similarities between naked mole rats and social insects. There are multiple correct answers. Gather Content: What do you already know about group living in different animal groups? What other information is related to the question? These 2 types of societies have lots of similarities but they aren’t identical. The organizations are quite similar but the underlying genetics are quite different. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? The features responsible for the organization of the colony are the similarities. Reflection: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Did you select all of the correct answers? The key is to see the difference between how the organization of the colony and the genes Version 1
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that produced those behaviors are different. 20) B 21) C 22) A 23) C 24) D 25) A 26) C 27) D 28) B 29) E 30) E 31) A 32) B 33) D 34) A 35) B 36) D 37) C 38) B 39) C 40) E 41) C 42) C 43) B 44) B 45) B 46) A 47) B
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Clarify question: What is the key concept addressed by the question? This question requires the interpretation of a graph. The data on the graph show the relationship between intensity of material behavior and the presence/absence of a particular allele. What type of thinking is required? This is an evaluation question, you are being asked to look at the choices being presented and pick the best one.
Gather Content: What do you already know about the relationship between maternal behavior and a particular allele? What other information is related to the question? What do you know about this situation? Genes can control behaviors. Providing maternal care to offspring can increase their survivability, increasing their fitness. Alleles are forms of a gene. Which group has the highest level of maternal behaviors?
Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Mice with fosB allele spend much longer crouching over their infants, and retrieve a great proportion of their pups when they are separated from them. These behaviors demonstrate maternal care provided to the infants. The choice that says “greater than the maternal care given by female mice without the fosB allele” is the correct answer.
Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to select the correct answer? You were being asked to look at a graph, evaluate a series of statements and pick the choice that best fit the graph. This question is linked to the section in the textbook that describes the relationship between genes and behavior. In this example the presence of one allele was strongly associated with an increase in the intensity of maternal care, providing evidence for a link between the observed behavior (maternal care) and the genes that underlie that behavior.
48) B Version 1
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49) D 50) E 51) C 52) C 53) B 54) A 55) B 56) A 57) C 58) B
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Clarify question: What is the key concept addressed by the question? This graph show three sets of data: size of mussels, energy content relative to the size of the mussel, and the number and size of mussels that a crab consumes per day. What type of thinking is required? This is an evaluate question. You are being asked to break down the information into individual components and then pick the best interpretation of the data. Gather Content: What do you already know about optimal foraging behaviors? What other information is related to the question? This question is linked to the section of the textbook that discusses optimal foraging behaviors. Optimal foraging essentially means getting the most bang for your buck. This data set certainly shows that mussels eat crabs, but which is the BEST interpretation of the graph? Is there a pattern in the size that is selected or are the crabs eating mussels randomly? Do the largest mussels provide the most nutrition to the crab? Choose Answer: Given what you now know, what information is most likely to produce the correct answer? The peak of the histogram and the line graph match pretty well. That shows that the crabs are not just randomly eating mussels, but are preferentially selecting the mussels that provide the highest energy gain. A crab that preferentially eats the most energy rich mussels will have to spend less time eating and will have optimized their foraging. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to pick the correct answer? You needed to extract the information from the graph, and pick the best interpretation of the data from the choices presented. The concept here is optimal foraging; the crab was trying to get the most reward for the least amount of effort.
59) C 60) A
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Clarify question: What is the key concept addressed by the question?. The question is asking what type of behavior is involved in flash patterning in fireflies. This is an apply level question. You are being presented with a situation. Using what you know about the different behavioral terminology, you can explain what is happening in this situation. Gather Content: What do you already know about animal behavior? What other information is related to the question? This question comes from the section of the textbook that covers the basics of animal behaviors. A stimulus is recognized by an individual, the innate releasing mechanism in the individual produces a specific behavior (the fixed action pattern). In this case the female firefly is looking for a mate. A male firefly sees the signal, and the signal triggers a response from the male. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? In this scenario, the pattern of flashes produces the behavioral response in the male. Thus the flashes from the female are the key stimulus (sign stimulus) that the male recognizes. Reflection on Process: Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to select the correct answer? You need to take what you know about animal behavior and apply it to this situation to come up with the answer. You needed to breakdown the series of behaviors and look at each part. 61) B
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Clarify question: What is the key concept addressed by the question? The question asks type of behavior is being exhibited by the moth. What type of thinking is required? This is an apply level question. You are being presented with a situation. Using what you know about the different behavioral terminology, you can explain what is happening in this situation. Gather Content: What do you already know about animal behavior patterns? What other information is related to the question? This question comes from the section of the textbook that covers the basics of animal behaviors. A stimulus is recognized by an individual, the innate releasing mechanism in the individual produces a specific behavior (the fixed action pattern). In this case the moth hears an ultrasonic chirp from a bat and then reacts with a standardized behavior. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? In this scenario the chirps are a sign stimulus, this triggers a reaction in the moth. The moth instinctually responds with a rapid vertical dive. This behavior is performed in exactly the same way every time the sign stimulus is received. Thus the dive is a fixed action pattern. Reflection on Process: Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Did you select the correct answer? You need to take what you know about animal behavior and apply it to this situation to come up with the answer. You needed to breakdown the series of behaviors and look at each part. 62) C
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Clarify question: What is the key concept addressed by the question? The question is about identifying the type of behavior exhibited by male stickleback fish. What type of thinking is required? This is an apply level question. You are being presented with a situation. Using what you know about the different behavioral terminology, you can explain what is happening in this situation. Gather Content: What do you already know about behavior in stickleback fish? What other information is related to the question? This question comes from the section of the textbook that covers the basics of animal behaviors. A stimulus is recognized by an individual, a neural mechanism in the individual produces a specific behavior (the fixed action pattern). What is the linkage between the stimulus (red stripes) and the response (aggressive behavior towards the object)? Choose Answer: Given what you now know, what information is most likely to produce the correct answer? The innate releasing mechanism is the internal neural circuit that links the stimulus to the behavior. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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Did you pick the correct choice? You need to take what you know about animal behavior and apply it to this situation to come up with the answer. You needed to breakdown the series of behaviors and look at each part. 63) E
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Clarify question: What is the key concept addressed by the question? The question is about feeding behaviors in herring gulls. What type of thinking is required? This is an apply level question. You are being presented with a situation. Using what you know about the different behavioral terminology, you can explain the gull’s behaviors. Gather Content: What do you already know about animal behaviors, specifically feeding behaviors in herring gulls? What other information is related to the question? This question comes from the section of the textbook that covers the basics of animal behaviors. There are two animals that are involved in this interaction. The chick sees the red spot on the parent’s bill (stimulus), it pecks at the spot (fixed action pattern in response to the stimulus). The pecking acts as a stimulus to the parent; the parent responds (fixed action pattern) buy regurgitating food. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? This series of linked behaviors is a stimulus-response chain. Reflection on Process: Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to get the correct answer? You needed to take what you know about animal behavior and apply it to this situation to come up with the answer. You needed to breakdown the series of behaviors and look at each part. 64) B
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Clarify question: What is the key concept addressed by the question? The question is about the type of learning exhibited in a puppy. What type of thinking is required? This is an apply level question. You are being presented with a situation. Using what you know about the different behavioral terminology, you can explain why the puppy loses interest in the food bowl. Gather Content: What do you already know about types of learning behaviors? What other information is related to the question? This question comes from the section of the textbook that covers the types of learning. In this question you are being asked to apply what you know about the different types of behaviors to the situation of the dog and the food bowl. There is no reward or punishment in this situation, and the food bowl is always empty. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? The initial few presentations of the bowl elicit a reaction, but after multiple presentations the dog stops reacting because there is never anything in the bowl. This is an example of habituation. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? Did you select the correct answer? You needed to take what you know about animal behavior and apply it to this situation to come up with the answer. You needed to breakdown the series of behaviors and look at each part. 65) D
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Clarify question: What is the key concept addressed by the question? The question is asking about the waggle dance exhibited by bees. What type of thinking is required? This is an apply level question. You are being presented with a situation. Using what you know about the bee communication you can explain what information the bee is try to covey via the dance. Gather Content: What do you already know about the waggle dance in bees? What other information is related to the question? This question comes from the section of the textbook that discusses the details of bee communication. The bee dance conveys the information about the source of the pollen relative to the position of the sun. If a bee dances along the vertical axis it means the flowers are towards the sun. Dances to the right signal a deflection to the right relative to the sun and dances to the left mean a left deflection. If the sun is due West and the flowers are due North, then what is difference in degree from West to North? Choose Answer: Given what you now know, what information is most likely to produce the correct answer? If you faced West, due North would be 90 degrees to your right. Reflection on Process:
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Did you get the question right? You needed to take what you know about bee dances and apply it to this situation to come up with the answer. You also needed to figure out what information is relevant and what is not. 66) D
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Clarify question: What is the key concept addressed by the question? This question is about family relationships and kin selection. What type of thinking is required? This is an apply question. You are being presented with a situation. You need to apply what you know about inclusive fitness to determine which of the choices is correct. Gather Content: What do you already know about kin selection? What other information is related to the question? This question comes from the section of the textbook that discusses kin selection and inclusive fitness. Inclusive fitness is the concept that copies of your genes reside with yourself and your close relatives. A full sibling has on average 50% of the genes that you have. This is why you look like your brother or sister. If you were killed before reproducing then 0% of your genes would be passed on. However if your death saved the lives of two brothers and they reproduced then 100% of your genes would be passed on (50% from each brother). A niece or nephew is a mixture of your full sibling (50% of your genes) and an unrelated individual (0% of your genes). That means that a niece or nephew shares 25% of your genes. A son or daughter is a mixture of your genes (100%) and an unrelated individual (0%) thus a son or daughter shares 50% of your genes. Uncles share 25% (half of the genes from one of your parents), grandchildren share 25% (half of your child’s half), and cousins share 12.5% (half of your aunt or uncle and an unrelated individual)
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Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Knowing this, the question becomes a math problem 1 son or daughter = 50% 4 cousins = 50% 3 uncles = 75% 2 nephews (50%) plus 1 son or daughter (50%) = 100% 2 grandchildren = 50% Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to select the correct choice? You needed to take what you know about inclusive fitness and calculate the different percentages for each combination. The one that equals 100% accounts for all of your genes. 67) B 68) D
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Clarify question: What is the key concept addressed by the question? The question asks about ultimate and proximate causes of a behavior in fleas. What type of thinking is required? This is an evaluate question. You need to read the description of the flea behavior, read all of the choices and pick which one is the best. More than one can be correct or at least partially correct; you need to pick the choice that is the best explanation for the flea’s behavior. Gather Content: What do you already know about the differences in the proximate and ultimate causes of a behavior? What other information is related to the question? Proximate causes are physiological series of events that produce the particular behavior in question. Ultimate causes are the adaptive benefits that allowed natural selection of favor the particular behavior. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? The first 2 choices only deal with one of the causes. Of the two remaining choices one confuses proximate and ultimate. Only one choice address both causes of behaviors and correctly categorizes them. Reflection on Process:
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? This was an evaluate question. You are being asked to make a judgement between multiple answers that are at least partially correct. You needed to pick the best choice. 69) D
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Clarify question: What is the key concept addressed by the question? The sensory structures that would help the beetle find the most advantageous spot to lay its eggs. What type of thinking is required? This is an apply question. You need to look at the 4 choices, break them down into their constituents, and see which one would be the most useful for seeking out freshly burned wood. Gather Content: What do you already know about sensory systems involved with behavior? What other information is related to the question? This question comes from the section of the textbook that deals with the structure of neural circuits and how they are linked to animal behavior. The choices deal with the speed of signals, the processing of signals, and the sensory systems. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Sensory structures are what will allow the beetle to detect burned wood. The beetle must be able to detect the burned wood before laying eggs on it. Reflection on Process: Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to select the correct answer choice? You had to look over all the choices and pick out all of the ones that are involved in the detection of burned wood. 70) C 71) B
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Clarify question: What is the key concept addressed by the question? Understanding the mating behaviors of prairie and montane voles and how they relate to different species. What type of thinking is required? This is an analyze question. You need to break down the 4 statements into the components and determine which one is correct. Gather Content: What do you already know about the hormones involved in mating in the species of voles? What other information is related to the question? This question comes from the section of the textbook that discusses the role of genes in pair bonding. You need to identify the functions of the hormones and their receptors. Do vasopressin and oxytocin receptors increase monogamy or promiscuity? Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Vasopressin and oxytocin receptors are associated with monogamy. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Did you come up with the correct answer? You had to look over all the choice and pick out all of the ones that demonstrated the link between Version 1
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the presence of hormone receptors and the associated behaviors. 72) D 73) C
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Clarify question: What is the key concept addressed by the question? The learning process that is used by the bear. What type of thinking is required? This is an apply question. You need to take what you know about the different learning mechanisms and apply it to the situation of the bear raiding garbage cans. Gather Content: What do you already know about different learning mechanisms? What other information is related to the question? This question comes from the section of the textbook that discusses the different types of learning. Habitation involves no reward or punishment, classical conditioning involves the association between a passive behavior and stimulus. Operant condition involves the learning of new behaviors using reward and punishment. Air conditioning makes the research lab a comfortable place to work. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? This is an example of operant conditioning; the bear learns to tear open garbage cans because it gets rewarded with food. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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Did you get the correct answer? You needed to take what you know about the different types of learning and apply it to the situation of the bear and the garbage. 74) D
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Clarify question: What is the key concept addressed by the question? The key concept is learning preparedness. What type of thinking is required? This is an evaluate question. You are given 4 different experimental designs. All are valid experiments but your task is to identify which would be the best to provide insight about how hamsters are predisposed to learn. Gather Content: What do you already know about learning preparedness? What other information is related to the question? This question comes from the section of the textbook that discusses the different types of learning. All of the experimental designs will produce data. The goal of the study is to identify which hamster instinctual behaviors are going to be most compatible with conditioning. Only one of the studies is designed to provide information about which sensory input are most important to a hamster. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? The study presenting hamsters with different types of sensory information is going to assess what the learning preparedness of a hamster is. Reflection on Process: Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Did you choose the correct answer? All of the choices where valid experimental designs, but only one was the best choice for providing the information needed. 75) A
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Clarify question: What is the key concept addressed by the question? You are trying to find the linkage between specific behaviors and the structure of the brain that produces those behaviors. What type of thinking is required? This is an evaluate question, you are being asked to make a judgement between all of the possible choices. You are trying to figure out what characteristics you would expect to find in the brains of birds that have completely different lifestyles. Gather Content: What do you already know about brain characteristics associated with different behaviors? What other information is related to the question? This question comes from the section of the textbook that discuss learning preparedness. Different species of animals will be predisposed to learning certain types of behaviors. The main task in this question is to link the brain region with its function. The hippocampus is involved in spatial memory, the hypothalamus regulates circadian rhythms, the olfactory system is used to process odors and the visual system is linked to vision. A predatory birds needs very sharp eyesight to see prey from a distance and to be able to catch prey inflight. A bird that stores food for later retrieval must be able to remember where the food is located. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Long term food storage requires very good spatial memory, and hunting down prey while flying requires excellent vision. Thus a nut-hiding Version 1
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species would most likely possess a larger hippocampus and a predatory bird would most likely have more brain tissue devoted to visual processing. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Did you choose the correct answer? The key to this evaluation question was to link the brain area with its associated function and then to determine which brain function would be most useful for the particular type of bird. 76) B
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Clarify question: What is the key concept addressed by the question? Possible explanation for the behavior seen in a parrot. What type of thinking is required? This is an evaluate question. You are being presented with a situation and you are being asked to select the best possible explanation for the behavior of the parrot. Gather Content: What do you already know about behaviors in an adult parrot based on how it was raised? What other information is related to the question? This question comes from the section of the textbook that discusses the role of imprinting. Imprinting occurs during an early critical period in the life of an animal. If the imprinting does not occur within the critical period the animals may never be able to fully perform certain behaviors. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? In the wild, parrots can fly just as well as any other species of bird. This clumsy parrot may never be able to fly because it failed to learn the basics of flight during its early life. The neural patterns weren’t fully developed and thus the parrot may never be able to fly well. Reflection on Process: Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to select the correct choice? The key to this evaluation question was to associate the clumsy fling of the parrot with the lack of neural development during the critical period for flight. 77) D
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Clarify question: What is the key concept addressed by the question? The goal of the question is to determine when the critical period for imprinting occurs. What type of thinking is required? This is an analyze question. You need to break each of the choices down into its components to see if it matches the data from the table. The data from the table shows the age of the chick and when imprinting was observed. Gather Content: What do you already know about imprinting? What other information is related to the question? Imprinting occurs during an early critical period in the life of an animal. If the imprinting does not occur within the critical period then the animals will never be able to imprint on its mother. Paring a chick with a foster mother between 0-3 days after hatching lead to successful imprinting whereas chicks that were paired with foster mothers 8-11 days after hatching did not successfully imprint on the foster mother. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? The data show that the critical period ends somewhere between days 38, the data does not give any information about when the imprint period begins. It may begin within minutes after hatching or later during the first day. Reflection on Process:
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Did you get the questions right? The key to this question is to interpret the data presented on the table and see what choice best matches the data. 78) A
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Clarify question: What is the key concept addressed by the question? Looking at what humans need in light of the Harlow experiment with rhesus monkeys. What type of thinking is required? This is an evaluate question, you are making a judgement as to which choice is the best possible answer. You will need to pick the choice that takes the results of Harlow’s experiments with rhesus monkeys and applies it to human babies. Gather Content: What do you already know about Harlow's experimental results? What other information is related to the question? Harlow’s experiment with baby rhesus monkeys demonstrated that baby monkeys need to have physical contact with their mothers in order to develop normally. Most of these choices would provide a more comforting environment for an infant, but only one of these would make it easier for mothers to provide their infants with more opportunities for physical contact with their mothers. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Comfortable chairs would allow for more tactile stimulation between mothers and infants. Reflection on Process: Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Did you get the question right? The key to this evaluate question was understand the implications of Harlow’s research on the influence of tactile stimulation and the development of the infant. Then the challenge was to evaluate the choices and determine which one would be the best for promoting increased contact between mother and infant. 79) A
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Clarify question: What is the key concept addressed by the question? Knowing what environment will be important for the males to learn mating behaviors. What type of thinking is required? This is an evaluate question. You will need to make a judgement as to which of the choices is the best possible answer. You are being presented with 4 experimental designs. You need to examine all 4 choices and pick the best experimental design. Gather Content: What do you already know about mating behaviors in male birds? What other information is related to the question? You need to use what you know about the interaction of instinct and learning in songbirds to help you pick the correct experimental design. Male songbirds have an innate ability to produce songs but they cannot sing their mating song well without listening to the correct song. All of the approaches are valid but only one of them is going to be helpful in making the young males perfect their mating songs. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Male birds usually need to hear their songs during development and so it will be important to expose the males to a mentor male bird singing their species' song during the critical period.. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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Were you able to select the correct answer? The key is to understand that that although male song birds have some innate ability to perform the mating song, they need to be exposed to the song during the critical period in order for them to perfect it. 80) C
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Clarify question: What is the key concept addressed by the question? Understanding what can explain the feeding behavior of hummingbirds, that are migratory birds. What type of thinking is required? In this question you are being asked to analyze the situation of the disappearing hummingbirds and come up with a recommendation for your friend. Gathering Content: What do you already know about feeding behaviors in birds? What other information is related to the question? This question comes from the section of textbook that focuses on migratory behavior. Hummingbirds do migrate during the year. Only one of the choices address migrations, the other options might be able to attract hummingbirds to a feeder if the hummingbirds remain in the area. None of the other strategies would work if the hummingbirds have already migrated away. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Migrations are long distance 2-way movements. Typical bird migrations in North America involve flying South during the autumn and then return North in the spring. If a bunch of hummingbirds visit the feeders in the spring and then disappear then they will probably move back through the area in the fall during the reverse leg of the migration Reflection on Process: Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to pick the correct choice? The key to this apply question is to understand that migrations are 2-way, long distance mass movements of species. 81) A 82) C 83) D Natural selection can only select for behaviors that have some genetic basis. The special display behavior of a male peacock is an example of a behavior that was naturally selected, but is only present in the male, probably increases rather than reduces predation, and is not seen in other related species. 84) C
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Clarify question: What is the key concept addressed by the question? Determining the advantages of a male hummingbird's highly visible plumage. What type of thinking is required? This is an analyze question, all of the choices are potential explanations for the presence of a bright iridescent path on the hummingbird’s plumage. Only one of the choices is correct. Gather Content: What do you already know about the tradeoff of being visible to potential mates and predators? What other information is related to the question? The main goal of any organism is to survive and pass on its genes. Something that may seem maladaptive (having bright patches of feather) may have an advantage that outweighs the costs. The key to this question is to recognize the concept of an evolutionary trade-off. Only one of the choices explains the presence of a gorget in the context of an evolutionary trade-off. Behaviors that decrease overall fitness are very rapidly selected out of a population. Hummingbirds certainly face predation and many predators use vision to detect prey. Answer: Given what you now know, what information is most likely to produce the correct answer? The gorget helps the hummingbird maintain a specific territory. By monopolizing a territory the male hummingbird can have greater access to females, increasing his chance of passing on his genes.
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Reflection: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to get the correct answer? Recognizing and understand the concept of an evolutionary trade-off is the key to this question. 85) C
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Clarify question: What is the key concept addressed by the question? Mate selection and parental investment involved in this species where the male and female roles are reversed. What type of thinking is required? This is an analyze question, you will need to break down the choices into their components to find the correct answer. You are given choices for female breeding behaviors and are being asked to pick the best one. Gather Content: What do you already know about traditional roles of mate selection and parental investments? What other information is related to the question? The key is to recognize the role of parental investment in raising offspring. Normally male animals provide less care, female choose the best quality male they can find and then do most of the parental care (if any parental care is being provided). The situation with these birds is reversed. Females still produce eggs and males still produce sperm, the behaviors are different but the sexes are the same. A single male could not possible maintain a large number of females if her is providing all of the parental care. If females are going to compete for males then the expectation is that the females will be the brightly colored sex (that is the case with these birds). Choose Answer: Given what you now know, what information is most likely to produce the correct answer? The correct choice is that females compete and males choose the females. Version 1
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Reflection: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Did you select the correct answer? Recognizing that the roles are reversed in this species is the key of finding the answer to this question. 86) A 87) D
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Clarify question: What is the key concept addressed by the question? Comparing altruism is humans versus vampire bats. What type of thinking is required? This is an analyze question, you will need to break the answers down into their components. You are being asked to examine the choices and pick the one that shows a commonality between humans and vampire bats. Gather Content: What do you already know about altruism? What other information is related to the question? Humans and vampire bats are both mammals but are very different from each other. Both do live in large groups and both practice altruistic behaviors. Altruistic behaviors are behaviors that increase another individual’s fitness at the cost of one's own fitness. Vampire bats go out at night and feed on blood, they have been observed to feed other bats that are not related to them. They will feed other bats, but the behavior is a give and take. Bats only feed other bats that have fed them. Haplodiploidy is not relevant here, humans and bats are diploid. Chiroptera is the group that contains the bats, humans are primates. The feeding is not based on kinship; it is based on concept of reciprocity. If you scratch my back, I’ll scratch yours. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Humans and bats show reciprocal altruism.
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Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to select the correct answer? The key here is to recognize the different explanations for altruistic behavior. 88) C
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Clarify question: What is the key concept addressed by the question? Determining the role of genes in kin selection. What type of thinking is required? This is an analyze question, you will need to break all of the answers down into their components to find the correct answer. This question is asking about the linkage between genes and kin selection. Gather Content: What do you already know about the genetic basis of kin selection? What other information is related to the question? Kin selection occurs when an animal does things that increase the fitness of relatives, these behaviors may even put the animal at increased risk of danger. The most important thing is to be able to recognize your kin for unrelated individuals. Genes that promote the recognition of kin are going to be very useful for promoting kin selection. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Of the choices, MHC genes are the most useful in kin selection. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Did you get the question right? The key to this question is to understand the concept of kin selection and how genes can influence it. Version 1
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89) A African weaver birds, which construct nests from vegetation, provide an excellent example of the relationship between ecology and social organization. Their roughly 90 species can be divided according to the type of social group they form. One group of species lives in the forest and builds camouflaged, solitary nests. Males and females are monogamous; they forage for insects to feed their young. The second group of species nests in colonies in trees on the savanna. They are polygynous and feed in flocks on seeds. The feeding and nesting habits of these two groups of species are correlated with their mating systems. In the forest, insects are hard to find, and both parents must cooperate in feeding the young. The camouflaged nests do not call the attention of predators to their brood. On the open savanna, building a hidden nest is not an option. Rather, savanna-dwelling weaver birds protect their young from predators by nesting in trees, which are not very abundant. This shortage of safe nest sites means that birds must nest together in colonies. Because seeds occur abundantly, a female can acquire all the food needed to rear young without a male’s help. The male, free from the duties of parenting, spends his time courting many females—a polygynous mating system. 90) A 91) A 92) Section Break 92.1) A 92.2) C 92.3) B 92.4) E 92.5) D 93) Section Break 93.1) [A, C, E, G, H] Version 1
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Clarify question: What is the key concept addressed by the question? The question is asking about the proximate basis of an unusual behavior in a species of moth. What type of thinking is required? This is an analyze question. You need to read the description of the moth behavior, break them down into their components, and figure out which of the choices would be involved in the proximate cause of behaviors. This is a check all that apply question, there are multiple correct answers. Gather Content: What do you already know about proximate causes of a behavior? What other information is related to the question? Proximate causes are physiological series of events that produce the particular behavior in question. Which of the choices are involved in the physiological causes of the moth’s diving behavior? Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Brain structure, hormones, physiology, sensory organs, and wing muscles are involved in producing the behavior. The other choices are unrelated or are involved in the ultimate causes of the behavior. Reflection on Process:
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to determine the correct answer? You needed to consider the how each of the choices influences the diving behavior and determine if it is part of the proximate cause or the ultimate cause of the behavior. 93.2) [B, D, F]
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Clarify question: What is the key concept addressed by the question? The question asks about an ultimate cause of an unusual behavior in a species of moth. What type of thinking is required? This is an analyze question. You need to read the description of the moth behavior and figure out which of the choices would be involved in ultimate cause of behaviors. This is a check all that apply question, there are multiple correct answers. Gather Content: What do you already know about ultimate causes of a behavior? What other information is related to the question? Ultimate causes are the adaptive benefits that allowed natural selection of favor the particular behavior. Which of the choices are involved in the ultimate causes of the moth’s diving behavior? Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Brain structure, hormones, physiology, sensory organs, and wing muscles are involved in producing the behavior. Flying behavior in related species, mating behavior, and predation are all involved in the ultimate cause of the moth’s diving behavior. Reflection on Process:
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Did you get the question right? You needed to consider the how each of the choices influences the diving behavior and determine if it is part of the proximate cause or the ultimate cause of the behavior.
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Chapter 54 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) True or False: An r-selected species is more likely to become an invasive pest than a Kselected species. ⊚ true ⊚ false
CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 2) Which of the following describe density-dependent factors? A) They act toregulate population growth. B) They are especially important in K-selected populations. C) They can affect growth rates but not population size. D) They can affect birth rates or deathrates. E) They do notinvolve biological interactions. F) One example would be intraspecific competition for resources.
3)
What are characteristics of r-selected populations? (Check all that apply.) A) early age of firstreproduction B) late age of firstreproduction C) small broodsize D) large broodsize E) little or noparental care F) extensive parentalcare G) short generationtime H) long generationtime I) type Isurvivorship curves J) type III survivorship curves
4) Which of the following apply to the demography of human populations today? (Check all that apply.)
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A) Our ecologicalfootprint is decreasing. B) We are using distributed resources disproportionately—less than 20% of us use over 80% of the energy. C) We have plenty of resources stilluntouched. D) We use almosthalf of the Earth's land. E) We use over halfof all renewable fresh water sources.
5) Which of the following are environmental factors that determine where an organism can live? (Check all that apply.) A) intraspecificcompetition B) predation C) preyavailability D) soil type E) sunlight F) temperature G) water
6)
Which of the following describe source-sink metapopulations?
A) Sink populationsnear source populations are less likely to go extinct. B) Sink populationswithout access to immigrants from source populations are less likely to goextinct. C) Source populationsusually occupy better habitats. D) Source populationsare less likely to go extinct. E) The emigration rate from sourcepopulations exceeds that from sink populations.
7) An underwater volcano has erupted, and as the lava cools a new island has formed. Which types of animal species are likely to be among the first to colonize the island? (Check all that apply)
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A) annelids B) bats C) birds D) insects E) snails F) snakes G) tapirs H) tortoises
8) A population of squirrels is in a phase of exponential growth. Which events would act to slow this growth? (Check all that apply) A) a forest fire thatdestroys habitat B) logging of nuttrees C) growth of thehawk population D) heavy rainfall,resulting in larger seed and nut harvest E) increasedpopulation that is outstripping food supply F) less competitionfrom a diminished population of ground squirrels
9) A developing nation with a rapidly increasing population is reaching its carrying capacity. What change(s) could allow it to increase its carrying capacity? (Check all that apply) A) a cultural shiftto eating less meat B) education forwomen C) greater yieldfrom agricultural crops D) increasedavailability of birth control E) water treatment plants
10) What circumstances allowed SARS-CoV-2 to cause a global pandemic? Check all that apply.
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MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 11) Populations of endotherms that live in colder climates tend to have shorter ears and limbs than populations of the same species in warm climates. This is called ____________ Rule. A) Allen's B) the K-Selected C) the r-Selected D) Edward's
12) The rate at which a population of a given species will increase when no limits are placed on its rate of growth is called its A) maximum growth. B) carrying capacity. C) biotic potential. D) optimal growth.
13) The size at which a population stabilizes in a particular place is defined as the __________ for that species. A) growth potential B) optimum C) range D) carrying capacity
14) Life history adaptations of ___________ populations are characterized by an early age of first reproduction and short maturation time and life span. A) r-selected B) K-selected
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15) Species that have a delayed reproductive stage, are competing for limited resources, and have smaller numbers of slowly maturing large offspring show ________________ adaptations. A) K-selected B) r-selected
16) The statistical study of populations including sex ratio, age structure, and predicting growth rates is called _________. A) ethology B) demography C) population genetics D) biometrics
17)
A group of population members all of the same age is called a ________. A) deme B) species C) cohort D) tribe
18) Organisms such as lizards that need to maintain body temperature through external means do so by A) shivering to produce heat. B) sunbathing. C) swimming in geothermal pools. D) running frequently to warm up. E) eating large meals to provide calories for heat production.
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19) What is the life history adaptation called where organisms produce offspring several times over many seasons? A) semelparity B) iteroparity C) biparity D) polyparity E) alloparity
20) Effects that are dependent on the size of the population and regulate the growth of populations are called ___________ effects. A) K-related B) density-independent C) environmental resistance D) density-dependent E) demographic
21) The trade-off between investments in current reproduction and in growth that promotes future reproduction is referred to as the total cost of what? A) adaptation B) selection C) reproduction D) genetic change E) fitness
22) A small group of mice are released on an island without mice but with abundant food for mice and no predators. Initially, the growth of the mouse population will be limited mainly by what?
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A) the carryingcapacity B) the bioticpotential C) onlydensity-dependent factors D) onlydensity-independent factors
23) A small group of mice were released on an island. The island previously had no mice on it, but had abundant food and no predators. After several years of growth, the size of the new island population stabilizes. However, at this point a hurricane drastically reduces the population. How would you describe the situation? A) The bioticpotential of the population has been reduced. B) The new population size is a result of density-dependent regulation. C) The new population size is a result of density-independent regulation. D) The island mouse population can now act as a sink metapopulation. E) The island mouse population can now act as a source metapopulation.
24) The biotic potential representing growth without limits at its maximal rate is indicated by what symbol? A) r i B) N C) K D) dN/dt E) N/K
25) In the sigmoid growth curve, the number of individuals at any one time is indicated by what symbol?
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A) r i B) N C) K D) dN/dt E) N/K
26) In the sigmoid growth curve, the carrying capacity of the environment is indicated by what symbol? A) r i B) N C) K D) dN/dt E) N/K
27)
The range of a population A) is very fluid and changes frequently in a random fashion. B) is stable and almost never changes. C) only changes after a disaster has wiped out a former range. D) changes over time due to external events. E) only changes due to iteroparity.
28)
Which is an example of a density-independent factor on a population? A) weather B) nesting sites C) intraspecificcompetition D) amount of prey E) predation
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29)
What do we call populations of organisms that are usually near the carrying capacity? A) K-selected B) r-selected C) predators D) parasites E) perennials
30)
Which of the following is an example of a species with r-selected adaptations? A) house fly B) blue whale C) gorilla D) horse E) cockroaches
31)
Which is an example of a species with K-selected adaptations? A) dandelion B) fruit fly C) herring D) bobcat
32) A species colonizes an island, goes through a phase of exponential growth, and reaches the carrying capacity of the island. At what stage is the growth rate slowest? A) initialcolonization B) exponentialphase C) approaching K D) after reaching K
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33) In the logistic growth model, as the number of individuals in the population (N) approaches the carrying capacity (K), what happens to the intrinsic rate of growth (ri)? A) It will beaffected by an increased birth rate. B) It will beaffected by a decreased death rate from predation. C) It will beaffected by increased competition with other species. D) It will beaffected by increased competition within the species. E) It will notchange.
34) During the late 1800s, cattle egrets arrived in South America from Africa and began to colonize. Their range has expanded dramatically over the years. Why were they able to do this? A) The habitats that they left in Africa were not suitable for any further colonization; thus, they were forced to emigrate. B) The habitats thatthey encountered in South America were suitable to them and unoccupied. C) There wereabundant cattle for the birds to gather around in South America; furthermore,various animals that the egrets had lived around in Africa had become quitescarce because of over hunting and poaching, causing the birds to extend theirrange. D) The food resourcesin South America were far superior to those in Africa, allowing the egrets moreopportunity to grow and reproduce and ultimately expand their range.
35)
Which is an example of a clumped distribution of a population?
A) A tree species releases a poison to defend the soil around its roots, resulting in trees spaced evenly like a grid. B) Antelope travel in herds. C) Two male hummingbirds have a confrontation on the border between their territories. D) Multiple species join each other at the waterhole to drink.
36) Many times species are composed of networks of distinct populations called metapopulations. When do metapopulations occur?
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A) Whena population is large and uniformly distributed. B) Whena population in poor habitat continually sends out dispersers to bolsterpopulations in better habitats. C) When a population in a better habitat does not send out colonizers into less suitable habitats. D) When suitablehabitat is patchily distributed and separated by areas of unsuitablehabitat.
37)
Which factor increases the likelihood of population extinction? A) large population size B) isolation of apopulation from density-independent effects C) isolation of a population from sources of immigrants D) high resourceavailability E) high geneticdiversity
38)
What is the Allee effect? A) when fitness increases independently of population size B) when fitness and growth rates increase with decreasing population size C) when fitness and growth rates increase with increasing population size D) when growth rates increase independently of population size
39)
What are population pyramids used to show? A) death rates B) birth rates C) competition D) age compositionof a population E) the carryingcapacity
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40) What kind of population spacing would you expect for a species that is strongly territorial? A) uniform B) clumped C) random D) uniform or clumpeddepending on whether it is a source or sink metapopulation E) uniform or clumpeddepending on the life history strategy of the species
41) You construct a life table for a plant species and find that in all cases about the same proportion of the cohort survive to the beginning of the next time interval. What would you call this? A) a Type Isurvivorship curve B) a Type IIsurvivorship curve C) a Type IIIsurvivorship curve D) a semelparous lifehistory adaptation E) populationsregulated by density-independent events
42) Allen's rule states that mammals from colder climates have shorter ears and appendages than individuals of the same species from warmer areas. The related Bergman's rule states that mammal body size varies with latitude, with larger body size in populations located closer to the poles and smaller body size in populations located closer to the equator. What can explain both of these rules? A) Larger bodies canstore proportionally more fat as insulation than smaller bodies. B) Smaller bodies canstore proportionally more fat as insulation than larger bodies. C) Heat loss increases as the surface area to volume ratio of the animal increases. D) Larger bodies havea proportionally larger surface area, and heat radiation varies withvolume. E) Smaller bodieshave a proportionally smaller surface area, and heat radiation increases withsurface area.
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43) Parental care of the young is usually associated with species with a type ___ survivorship curve. A) I B) II C) III D) I or II (depending on the sex ratio) E) I or III (depending on whether the reproductive strategy is iteroparous or semelparous)
44) Which one of the following expressions from the logistic equation (dN/dt = rN ((K N)/K) represents the proportion of unused resources remaining for use by the population? A) the carrying capacity (K) B) the population size ( N) C) the biotic potential (rN) D) (K - N)/K E) the growth rate ( dN/dt)
45)
Under which condition will a population experience growth? A) when N equals K B) when N is less than K C) when dN/dt equals zero D) when r equals zero E) when N equals zero
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46) What is the most reasonable conclusion that can be made from data graphed in the figure?
A) After high mortality early in life, survivorship becomes constant for the rest of life. B) Survivorship isconstant throughout life. C) After lowmortality early in life, mortality increases to a constant rate for the rest oflife. D) After following aconstant rate early in life, mortality becomes low late in life.
47) Most density-dependent factors show negative feedback relative to population size. Which one of the following is more likely to show positive feedback relative to population size? A) competition insmall populations B) competition inlarge populations C) fecundity insmall populations D) fecundity inlarge populations E) mortality inlarge populations
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48) The figure included shows the body temperature of lizards versus air temperature in two different habitats—open and shaded forest. Which one of the following conclusions is best supported by these data.
A) Lizards are more active in open habitats. B) Lizards sunbathemore in open habitats. C) Lizards in shaded forest habitats eat more to maintain their temperature. D) The body temperature of lizards is more constant in open than in shaded forest habitats. E) The negative effect of air temperature on body temperature is less in shaded forest habitats because the temperature varies less there.
49) Select the description of a population pyramid for a population that has the largest potential for exponential growth.
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A) broad at the base, narrow at the top, with more females than males B) broad at the base, narrow at the top, with more males than females C) uniform at all age classes, with more females than males D) broad at the top, narrow at the base, with more males than females E) broad at the top, narrow at the base, with more females than males
50)
What environmental challenge is posed to young plants by an old growth forest? A) low humidity B) hightemperatures C) low light D) thick leaflitter
51) You and your friends have just stepped off the plane in Cusco, Peru (11,200 ft). Your friends are so eager to see Machu Picchu they want to start off hiking the Inca Trail right away and not waste any time. How do you respond? A) "Sounds good,but we had better pack extra water." B) "Sounds good,but we had better bring our warmest clothes." C) "No problem --we had the whole plane ride to acclimatize to the high altitude." D) “Waiting a fewdays might be smart, since it takes time to acclimate to high altitude.”
52) A zoo in Southern California has been successfully breeding arctic wolves and they want to exchange some of their extra wolves for kangaroos from a zoo in southwestern Australia. Since it is July, it is quite cold in the other zoo compared to Southern California. What discussion might the zookeepers have about transferring the wolves?
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A) Since Arctic wolvesare well-adapted to cold, this should pose no problems. B) After severalgenerations in Southern California, the wolves have lost their adaptive genesfor cold temperatures. C) After growingup in Southern California, the individual wolves have lost their abilityto adapt to cold temperatures, but their progeny will still get thecold-adapted genes. D) Although the wolves are genetically adapted to cold weather have not grown their cold weather coats.
53) There are not many species of fish living deep in the oceans, but the deep-sea fish occasionally pulled up by fisherman have been bizarre creatures, such as the deep-sea anglerfish with its giant fangs and bioluminescent lure. Why have these fascinating deep-sea fish never been shown live on exhibit in an aquarium? A) Their diet is toospecialized. B) They are adaptedto cold temperatures and total darkness. C) They might frightenvisitors. D) They are adaptedfor high pressure, and will die at low pressure.
54) You and your friend are on vacation at Yellowstone Park. The plaque in front of a sulfur hot spring reads: “This sulfur spring is 80°C, has a pH of 2, and contains large amounts of sulfur which is oxidized by Sulfolobus species of archaea.” Your friend is excited. “Boy, if those microbes are that tough they should be easy to grow in the lab. I think I’ll work with those for my summer project.” What do you think? A) You agree, anddecide to partner with your friend to work on this organism as well. B) A species adaptedto such extreme conditions would probably not be easy to culture in the verydifferent conditions of a lab. C) The sulfur springis pretty extreme, but after a few days the individual archaea should haveadapted to lab culture conditions. D) The sulfur springis pretty extreme, but after a few generations the species should have adaptedto the lab culture conditions.
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55) You are earning your Ph.D. in marine biology, studying the microbial ocean community. This year, you are shocked to discover that one of your study sites has become contaminated due to an industrial waste water pipe. This dumping is drastically raising the temperature and lowering the salinity of the water. What do you expect to find in your survey of the ecosystem, and what might you find in a survey years from now? A) Most species willbe wiped out this year, and in subsequent years even fewer will remain. B) The individualswill turn on genes to adapt to these changes, and the populations will end uplargely the same this year and following years. C) Many species will have decreased or disappeared from this site, but later some species may increase in population if they acquire adaptive mutations. Also you may see some new species expand into the site. D) Most species willbe wiped out this year, and it will take millions of years for new species toevolve -- until then the site will be devoid of life.
56)
Which factor allows bacteria species to adapt to environmental changes faster than fish? A) shorter generation time B) smaller size C) smaller nutrientneeds D) lack of a nuclearmembrane
57) Kettle ponds derive from a hole left by a retreating glacier that is subsequently filled with rainwater. A certain region has a series of disconnected kettle ponds, but occasionally heavy rains flood them and create streams. Which type of animal is most likely to be present in this area as a metapopulation? A) a fish B) an aquatic bird C) a mosquito D) a dragonfly
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58) A farmer’s land includes a wilderness area that is home to an endangered species of bird. He wants to sell the land to a developer, and you have been hired to evaluate the environmental concerns. “This little patch of land is not crucial for the bird species!” the farmer says, “In fact, my land is surrounded by several other wilderness patches that also have that bird.” You reply: “It is possible that your land acts as the ____________ and the other areas are ___________ . If that's the case, development would be devastating to the population." A) sink; sources B) source; sinks C) population;metapopulation D) metapopulation;population
59) Within a genus that normally produces large numbers of offspring, one particular species evolves maternal care behavior. What do you predict will happen to the survivorship curve? A) No change islikely. B) It may change fromtype I to type III. C) It may change fromtype III to type I. D) It may change fromtype I to type II.
60)
Which organism is most likely to have a type III survivorship curve? A) an oak tree B) a domestic dog C) corn in a farmer'sfield D) Paramecium
61) An unscrupulous dog breeder has been selecting for dogs that have very large litters, with the goal of maximizing profits. Why might this strategy be counterproductive?
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A) It will cost toomuch money to feed all those puppies. B) Litter size is notinfluenced by genetics. C) The puppies fromlarge litters are likely to be malnourished, and the mother will have fewresources to devote to future litters. D) Intrauterinecannibalism will reduce the number of puppies.
62) A graduate student is studying the feeding behavior of a small octopus that must be laboriously collected from the shores of a remote island. Her intern wishes to do experiments to look at the octopus’s mating behavior. Why might the graduate student veto this idea? A) The octopus hassemelparous reproduction, and will eat its mate. B) The octopus hasiteroparous reproduction, and will eat its mate. C) The octopus hassemelparous reproduction, and will die after laying one batch of eggs. D) The octopus hasiteroparous reproduction, and will die after laying one batch of eggs.
63) A rancher is suspected of shooting wolves near Yellowstone National Park, and you have been enlisted to go have a chat with him. The rancher doesn’t see any benefit to having the wolves there. What do you say? A) "If there areno predators like wolves, just one pair of jackrabbits can quickly create apopulation with explosive, logistic growth. Wolves help reduce thefecundity rate, keeping the population at a reasonable level." B) "If there areno predators like wolves, just one pair of jackrabbits can quickly create apopulation with explosive, exponential growth. Wolves help reduce the carryingcapacity, keeping the population at a reasonable level." C) "If there areno predators like wolves, just one pair of jackrabbits can quickly create ametapopulation. Wolves help reduce the biotic potential, keeping the populationat a reasonable level." D) "If there areno predators like wolves, just one pair of jackrabbits can quickly create apopulation with explosive, density-dependent growth. Wolves help reduce the agestructure, keeping the population at a reasonable level."
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64) You are working in an aquarium that has been breeding an endangered species of fish for return into the wild. You have a batch of progeny from the first generation of breeding. The staff are discussing whether to return those fish to an area that has been completely depleted, or add them to a partially depleted population. “Considering the Allee effect, what do you say? A) “They may survive better in a large school, and will have an easier timefinding mates.” B) "They may dobetter in the empty area without any competition for food." C) "They may dobetter in the empty area without any competition for territory." D) "The area with the other fish may reduce the partially depleted population's exposure to disease."
65) This summer, you are returning to the research station in Costa Rica to follow up on the population of butterflies you have been studying. You are disappointed to find that there are fewer this year than last. In fact, at dinner your friends studying frogs and birds are complaining about the same thing. What type of influence do you suspect? A) adensity-independent effect like an introduced predator B) adensity-dependent effect like environmental disruption C) adensity-independent effect like environmental disruption D) adensity-dependent effect like an introduced predator
66)
What would be the best approach to curbing excessive human population growth? A) lowering birthrates through education and family planning B) a return to historical health care practices C) encouraging women to postpone children till after age 35 D) embracing traditional agricultural practices
67) A group of international students is having a heated discussion in the dining hall. “Your country needs to get its population under control!” asserts a student from the United States. “Perhaps,” replies the Indian student, “but your country ______________________.”
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A) has the highest per capita resource consumption, ten times greater than mine B) also has a big population overgrowth problem C) has a much higher birth rate D) has the lowest infant mortality rate
68) An important sporting event took place in Denver, Colorado (elevation: 5280 ft). Both teams were visiting the city for the event. Team A arrived a week in advance, but Team B arrived just one day before the game. What may have been a factor that contributed to Team B's poor performance? A) Team B acclimated to the high altitude, whereas Team A maintained physiological adjustment to their home town. B) Team B was from a country that did not give them experience with low altitude. C) Team B did not have enough time for their DNA to evolve in response to the high altitude. D) Team B did not have enough time for their bodies to adjust physiologically to high altitude.
69) A developmental biologist has decided to select a crustacean species to use as a new model organism. This will allow her to ask fundamental questions about the embryology of this important group of animals. What would be the best approach to find a good species to use for experiments? A) Collect pestspecies contaminating the wastewater system of the local marine aquarium. B) Collect the mostunusual species of crustacean from an exotic locale. C) Collect thelargest species of terrestrial crab. D) Collect a uniquespecies that lives on a specialized diet. E) Collect a variety of interestingcrustacean species – why stick with just one?
70) Would you expect that mated female fruit flies would live longer or shorter than unmated fruit flies, and why?
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A) Mated flies livelonger, because they use less energy traveling about looking for a mate. B) Mated flies liveshorter, because they use more energy in the act of mating. C) Mated flies liveshorter, because they use more energy producing eggs. D) Mated flies livethe same amount of time, because none of these factors is very significant.
71) What would happen to the COVID-19 case counts if the increases?
value of the SARS-CoV-2
A) They would increase. B) They would decrease. C) They would be kept constant. D) They would not be affected.
72)
What evidence is there for the adaptive evolution of the myxoma virus? A) It became less lethal. B) It had an increased . C) It nearly eliminated its host population. D) There is no evidence of adaptive evolution for the myxoma virus.
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SECTION BREAK. Answer all the part questions.
73)
73.1)
Which of the following statements about the graph is true?
A) Oysters live longer than Hydra. B) Hydra and humans have parallel life spans. C) Humans and oysters have similar life spans. D) Humans have lowmortality rates early in life. E) Oysters have highmortality rates late in life.
73.2)
What often describes organisms with a Type III life history?
A) K-selected B) r-selected C) idiopathic D) at their carryingcapacity E) subject to lowpredation rates
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73.3)
Which species would be most likely to have a Type III life history?
A) whale B) coconut palm C) lion D) gorilla E) pine tree
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Answer Key Test name: Chap 54_13e_Raven 1) TRUE 2) [A, B, D, F] 3) [A, D, E, G, J] 4) [B, D, E] 5) [D, E, F, G] 6) [A, C, D, E] 7) [B, C, D]
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Clarify question: What is the key concept addressed by the question? The key concept is to identify the types of animals that would be able to populate a newly formed island faster. What type of thinking is required? This is an application question. You will need to apply your knowledge of population dynamics to this situation. This is a check all that apply type of question, there is more than once correct answer. Gather Content: What do you already know about colonizing a new environment? What other information is related to the question? This is a newly formed island that rose out of the ocean. It clearly was never connected to the mainland. Of all the choices presented some will have a distinct advantage in terms of colonization speed. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Eventually all of the types of organisms listed may colonize the island but the ones with the ability to fly will probably be first. These species will have the easiest time crossing the open water. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? Were you to select all the correct answers? Animals that are able to fly would give them an advantage in populating a new and remote island. These situations actually happen, in 1883 the volcano Krakatoa blew itself up. The entire island was blasted in the air. In the 1920 a new island broke the surface and started to grow. The island is called Anak Krakatoa (son of Krakatoa) and has mature forests on it. 8) [A, B, C, E]
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Clarify question: What is the key concept addressed by the question? You are being asked to determine which factors would check the growth of a squirrel population. What type of thinking is required? This is an analysis question, you will need to break the question down into its components in order to get to the answer. This is a check all the apply question, there is more than one correct answer. Gather Content: What do you already know about factors that could slow down the growth of a squirrel population? What other information is related to the question? Populations can grow exponentially when they are getting optimal amounts of resources and have very few forces acting to reduce the population size. In nature these conditions can persist for a short time but many factors can prevent this kind of growth from lasting. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Habitat loss, increased predation, loss of a major food source, and famine can all act to slow down population growth and reduce the population size. Reflection on Process:
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to select all the correct answers? The key was to break down the choices and determine which ones would negatively affect the population growth rate. 9) [A, C, E]
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Clarify question: What is the key concept addressed by the question? You are being asked to determine some factors that could increase the carrying capacity for a human population in a developing country. What type of thinking is required? This is an analysis question, you will need to break the question down into its components in order to get to the answer. This is a check all the apply question, there is more than one correct answer. Gather Content: What do you already know about the carrying capacity of a population? What other information is related to the question? Carrying capacity is the size of the population that can be supported by the environment. All individuals in the population consume some amount of resources. Anything that increases the amount of resources available or reduces the amount of resources an individual would use will increase the carrying capacity. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? The carrying capacity is the maximum number of individuals that a given environment can support. Anything that increases the food or water resources available to support people would increase carrying capacity, such as improved crop yields, a shift to vegetarian diets (which require far less land per calorie of food produced), and water treatment plants to produce clean water. Version 1
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Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to select all the correct answers? You needed to break down each of the choices and see if they could possibly increase the carrying capacity of the environment.Increasing the carrying capacity involves being able to support more individuals in the population, not limiting the size of the population. 10) [C, D] 11) A 12) C 13) D 14) A 15) A 16) B 17) C 18) B 19) B 20) D 21) C 22) B 23) C
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Clarify question: What is the key concept addressed by the question? The key concept is the impact of a natural event on a population of mice. What type of thinking is required? This is an analyze question, you will need to break the question down into its components to determine the answer. You will need to determine how a hurricane effects a population of mice on an island. Gather Content: What do you already know about natural event affecting a population? What other information is related to the question? Metapopulations are a group of small semi-isolated populations spread across an area. Density-dependent effects are changed by the population size whereas density-independent processes are not effect by the population size. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? The hurricane is independent of the size of the mouse population; it is an example of a density-independent process. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? You need to break down the question into all its components to determine the correct answer. Were you able to analyze each situation Version 1
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and determine what type of impact the hurricane had on the mouse population, knowing that the population size had no influence on the results of this natural disaster? 24) A 25) B 26) C 27) D 28) A 29) A When resources are limited, the cost of reproduction often will be very high. Consequently, selection will favor individuals that can compete effectively and utilize resources efficiently. Such adaptations often come at the cost of lowered reproductive rates. Such populations are termed K-selected because they are adapted to thrive when the population is near its carrying capacity ( K). Examples of K-selected species include coconut palms, whooping cranes, whales, and humans. By contrast, in populations far below the carrying capacity, resources may be abundant. Costs of reproduction are low, and selection favors those individuals that can produce the maximum number of offspring. Selection here favors individuals with the highest reproductive rates; such populations are termed r-selected. Examples of organisms displaying r-selected life history adaptations include dandelions, aphids, mice, and cockroaches. Most natural populations show life history adaptations that exist along a continuum ranging from completely r-selected traits to completely Kselected traits. 30) A 31) D 32) D 33) E 34) B Version 1
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Clarify question: What is the key concept addressed by the question? You will need figure out how egrets that were adapted to life in Africa were able to successfully colonize South America. What type of thinking is required? This is an analyze question, you will need to break the question down into its components to determine the answer. Gather Content: What do you already know about what impacts the colonization of a new habitat? What other information is related to the question? If a species is going to successfully colonize a new area it must be able to survive and reproduce in the new area. If a species is adapted to survive in its ancestral area, what must be true about the new area that is being colonized? Choose Answer: Given what you now know, what information is most likely to produce the correct answer? The range of a population may expand either because environmental changes improve the suitability of a new region, or because a chance event allows a species to cross a barrier into a new suitable region. The relative quality of the old range has no bearing on whether the population will expand into the new region. In the example of the cattle egret, some chance crossing of the Atlantic allowed the species to arrive in South America in the 1880s, and the population has gradually expanded both northward and southward into all suitable regions. Version 1
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Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to analyze each scenario in terms of how it impacts the ability of the egret population to expand its range and what factors would be important and what factors wouldn't provide any advantages? 35) B Social interactions between members of a species can lead to clumped distributions. Many species live and move around in large groups (such as flocks, herds, or prides). These groupings can provide many advantages, including defense against predators, decreased energy cost of moving through air and water, and access to the knowledge of all group members. 36) D 37) C 38) C 39) D 40) A 41) B 42) C 43) A 44) D 45) B 46) C 47) C 48) D
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49) A 50) C
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Clarify question: What is the key concept addressed by the question? The key concept is about identifying challenges a young plant would face in a mature developed forest. What type of thinking is required? This is an analyze question, you will need to break the question down into its components to determine the answer. Gather Content: What do you already know about the conditions that exist in a mature forest environment? What other information is related to the question? A young plant needs light, nutrients, and water in order to grow. In an old-growth forest with mature trees there will be plenty of water and nutrients. The abundance of tall trees presents a problem for the plant. The mature trees are full of leaves and absorb almost all of the available sunlight. Without enough light the young plants will not be able to do photosynthesis. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Light is the biggest problem for the young plant. The forest canopy absorbs 95%+ of the light that is why it is so dark in a mature forest. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? Were you able to make the correct choice? You needed to break down the question and figure out which components of the mature forest habitat would provide the biggest challenge for a young plant. 51) D 52) D
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Clarify question: What is the key concept addressed by the question? The key concept is identifying how the cold weather would impact the wolves. What type of thinking is required? This is an application level question, you will need to apply what you know about adaptation to cold climates to the situation with the wolves. Gather Content: What do you already know about the cold weather adaptations in wolves? What other information is related to the question? These wolves are living in a zoo and are being transferred to another zoo where it is very cold. Temperatures in the wolves’ natural habitat range from warm to very cold but the change is gradual. The wolves have time to adapt to the changes in the climate. How is this situation different from the natural climatic cycle? Choose Answer: Given what you now know, what information is most likely to produce the correct answer? The wolves need to grow their winter coats, normally that takes place as the weather cools at the end of the summer. They wouldn’t have time to grow them on the short flight over to Australia. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result Were you able to identify the challenges the wolves, who were raised in a warm weather environment, would encounter in a cold weather environment? 53) D
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Clarify question: What is the key concept addressed by the question? The key concept is to identify the conditions in the deep sea that would prevent establishing a similar environment in an aquarium. What type of thinking is required? This is an analyze level question, you will need analyze each scenario to see which would most accurately answer the question. Gather Content: What do you already know about the deep sea environment? What other information is related to the question? Deep sea environments are cold and dark. The darkness and cold temperatures are easy to replicate in an aquarium setting. What is the other major environmental factor the makes the deep sea different from the upper reaches? Choose Answer: Given what you now know, what information is most likely to produce the correct answer? The most difficult requirement of deep-sea fish is high pressure. They are adapted to the extreme pressure of the deep sea, and without that pressure their cells and tissues will not function properly and they will die. Bringing a deep-sea fish up to the surface and constantly maintaining the appropriate pressure is a major challenge to ever displaying these animals at the surface. Reflection on Process: Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to make the correct choice? You needed to break down the question and consider each of the major components of a deep sea environment and if they could be replicated in an aquarium. 54) B
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Clarify question: What is the key concept addressed by the question? The key concept is the environmental conditions in which the archaea species exists and if that can be replicated in the lab. What type of thinking is required? This is an evaluate level question, you will need to consider each of the choices and make a judgement as to which is the best response to the statement made in the question. Gather Content: What do you already know about replicating the environmental conditions of hot springs in the lab? What other information is related to the question? Water that is 80 degrees Celsius and had a pH of 2 is essentially boiling acid. This environment would instantly kill almost any living organism. In order to survive in such an environment, any organism would have to have very specialized adaptations. These conditions are very different from typical laboratory conditions. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? It would probably be very hard to grow these species under typical lab conditions. All adaptations have costs and the costs of these adaptations would be very high. Reflection on Process: Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? You need to consider all of the choices and judge between all of them. Were you able to correctly identify that the extreme environmental conditions of the hot springs cannot be replicated in the lab, but without those conditions the microorganisms cannot survive? 55) C
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Clarify question: What is the key concept addressed by the question? The key concepts is predicting how an environment will be affected by pollution. What type of thinking is required? This is an analyze level question, you will need to break down the question into its components to get to the answer. Gather Content: What do you already know about how an ecosystem reacts to pollution? What other information is related to the question? The environment has experienced a drastic change. Initially most species will not be adapted to this different environment, but if the change is persistent over a long span of time what will happen? There will be a new set of selection pressures on the community. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? After an initial decrease in the population, some species will adapt. Also some species may be better suited to live in the new set of conditions. Some species may have been held to low levels because of ecological interaction with other species, but with those competing species gone their population may begin to expand. Also there may be new species that can now live in the newly modified environment. Reflection on Process: Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to make the correct choice? Changes to an environment are often initially detrimental but given the short generations of microbial species, they can quickly respond to new sets of selection pressures. 56) A
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Clarify question: What is the key concept addressed by the question? The key concept is to identify the characteristic that of bacteria that makes them better able to adjust to changing environmental conditions. What type of thinking is required? This is an application question, you will need to apply what you know about selection to the situation being presented. Gather Content: What do you already know about the characteristics of bacteria that might allow them to respond to changes in their environment? What other information is related to the question? Selection acts to favor the best adapted individuals, these individuals reproduce and pass their genes to the next generation. Bacteria can reproduce every 20 minutes given enough resources. Fish cannot reproduce nearly as fast. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? The shorter generation time in bacteria is going to allow them faster adaptation to a changing environment. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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Were you able to identify the shorter generation time as being the factor that will give bacteria the advantage in adapting to a changing environment? 57) A
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Clarify question: What is the key concept addressed by the question? The key concept is to identify the type of organism that will form a metapopulation under these conditions. What type of thinking is required? This is an analyze question, you will need to break down the question into its components to get to the answer. Gather Content: What do you already know about metapopulations? What other information is related to the question? A metapopulation is a series of small populations that on their own would not be large enough to form a stable single population. The series of populations are intermittently connected to each other and the whole group of sub-populations forms a metapopulation. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Birds, mosquitos, and dragonflies can all freely move across the area. They would not be considered a metapopulation because they are not confined to separate sub-populations. Small populations of fish in the kettle ponds would be a metapopulation. The populations would be separate for most of the year, only joining when floods connected the separate kettle ponds. Reflection on Process: Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to make the correct choice? You needed to break the question down and see which of the answer choices matched the definition of a metapopulation. 58) B
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Clarify question: What is the key concept addressed by the question? The key concept is to identify how the different wilderness patches relate to each other in affecting this endangered species of birds. What type of thinking is required? This is an evaluate question, you will need to make a judgment between all of the possible answers choices. There are two terms that you must select to make the statement correct. Gather Content: What do you already know about metapopulations? What other information is related to the question? A metapopulation is a series of small populations that on their own would not be large enough to form a stable single population. The series of populations are intermittently connected to each other and the whole group of sub-populations forms a metapopulation. In a metapopulation the sources are the larger more stable populations and the sinks are the small populations that are not sustainable. The sink areas are constantly being replenished by the source areas. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? If the farmer’s land were the source area for the metapopulation and the other areas were the sinks then if the farmer sold his land to the developer the source population would be destroyed. If that happened it would only be a matter of time before the smaller sink populations Version 1
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became depleted. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to make the correct choice? You needed to weigh each of the choices and decide which one made the statement about the farmer’s land correct. Metapopulations are dynamic and changing populations but without the source sub-populations the meta population cannot persist. 59) C 60) A
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Clarify question: What is the key concept addressed by the question? Identify an organism that exhibits the characteristics of a type III survivorship curve. What type of thinking is required? This is an analysis question, you will need to break the question down into its components in order to get to the answer. You will need to figure out which species has a type III survivorship curve. Gather Content: What do you already know about the characteristics of a type III survivorship curve? What other information is related to the question? Paramecia reproduce by mitosis, which only produces two new paramecia. The dog and the corn produce a smaller number of offspring. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? One single oak tree produces thousands of acorns, sometimes up to 10,000 acorns if it is particularly good year. There is a huge attrition rate, only a tiny fraction of the acorns successfully germinate and only a tiny fraction of the young trees survive to be large mature oaks. The oaks obviously follow at type II curve with very high juvenile mortality. Reflection on Process: Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to select the correct answer? You needed to to break down each choice and figure out what would be the reproductive strategy for each species thereby being able to identify the one that exhibits a type III curve. 61) C
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Clarify question: What is the key concept addressed by the question? In this question you will need to figure out why produce a large litter of puppies maybe counterproductive to the goal of having lots of puppies to sell. What type of thinking is required? This is an analysis question, you will need to break the question down into its components in order to get to the answer. Gather Content: What do you already know about the risks versus benefits of producing a large little of puppies? What other information is related to the question? What would happen if the dog breeder only wanted huge litters? Dogs are iteroparous, meaning that they can breed multiple times during their lifetime. If they produce one huge litter of puppies, those puppies may be of low quality and it might compromise the mother's future breeding potential. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Instead of producing one large litter of low quality puppies, the strategy of procuring fewer higher quality litters over a longer period of time would probably produce the highest number of good quality puppies. Reflection on Process: Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you to select all the correct answers? The key here was to break down the question and see the trade-off between quality and quantity of offspring. 62) C 63) B
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Clarify question: What is the key concept addressed by the question? In this question you are being asked to explain the benefits of having wolves. What type of thinking is required? This is an analysis question, you will need to break the question down into its components in order to get to the answer. Gather Content: What do you already know about the benefits of wolves in a community? What other information is related to the question? When breaking down the answer choices the difference between all the choices is exactly what effect the wolves are having on the rabbits. Do the wolves reduce the fecundity rate, carrying capacity, biotic potential, or the age structure? Wolves eat rabbits, but this does not reduce the number of offspring a rabbit could potentially have. Wolves are most likely going to eat younger rabbits who are less experienced at avoiding wolves, thus they will not reduce the age structure of the population. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? The answer is that wolves reduce the carrying capacity of the rabbit. Without wolves acting as a predator the population size of the rabbit would be higher. The wolves act as a break on the growth of rabbits. There are many other factors that play a role in determining the carrying capacity for the rabbits. The wolves are just one of many factors that can Version 1
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act to reduce it. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you able to select the correct answer? The key was to break down the choices and see what effect was the best choice. In the case, the wolves serve to control the population size of another animal that could be more detrimental to the rancher. 64) A
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Clarify question: What is the key concept addressed by the question? You are being asked to consider how the Allee effect would modify your thinking when it comes to introducing an endangered fish into the wild. What type of thinking is required? This is an analysis question, you will need to break the question down into its components in order to get to the answer. . Gather Content: What do you already know about the Allee effect? What other information is related to the question? The Allee effect is a correlation between individual fitness and the population size. As the population size increases the individual fitness of each individual also increases. Living in a larger group provides more opportunities for finding mates and decreases and individual’s risk of predation. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Considering the Allee effect, introducing the fish into an existing school would give them the best chance of surviving. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? Were you able to select the correct answer? You needed to break down the answer choices and determine which one would give the young fish the best chance of surviving. 65) C
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Clarify question: What is the key concept addressed by the question? You are being asked to explain the cause of a large drop in populations of several unrelated species. What type of thinking is required? This is an analysis question, you will need to break the question down into its components in order to get to the answer. Gather Content: What do you already know about factors that affect many different populations of organisms? What other information is related to the question? Density-dependent effects change as the population size changes. Diseases are a good example, a disease will have an easier time spreading in a large population especially if the individuals live close together. Density-independent effects are not affected by population size. Hurricanes and other natural disasters are good example of densityindependent effects. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? A density-dependent environmental disruption is the most likely explanation for a drop in the population size of several unrelated species in one particular area. Reflection on Process: Version 1
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Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Were you to select all the correct answers? You needed to break down the answer choices to figure out which one would best explain the drop in populations. Also you needed to figure out that an environmental disturbance was a density-independent effect. 66) A 67) A 68) D
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Clarify question: What is the key concept addressed by the question? This question addresses how elevation affects athletic performance. What type of thinking is required? This is an analyze level question, you will need to look at all the choices and break them down into their components in order to figure out why team B is struggling when compared to team A. Gather Content: What do you already know about the effects of elevation on physiology? What other information is related to the question? This question comes from the section of the text that deals with environmental changes and the physiological adjustments that are needed to cope with the changes. High altitudes have less oxygen than lower altitudes; physiological adjustment called acclimatization can occur. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Acclimatization is possible but it takes time. Typically symptoms of altitude sickness disappear after a day or so. It isn’t a genetic difference between both teams; both teams are capable of adjusting physiologically to the lower oxygen levels. It is a question of time. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Answering this question correctly depended on being able to break Version 1
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down the answer choices and realize that it is a physiological adjustment instead of a genetic change that occurs. Were you able to arrive at the correct answer? 69) A
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Clarify question: What is the key concept addressed by the question? Deciding what species of crustacean would best serve as a model organism to study the characteristics of all crustaceans. What type of thinking is required? This is an evaluate level question. You are being asked to make a judgement concerning the ideal species to use as a model organism. All of the choices are features of potential species, but you need to select the best one. Gather Content: What do you already know about crustaceans' abilities to respond to their environment and what characteristics are best in a model organism? What other information is related to the question? This relates to an organism's ability to adapt to changes in the environment. A model organism will be grown and maintained in a lab setting and subjected to many different experimental situations to determine how an entire group of organisms responds to changes. It must be relatively robust and have the ability to grow and thrive in a variety of environmental conditions. All of the organisms must be the same in order to eliminate variability in the experiment. Being very large or have a very specific diet makes it more difficult to grow and maintain large colonies of organisms. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Pest species can often survive in degraded environments that are not suitable for many other species. The adaptability to a wide range of Version 1
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environmental conditions makes them ideal choices to living and growing in laboratory and experimental conditions. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Answering this question correctly depended on being able to consider all of the choices and figure out which species would be the most beneficial as a model organism. Were you able to make the correct evaluation? 70) C
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Clarify question: What is the key concept addressed by the question? The key concept is the factors that affect lifespan of a female fruitfly. What type of thinking is required? This is an analysis question; you will need to break down the question and answers into their components to determine the correct answer. In this question you will need to decide if mated flies have longer or shorter lifespans than unmated flies. You will also need to select the correct explanation for the difference in lifespan. Gather Content: What do you already know about factors affecting lifespans? What other information is related to the question? Finding mates and the act of mating aren’t particularly expensive in terms of energy. Once the female fly has mated she needs to produce the eggs. Eggs are protein rich and provide the developing fly with lots of energy; consequently it costs a lot of energy to produce eggs. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? It makes sense the mated female flies would not live as long as unmated flies. The mated flies dedicate lots of energy to the production of eggs. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? The key to this question is to figure out that the main cost of reproduction for females is the production of eggs. Were you able to select the correct answer? 71) A 72) A 73) Section Break 73.1) D
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Clarify question: What is the key concept addressed by the question? The key concept is to analyze the graph and determine how the survivorship curves relate to each other. What type of thinking is required? This is an analyze question, you will need to analyze the graph to extract the data you need to answer the question. Gather Content: What do you already know about the characteristics of the three survivorship curves? What other information is related to the question? How does the type III survivorship curve differ from the type I or the type II curves? Where does the maximal rate of mortality occur? Choose Answer: Given what you now know, what information is most likely to produce the correct answer? In a type III curve there is very high initial mortality followed by a sharp decrease in mortality rate once the organism survives to adulthood. The strategy of producing lots of offspring is the best strategy to use here, which is the r-selected strategy. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more Version 1
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desirable result? You needed to extract the information from the graph and decide which strategy was best. Were you able to determine from the graphs how each survivorship curve related to mortality rates and life spans for members of the population? 73.2) B 73.3) E
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Clarify question: What is the key concept addressed by the question? The key concept is to identify which organism exhibits the characteristics of a type III survivorship curve. What type of thinking is required? This is an analyze question, you will need to break down each of the answer choices and figure out which one most likely follows a type III survivorship curve. Gather Content: What do you already know about a type III survivorship curve? What other information is related to the question? Due to the extremely high mortality rates for juveniles, investing lots of energy in each offspring is not a good use of energy for organisms that follow a type III survivorship curve. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Whales, lions, and gorillas all invest a lot of energy into each of their offspring. A coconut palm produces a few very large seeds (coconuts) that are loaded with energy for the developing plant. Pine trees produce thousands of seeds at a time. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you Version 1
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astray? How can you revise your approach to produce a more desirable result? Were you able to make the correct choice? You needed to break down the type III survivorship curves and apply it to all of the choices to pick out which organism was the best example.
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Chapter 55 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) Interspecific competition can affect the phenotypic characteristics of organisms. ⊚ ⊚
true false
2) Geographical allopatry between species is definitive evidence of interspecific competition. ⊚ ⊚
true false
3) When there are high levels of disturbance in a community, the number of K-selected species should increase along with the overall diversity of the community. ⊚ ⊚
true false
4) In general, communities in early succession will be dominated by fast-growing species with r-selected life histories. ⊚ ⊚
true false
5) Resource partitioning would be most likely to occur between allopatric populations of species with similar ecological niches. ⊚ ⊚
6)
true false
Mimicry is a form of camouflage. ⊚ ⊚
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CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 7) Which of the following are types of symbioses? Check all that apply. A) Batesian mimicry B) commensalism C) predation D) parasitism E) mutualism F) Müllerian mimicry
8) Which of the following examples would be undergoing secondary succession? Check all that apply. A) an abandoned potato farm B) a coastal grassland damaged by a hurricane C) an abandoned landfill D) rocks in a national park covered by mosses and lichens E) a garden bed that has been weeded
9) In studies of two species of barnacles in the marine intertidal zone it was observed that Chthamalus can live in the upper intertidal zone and the lower intertidal zone if Semibalanus is absent, and Semibalanus can only live in the lower zone because it is more subject to dehydration. Based on this, which of the following statements are true? Check all that apply. A) The realized niches of the two species differ. B) The fundamental niche of Chthamalus is larger than its realized niche. C) The fundamental niche of Chthamalus is larger than the fundamental niche of Semibalanus. D) The fundamental and the realized niches of Chthamalus are the same. E) The fundamental and the realized niches of Semibalanus are the same.
10) Which of the following statements about the fundamental and realized niche are true? Check all that apply.
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A) A species' realized niche could be the same size as its fundamental niche. B) A species' realized niche could be smaller than its fundamental niche. C) A species' fundamental niche can be smaller than its realized niche. D) The extent of the realized niche is determined, in part, by interspecific competition. E) The extent of the fundamental niche is determined, in part, by conditions of the physical environment.
11) Which of the following factors could be important in determining a species' fundamental niche? Check all that apply. A) salinity B) presence of a commensalist C) presence of a predator/parasite D) seasonal temperatures
12) Which of the following would be an expected long-term change during primary succession on glacial moraines? Check all that apply. A) increase in species richness B) decrease in soil depth C) increase in soil salinity D) increase in soil nitrogen E) alder replaced by spruce
13) Which of the following statements about the intermediate disturbance hypothesis are true? Check all that apply.
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A) The intermediate disturbance hypothesis predicts that most communities eventually reach an end-state or climax community. B) Intermediate disturbance should lead to increases in species richness. C) Disturbances tend to lead to the dominance of K-selected species. D) An example of intermediate disturbance would be a tree fall in a mature rain forest. E) Intermediate disturbance should lead to all successional stages being present in the community at the same time.
14)
Which of the following statements about mimicry are true? Check all that apply.
A) Generally, the number of mimics in a Müllerian mimicry system must be less than the number of models B) Only Batesian mimicry depends on the ability of the predator to learn. C) In Müllerian mimicry, the participants are both mimics and models. D) In Batesian mimicry, the participants are either mimics or models. E) A Müllerian mimic is "a sheep in wolf's clothing."
15)
Which of the following statements about predation are true? Check all that apply. A) Cycling of predator and prey populations is not commonly observed. B) Removal of a predator often leads to increased community stability. C) Animal predation on plants is called herbivory. D) Predation can induce coevolutionary changes in prey species. E) Batesian mimicry is not a coevolutionary adaptation to predation.
16) Following their respective breeding seasons, several species of hummingbirds occur at the same locations in North America and several hummingbird flowers bloom simultaneously in these habitats. These flowers seem to have converged to a common morphology and color. Birds are most visually sensitive to the color red. Hummingbird flowers are pollinated by hummingbirds. Which of the following features of these flowers would indicate they have coevolved with hummingbirds? (Check all that apply)
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A) long tubular flowers B) flowers are colored violet and blue C) blooming time of the flowers coincides with the arrival of the hummingbirds D) flowers produce a high volume of nectar and sugar E) flowers are low to the ground
17) Forests, like other ecological systems, are subject to the species succession process. Which of the following would be characteristics of pioneer plant species facilitating the early stages of forest succession? (Check all that apply) A) slow-growing B) pollinated by animals C) seedling growth requires direct sunlight D) seeds germinate in the shade E) plants produce great quantity of seeds
18) Communities with a high level of bacterial diversity are found in many habitats including soil and aquatic environments. Recent studies indicate this diversity is crucial to the functioning of these communities. The same studies have also found that phage abundance plays a critical role in the maintenance of the bacterial diversity within these communities. What is the probable role of phages in this community? (Check all that apply) A) they act as facilitators B) they have a mutualistic relationship with the bacteria C) they parasitize the bacteria D) they have a commensal relationship with the bacteria E) they compete with the bacteria for space and nutrients F) they keep any one species of bacteria from becoming too abundant in the community
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 19) All organisms living together in a place are called a
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A) community. B) population. C) species. D) ecosystem.
20)
Competition shapes communities because there are usually limited A) species. B) resources. C) interactions. D) nutrients.
21)
Two organisms trying to utilize the same resource is called A) synergy. B) parasitism. C) competition. D) interference.
22) Two species of warblers colonize the same island habitat. Both species nest in similar locations and eat the same type of prey. Eventually, competition will probably cause one species to A) migrate. B) grow exponentially. C) speciate. D) be eliminated.
23) Aposematic, or warning coloration, serves to protect an animal or plant by signaling to potential ________ to stay away.
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A) competitors B) predators C) mates D) rivals
24)
In _______ mimicry, unprotected species resemble others that are distasteful. A) Müllerian B) competitive C) Batesian D) aposematic
25) In ________ mimicry, two or more unrelated but protected species resemble one another, thus achieving a kind of group defense. A) Batesian B) disruptive C) Müllerian D) cooperative
26) A _________ relationship is one in which two or more kinds of organisms live together in often elaborate and more or less permanent association. A) symbiotic B) parasitic C) mutualistic D) synergistic
27)
The way in which an organism utilizes its environment may be called
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A) resource partitioning. B) its habitat. C) competitive exclusion. D) intraspecific competition. E) its niche.
28)
A relationship in which both members benefit is called A) predation. B) parasitism. C) mutualism. D) commensalism. E) sympatric.
29)
Communities evolve to have greater biomass and species richness in a process called A) sympatric interactions. B) adaptive modifications. C) succession. D) symbiotic relationships. E) competitive exclusion.
30)
Paleontological studies indicate that, over millions of years,
A) groups of species that have coevolved rise and go extinct together. B) species that occurred together in the distant past still occur together today; the community has held constant. C) the extinction of species is not related to the community in which they lived. D) species seem to come and go individually as niches within a community become available. E) species richness is constant over time.
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31) its
The actual niche the organism is able to occupy in the presence of competitors is called
A) fundamental niche. B) realized niche. C) interference niche. D) intraspecific niche. E) exploitative niche.
32)
Competition between species is called ____________ competition. A) interspecific B) exploitative C) interference D) fundamental E) intraspecific
33) Resource partitioning can often be seen in similar species that occupy the same geographic area. These species avoid competition by living in different portions of the habitat or by utilizing different food or other resources and are called ____________ species. A) sympatric B) allopatric C) competitive D) fundamental E) exploitative
34) Chemicals that play the dominant role in protecting plants from being eaten by herbivores or predators are called
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A) primary compounds. B) secondary compounds. C) poisons. D) oils. E) amino acids.
35) Cardiac glycosides, molecules causing a drastic effect on vertebrate heart function, are produced as defensive chemicals by plants belonging to A) the milkweed and dogbane families. B) the mustard family. C) the grass family. D) the poison ivy, oak, and sumac families. E) the bean family.
36)
Chemical defenses are found in all of the following except A) marine animals. B) insects. C) plants. D) snakes, spiders, and fishes. E) Batesian mimics.
37)
Insects that lay eggs on living hosts are called A) ectoparasites. B) endoparasites. C) brood parasites. D) parasitoids. E) predators.
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38) Alligators excavate holes in the bottom of bodies of water. During times of severe drought these holes act as refugia for various aquatic organisms that might perish if there were no water available. Thus, alligators in this system can be classified as a(n) A) keystone species. B) symbiotic species. C) sympatric species. D) allopatric species. E) refugistic species.
39) Succession happens because species in the habitat alter that habitat in ways that assist other species. There are three dynamic concepts that are of critical importance for succession to take place. They are A) establishment, facilitation, and inhibition. B) symbiotic relationships, facilitation, and aposematic coloration. C) establishment, coevolution, and competitive exclusion. D) competition, climax communities, and tolerance. E) competition, inhibition, and coevolution.
40) A species that plays a critical role in maintaining the structure of an ecological community and helps to determine the types and numbers of various other species in the community is known as A) a predator. B) a keystone species. C) the primary species. D) the dominant species. E) the alpha species.
41)
Lakes become eutrophic by
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A) accumulation of organic matter. B) loss of organic matter. C) circulation of water in the lake. D) free exchange of water with outside sources. E) an increase in the number of organisms.
42)
The difference in the fundamental niche and the realized niche is
A) the fundamental niche is the actual niche that a species occupies while the realized niche is the potential area that the species is capable of inhabiting. B) the fundamental niche is the entire niche that a species is capable of using while the realized niche is just what is being occupied. C) the fundamental niche is smaller than the realized niche. D) the realized niche is theoretical while the fundamental niche is the entire niche that an organism can use.
43) During the mid 1930s, G. F. Gause studied competition among three species of Paramecium. Through his experiments he formulated a principle of A) niche overlap. B) exploitative competition. C) metapopulation fluctuation. D) competitive exclusion. E) interspecific competition.
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44) Two of Darwin's finches display a character displacement when they occur as sympatric species. Which of the statements correctly interprets the graph?
A) Both species have the same size beak on Santa Maria Island. B) Both species have the same size beaks on Daphne Major. C) Both species have the same size beaks on Los Hermanos Island. D) The two species have different beak sizes when they occur on the same island. E) The two species feed on different food resources; one feeds on seeds while the other feeds on insects.
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45)
Which statement is the correct interpretation of the graph?
A) The population of Didinium goes extinct with the addition of Paramecium on day 4. B) The population of Didinium continues to increase and remains high even after the extinction of the Paramecium. C) The population of Paramecium goes extinct with the addition of Didinium on day 8. D) The population of Didinium increased but then went extinct after the population of Paramecium went extinct. E) The population of Didinium is able to increase at the expense of the Paramecium population. After a brief period both populations are able to coexist.
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46) Based on the following graph, what is the most likely relationship between Paramecium and Didinium?
A) Paramecium prey on Didinium. B) Paramecium have a commensal relationship with Didinium. C) Didinium and Paramecium have a mutualistic relationship. D) Didinium prey on Paramecium. E) Paramecium is a parasite that feeds on Didinium.
47) Which of the following statements accurately reflects the differences between Batesian mimicry and Müllerian mimicry?
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A) In Batesian mimicry the model must behave differently than the mimic; in Müllerian mimicry they behave the same. B) In Batesian mimicry the model must be more dangerous than the mimic; in Müllerian mimicry they are both dangerous. C) Batesian mimicry does not differ from Müllerian mimicry. Two different scientists discovered these two types at the same time, and they disagreed on what to call it. D) Batesian mimicry differs from Müllerian mimicry in that they occur on different continents—Batesian on the North American and Müllerian on the European. E) Batesian mimicry involves invertebrates; Müllerian mimicry involves vertebrates.
48)
Which of the following is an example of commensalism? A) a tapeworm living in the intestines of a mule deer B) barnacles hitching a ride on the skin of a whale C) a female mosquito sucking blood from a musk oxen D) wood-digesting flagellates living in the gut of termites E) acacia trees and their ants
49) In India, golden jackals that have been expelled from their pack have been known to attach themselves to a particular tiger, trailing it at a safe distance in order to feed on the big cat's kills. What type of relationship exists between the jackal and the tiger? A) mutualism B) predation C) parasitism D) competition E) commensalism
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50) You have been studying the relationship between jackals and tigers in India. Until recently, the only relationship you have observed is that jackals will associate themselves with a particular tiger and follow it at a safe distance in order to feed on the big cat's kills. However, recently you observed a jackal alerting a tiger to a kill with a loud cry. If you continue to observe this alerting behavior, you might change the categorization of the jackal/tiger relationship from ___________ to __________________. A) mutualism; parasitism B) mutualism; commensalism C) commensalism; mutualism D) parasitism; mutualism E) competition; predation
51) Cattle egrets follow African ungulates such as African buffalo around and catch insects that the buffalo flush out. Oxpeckers perch on the backs of buffalo and feed on ectoparasites that infest the buffalo. Which one of the following shows the ecological interaction that the buffalo has with each bird? A) cattle egret: mutualism; oxpecker: commensalism B) cattle egret: commensalism; oxpecker: mutualism C) cattle egret: competition; oxpecker: mutualism D) cattle egret: mutualism; oxpecker: mutualism E) cattle egret: commensalism; oxpecker: commensalism
52) Garlic mustard is an invasive plant species in North American temperate forests. Garlic mustard secretes an allelochemical that damages the relationship between native tree roots and their mycorrhizal fungi. This would be an example of A) interference competition. B) exploitative competition. C) intraspecific competiton. D) commensalism.
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53) Following their respective breeding seasons, several species of hummingbirds occur at the same locations in North America and several hummingbird flowers bloom simultaneously in these habitats. These flowers seem to have converged to a common morphology and color. Birds have the most visual sensitivity to the color red. Following their breeding season, these species of hummingbirds are A) allopatric. B) sympatric.
54) Communities with a high level of bacterial diversity are found in many habitats including soil and aquatic environments. Recent studies indicate this diversity is crucial to the functioning of these communities. The same studies have also found that phage abundance plays a critical role in the maintenance of the bacterial diversity within these communities. Are phages a density-dependent or a density-independent regulating factor? A) density-dependent B) density-independent
55) In which habitat would you expect to encounter community assemblages that are most similar? A) Freshwater streams in North America and Europe. B) A savannah and a tropical rain forest. C) The pelagic and intertidal zones of the same ocean. D) A freshwater lake within a deciduous forest.
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Answer Key Test name: Chap 55_13e_Raven 1) TRUE
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Clarify question: What is the key concept addressed by the question? The question requires an understanding of interspecific competition and how it might affect organisms involved in the competitive relationship. What type of thinking is required? This is an application question; you need to apply your knowledge of character displacement and interspecific competition to determine if the statement is true or false. Gather Content: What do you already know about interspecific competition? What other information is related to the question? Character displacement occurs when a species’ range overlaps with a competitor. Often in areas of sympatry competing species tend to diverge from each other in order to reduce level of competition. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Where two species occur together, they often tend to exhibit character displacement. Character displacement is a result of natural selection. Since evolution acts on genes, it can alter the genotypes and therefore phenotypes of those species in competition Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? You needed to apply your knowledge of character displacement and interspecific competition to decide if the statement is true or false. Were Version 1
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you able to select the correct answer? 2) FALSE
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Clarify question: What is the key concept addressed by the question? The question requires an understanding of interspecific competition and what factors contribute to this type of competition. What type of thinking is required? This is an application question; you need to apply your knowledge of allopatric populations and interspecific competition to determine if the statement is true or false. Gather Content: What do you already know about interspecific competition and the contribution that geographic allopatry might have in establishing the competition? What other information is related to the question? Allopatric populations are geographically isolated from each other. Is competition the only reason why 2 populations may live in completely different areas with no overlap? Choose Answer Given what you now know, what information is most likely to produce the correct answer? When two species do not overlap in space, this could be the result of ecological interactions, but it could also be the result of evolutionary forces. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? You need to apply you knowledge of allopatric populations in order to figure out if the statement is true or false. Although geographic Version 1
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allopatric populations could be the result of competition, other explanations are also possible. 3) FALSE
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Clarify question: What is the key concept addressed by the question? This question requires an understanding of K-selected species and the conditions are associated with those species. What type of thinking is required? This is an application question; you need to apply your knowledge of disturbance and reproductive strategies in order to determine if the statement is true or false. Gather Content: What do you already know about K -selected species? What other information is related to the question? A habitat that experiences a high level of disturbance is not going to be a very stable environment. Are - r or K-selected species going to do better in an unstable environment? r-selected species are typically shortlived, have lots of offspring and provide little or no parental care. Kselected species are typically long-lived organisms that produce a very small number of offspring that receive lots of parental investment. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? r-selected species are species that grow and disperse quickly and reproduce quickly and in large numbers. Therefore, they would be the first species to dominate an area in early succession. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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You needed to apply your knowledge of reproductive strategies to the situation involving a high disturbance environment. Were you able to apply your knowledge about species that are able to adjust to rapidly changing environmental condition and how that relates to r versus Kselected species? 4) TRUE r-selected species are species that grow and disperse quickly and reproduce quickly and in large numbers. Therefore, they would be the first species to dominate an area in early succession. 5) FALSE Resource partitioning occurs when species with similar niches inhabit the same area. Species that inhabit the same area are sympatric. 6) TRUE
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Clarify question: What is the key concept addressed by the question? This question requires an understanding of mimicry and camouflage. What type of thinking is required? This is an evaluate question, you need to examine all of the choices and make a judgement if mimicry is a form of camouflage. Gather Content: What do you already know about mimicry and whether it could be involved with camouflaging? What other information is related to the question? The purpose of camouflage is to hide from a predator. This is achieved by looking like something other than yourself. Typically camouflage is achieved by looking like the surrounding environment. A mimic is a species that looks like a different organism. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Camouflage is a method of concealment that allows otherwise visible animals to remain unnoticed by blending with their environment or by resembling something else. In this way, organisms that can mimic their environment can remain camouflaged. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? You need to use you knowledge of mimicry and camouflage to decide if mimicry is a form of camouflage. Were you able to select the correct Version 1
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answer? 7) [B, C, D, E] 8) [A, B, C, E]
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Clarify question: What is the key concept addressed by the question? The key concepts is identifying examples of secondary succession. What type of thinking is required? This is an application question. You will need to apply your knowledge of ecological succession to determine which scenarios represent secondary succession. This is a check all that apply question, there is more than one correct answer. Gather Content: What do you already know about secondary succession? What other information is related to the question? Ecological succession is the gradual shift in a habitat from one that is colonized with pioneer species to a climax community. When the process is undisturbed it is termed primary succession. Any major disturbance to the habitat stops the process. Once the process restarts it is termed secondary succession. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Farms, landfills, and garden beds have all been drastically altered from a natural state and the costal grasslands damaged by a hurricane has also been altered. In all of these cases, the habitats were not taken to a condition of primary succession. They are examples of secondary succession. Rocks in a national park are undisturbed with pioneering species beginning the succession process. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? You need to apply your knowledge of succession to determine which choices presented phases of secondary succession. Were you able to select the correct answer? 9) [A, B, C, E] 10) [A, B, D, E] 11) [A, B, D]
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Clarify question: What is the key concept addressed by the question? The question requires knowledge about fundamental niches and the factors that affect the fundamental niche. What type of thinking is required? This is an application question. You will need to apply your knowledge of ecological niches to select the correct answers. In this question you need to select all of the factors that could influence the fundamental niche of a particular species. This is a check all that apply question, there is more than 1 correct answer. Gather Content: What do you already know about fundamental niches and what factors influence the niche? What other information is related to the question? The niche is a portion of a particular habitat that is suitable for the species being considered. The fundamental niche represents all of the possible habitats that could be occupied by the species in question without taking other species into account. The realized niche is the actual portion of the habitat where the species is found. The realized niche is always smaller because biotic factors (interactions with other living organisms) restrict the size of the realized niche. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Salinity, soil type, and temperature are all example of factors that influence the fundamental niche. Parasites, predators and commensals would all be factors that could potentially influence the realized niche but not the fundamental niche.
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Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? In this question you needed to apply your knowledge of ecological niches to determine which factors would most likely influence the fundamental niche. Did you understand that some factors might affect a realized niche but not the fundamental niche? 12) [A, D, E] 13) [B, D, E] 14) [C, D] 15) [A, C, D] 16) [A, C, D]
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Clarify question: What is the key concept addressed by the question? The question requires an understanding of coevolution and what type of environmental conditions can contribute to coevolution in the flowers and the hummingbirds that visit them. What type of thinking is required? This is an application question; you need to apply your knowledge of coevolution to determine which features represent evidence of coevolution between the hummingbirds and the flowers. This is a check all that apply type of question, there is more than one correct answer. Gather Content: What do you already know about coevolution? What other information is related to the question? Coevolution occurs when 2 species evolve in lockstep with each other. Coevolution can lead to an “arms race” type of interaction when it occurs between competitors or predator/prey pairings, but it can also be mutually beneficial if the interaction species are in a mutualistic relationship to begin with. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Hummingbird flowers have evolved to attract hummingbirds. They have long tubular flowers that are generally red in color. The flowers, which are generally on stalks, produce a high volume of sugar and nectar since hummingbirds have a high energy requirement. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? You needed to apply your knowledge of coevolution to the situation of the hummingbirds and the flowers they are feeding on. Were you able to identify the characteristics that were similar in the different species flowers and how those characteristics relate to attracting hummingbirds? 17) [C, E]
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Clarify question: What is the key concept addressed by the question? This question requires an understanding of succession and the characteristics of organisms that are better adapted for an environment undergoing succession. What type of thinking is required? This is an evaluate question, you need to examine all of the choices and make a judgement about the suitability of a characteristic to a pioneer species. This is check all that apply question; there is more than one correct answer. Gather Content: What do you already know about succession? What other information is related to the question? An established forest habitat would have large mature trees, low levels of light at the forest floor and very little room for a new species to get started. In a very early succession stage, it would look very different. The habitat would have many smaller plants, high levels of light, and lots of new plant species would be growing and trying to get established. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Pioneer plants would have many characteristics consistent with rselected life history strategies. They would be fast-growing and reproduce in great numbers. They would also be able to germinate and grow in direct sunlight since there would be few other plants to produce shade. They would also likely be wind pollinated as there would not be many animals available for pollination.
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Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? You need to use your knowledge of ecological succession to judge which characteristics would be most beneficial to a pioneer species that is try to establish itself. Did you remember that r-selected species are better able to survive in conditions of succession, like those seen in an establishing forest in the early stages of succession? Knowing that were you able to identify characteristics of r-selected species in a forest succession environment? 18) [C, F]
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Clarify question: What is the key concept addressed by the question? This question requires an understanding of how bacterial diversity is maintained in a community and how bacterial phages may play a role in this diversity. What type of thinking is required? This is an analyze question; you need to break down the question into its components in order to determine the role of phages in communities of bacteria. This is a check all that apply question, there may be more than one correct answer. Gather Content: What do you already know about maintaining bacterial diversity in a community? What other information is related to the question? How could an abundance of viruses be beneficial to maintaining a high level of diversity in a bacterial community? When phages infect bacteria they usually kill the bacteria, which would seem counter to the argument that the phage help maintain bacterial diversity. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Phages are viruses which parasitize bacterial cells. In this situation, the parasites keep any one species of bacteria from becoming dominant which maintains bacterial diversity in the community. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? Version 1
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You need to analyze the question by breaking it down and trying to figure out how having a high level of viruses in an environment help to maintain the bacterial diversity of a community. Did you remember that without predatory pressure on a population, that population can grow unchecked? In that situation, one or two species of bacteria could overtake others and reduce diversity. The phages act as parasites to give many bacterial species a fighting chance and acts to maintain bacterial diversity. 19) A 20) B 21) C 22) D The competitive exclusion principle predicts that one species would be eliminated from that community. 23) B 24) C 25) C 26) A 27) E 28) C 29) C 30) D 31) B 32) A 33) A 34) B 35) A 36) E 37) D 38) A Version 1
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39) A 40) B 41) A 42) B 43) D 44) D 45) D Clarify question: What is the key concept addressed by the question? The key concept is being able to interpret the interaction of two species. What type of thinking is required? This is an analysis question. You will need to extract the information from the graph in order to determine the correct answer. Gather Content: What do you already know about the relationship between the two species? What other information is related to the question? In the situation presented in the question, the Paramecium is the prey and Didinium is the predator. Paramecium is introduced first and the Didinium is introduced later. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? The Didinium increased at the expense of the Paramecium (they were eating them). Once the Paramecium population crashed the Didinium died of starvation. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? You need to extract information from the graph in order to select the correct answer. Were you able to select the correct answer?
46) D
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Clarify question: What is the key concept addressed by the question? The key concept is being able to interpret the interaction of two species. What type of thinking is required? This is an analysis question. You will need to extract the information from the graph in order to determine the correct answer. Gather Content: What do you already know about relationship between the two species? What other information is related to the question? In the situation presented in the question, the population of Paramecium initially increases, once the Didinium is introduced the Paramecium population begins to decline as the Didinium population grows. Once the Paramecium disappears that Didinium disappears shortly afterwards. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Once the Didinium is introduced the Paramecium population begins to decline. This could suggest competition between the two protists for some resource. Once the paramecia are gone the population of Didinium starts to decline. The Didinium were eating the paramecia. Once the paramecia were gone the Didinium starved. Reflection: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? You need to extract information from the graph in order to select the correct answer. Were you able to select the correct answer?
47) B 48) B
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Clarify question: What is the key concept addressed by the question? In this question you are being presented with five situations and you need to determine which one is a commensalistic relationship. What type of thinking is required? This is an application question. You will need to apply your knowledge of symbiotic relationships in order to determine the correct answer. Gather Content: What do you already know about commensalism? What other information is related to the question? Commensalism relationships are where one organism benefits and the other is not affected in any way. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Barnacles hitching a ride on the skin of whales is an example of commensalism. By attaching to the whale skin, the barnacles, which are otherwise sedentary as adults, are able to locate habitats with a better food supply. The whale is not affected by the barnacle. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? You needed to apply your knowledge of symbiotic relationships. Parasitic relationships are often the easiest to identify and the commensalism is less clear because it is sometime difficult to determine that the second organism is not affected by the relationship. Were you able to select the correct answer? Version 1
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49) E
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Clarify question: What is the key concept addressed by the question? The question describes a relationship between a golden jackal and a tiger. What type of thinking is required? This is an application question. You will need to apply your knowledge of symbiotic relationships in order to determine the correct answer. Gather Content: What do you already know about symbiotic relationships? What other information is related to the question? Both partners benefit from a mutualism, whereas one partner benefits and the expense of the other in a parasitism. In a commensalistic relationships one partner benefits and the other is not affected. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? In this relationship, the jackal benefits from the tiger but the tiger neither benefits or is harmed by the relationship. This relationship is an example of commensalism. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? You needed to apply your knowledge of symbiotic relationships to figure out what type of relationships existed between the jackal and the tiger. Were you able to select the correct answer? Version 1
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50) C
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Clarify question: What is the key concept addressed by the question? The question requires a knowledge of different types of symbiotic relationships and in which type of relationship these animals are engaged. What type of thinking is required? This is an application question. You will need to apply your knowledge of symbiotic relationships in order to determine the correct answer. Gather Content: What do you already know about symbiotic relationships how the different behaviors of the animals relate to each type of symbiosis? What other information is related to the question? Both partners benefit from a mutualism, whereas one partner benefits and the expense of the other in a parasitism. In a commensalistic relationships one partner benefits and the other is not affected. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Initially, this was a commensal relationship. The jackal benefited from its relationship with the tiger, but the tiger was unaffected by the jackal. If the jackal assists the tiger in making a kill, both animals benefit. The relationship would then be classified as mutualism. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? You needed to apply your knowledge of symbiotic relationships to figure out which type of relationships existed between the jackal and the Version 1
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tiger. Were you able to correctly identify the previous relationship as commensalism because the tiger wasn't benefiting or hurt by the relationship with the jackal? Did you recognize that the jackal was in fact helping the tiger, which makes it a mutualistic relationship? 51) B
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Clarify question: What is the key concept addressed by the question? The question requires an understanding of different types of symbiotic relationships and identification of relationships based on a descriptions of the associations between different animals. What type of thinking is required? This is an application question, you need to apply your knowledge of symbiotic relationships to situations with cattle egrets and oxpeckers. In this question you need to match the bird (oxpecker or egret) with the type of symbiotic relationship it has with larger grazers. Gather Content: What do you already know about symbiotic relationships and the qualifications for each? What other information is related to the question? Commensalisms are relationships where one benefits and the other is not affected in any way. In a mutualistic relationship both partners benefit from the relationship.Parasitic relationships are where one benefits and the other is harmed by the relationship. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? The egret has a commensalistic relationship, it gets food but the buffalo receives no benefit from the association. The oxpecker has a mutualistic relationship, the bird gets food and the buffalo gets ectoparasites (ex. ticks) removed. Reflection on Process: Did your problem-solving process lead you to the correct answer? If Version 1
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not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? You need to apply your knowledge of symbiosis to the situation. Were you able to recognize if the buffalo benefits in either, both, or neither relationship? In both cases, the birds benefit and so the correct answers depend on being able to determine if the buffalo benefits or not or if it is harmed. 52) A
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Clarify Question What is the key concept addressed by the question? ● The question is asking about an ecological interaction. What type of thinking is required? ● You are being asked to take what you already know and use, or apply, it to a new situation in which species are interacting. Gather Content What do you already know about the interactions between species? What other information is related to the question? ● Interference competition occurs when species have physical interactions over the use of a resource. ● Exploitative competition occurs when two species consume the same resource. ● Intraspecific competition occurs between members of the same species. ● Commensalism is an interaction in which one participant benefits and the other is unaffected. ● Mycorrhizal fungi aid nutrient uptake by their associated plants. Choose Answer Given what you now know, what information is most likely to produce the correct answer? ● The garlic mustard is interfering with the mycorrhizae of the tree, and thereby the ability of the trees ability to take up nutrients, so this is interference competition. Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? ● Answering this question correctly depended on your ability to recognize the ecological interactions in a new situation… If you got an Version 1
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incorrect answer, did you remember that interference competition involves the interactions between species over the use of a resource, or that mycorrhizal aid nutrient absorption? Did you have trouble extending the types of ecological interactions to determine the correct answer? 53) B
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Clarify question: What is the key concept addressed by the question? This question requires an understanding of allopatric and sympatric populations and what conditions lead to each. What type of thinking is required? This is an application question; you need to apply your knowledge of allopatric and sympatric populations to the situation of hummingbirds. Gather Content: What do you already know about allopatric and sympatric populations of organisms? What other information is related to the question? Allopatric populations are geographically isolated from each other, whereas sympatric populations occur in the same area. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Following breeding season, these species are sympatric, because they are occupying the same geographic area. Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? You need to apply your knowledge of sympatry and allopatry to determine which applied to the populations following the breeding season. Did you remember that sympatric populations occur in the same area and the defining characteristic of allopatric populations are they that they are separated? Did you think the coevolution of the flowers was Version 1
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important in answering the question? 54) A
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Clarify question: What is the key concept addressed by the question? This question requires an understanding of environmental pressures and whether the presence of phages is a density-dependent or densityindependent factor the help to regulate the bacterial community. What type of thinking is required? This is an evaluate question; you need to evaluate the impact of phages on the diversity of the bacterial community. Gather Content: What do you already know about density-dependent versus densityindependent factors affecting a community? What other information is related to the question? Phages are viruses which parasitize bacterial cells. In this situation, the parasites keep any one species of bacteria from becoming dominant which maintains diversity within the community. The effect of the phages on any particular species of bacteria can vary with size of the population of the particular bacteria. At a low population size, the virus will spread slowly and have a small effect on the bacteria. If the population of bacteria is particularly high, the virus (phage) can spread quickly through the population and have a huge effect. Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Phages are parasites and parasites move between members of a species faster when population numbers are high. This makes them densitydependent regulators. Parasites play an important role in maintaining bacterial community diversity because they prevent any one species of bacteria from becoming dominant.
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Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? To answer this question you had to ignore certain information in the question to focus on the issue of density-dependent versus densityindependent control of populations. The fact that phages help to maintain bacterial diversity is important, but the question if the phage infection is density-dependent or density-independent relates more to whether the size of the bacterial population affect phage infections. Larger populations of bacteria allow phage infections to spread faster, making phages a density-dependent factor. 55) A
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Chapter 56 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) Solar energy is the same thing as heat energy. ⊚ ⊚
true false
CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 2) In which of the following ways does species richness affect ecosystem function? Check all that apply. A) Low species richness can contribute to ecosystem stability. B) High species richness can increase ecosystem resistance to drought. C) Low species richness can make an ecosystem more susceptible to invasive species. D) High species richness reduces overall ecosystem productivity.
3)
Which of the following are true about ecosystems? Check all that apply. A) They contain both living and nonliving components. B) There is a transfer of energy through the system and some energy is lost as heat
energy. C) Nutrients repeatedly cycle through the ecosystem. D) They represent the lowest level of biological organization. E) The ultimate source of energy for most ecosystems is the sun.
4)
Which of the following are true statements about the carbon cycle? Check all that apply.
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A) Carbon and nitrogenfixation are both facilitated by microbes. B) Burning of gasoline is a contributor to the current imbalance in the carbon cycle. C) Replacing rainforest with farms decreases atmospheric CO2 levels. D) In water, inorganic carbon exists in two different forms, both of which can be used by autotrophs. E) Carbon cycles locally.
5) Which one of the following statements about the trophic cascade in the sea otter and sea urchin-kelp communities along the West Coast of North America are true? Check all that apply. A) Increased sea otter populations are linked to more profuse growth of the kelp forests. B) Increased orca (killer whale) predation on sea otters is linked to more profuse growth of the kelp forests. C) Increased sea otter populations are linked to increased sea urchin populations. D) Increased orca (killer whale) predation on sea otters is linked to increased sea urchin populations. E) Increased sea urchin populations are linked to less profuse growth of the kelp forests.
6) Phosphorus deficiency often appears early in plant growth and results in stunting. Which of the following are reasons why a deficiency in phosphorus would cause growth abnormalities in plants? (Check all that apply.) A) Phosphorus is required for the storage and transfer of energy. B) Phosphorus is required for the production of amino acids that form proteins. C) Phosphorus is required for DNA replication. D) Phosphorus is necessary for building moleculesin the cell membrane. E) Without phosphorus, cellular replication is impeded.
7) Which of the following hypotheses support the basic principle of the species-area relationship? Check all that apply.
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A) Large areas have greater habitat diversity than small areas. B) Organisms are less likely to go extinct in larger areas than smaller areas. C) Larger areas receive more colonists than smaller areas. D) Smaller areas have greater concentrations of resources then larger areas.
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 8) Which of the following is a producer? A) pine tree B) cricket C) mushroom D) rabbit E) red-tailed hawk F) earthworm
9) A ____________ cycle is a cyclic path that involves both biological and chemical processes of an ecosystem. A) biogeochemical B) complete C) hydrological D) complementary
10) A(n) ________ is a permeable underground layer of rock, sand, and gravel saturated with groundwater. A) natural spring B) aquifer C) hot spring D) submergence
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11) The upper, unconfined portion of the groundwater constitutes the ____, which flows into streams and is partly accessible to plants. A) aquifer B) hydrozone C) water table D) watershed
12)
Heterotrophs must obtain organic molecules that have been synthesized by A) biogeochemical cycles. B) bacteria. C) decomposers. D) autotrophs.
13) NPP is the difference between plant photosynthesis and respiration. Therefore, NPP quantifies the net absorption of what element(s) by living plants? A) carbon B) phosphorus C) nitrogen D) oxygen E) nitrogen, phosphorus, and potassium
14)
A wolf that feeds on moose and elk would be classified within which trophic level? A) herbivore B) primary producer C) primary carnivore D) secondary carnivore E) detritivore
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15)
Only about ____ of the sunlight falling on plant leaves is captured by photosynthesis. A) 1% B) 10% C) 25% D) 50%
16)
Which of the following atmospheric gases is changing the global climate? A) ozone B) water vapor C) carbon dioxide D) hydrogen E) oxygen
17) The honey possum ( Tarsipes rostratus) is a tiny Australian marsupial that feeds entirely on nectar. Which of the following terms describes the role of a honey possum in its ecosystem? A) herbivore B) primary producer C) primary carnivore D) secondary carnivore E) detritivore
18) Vampire squid ( Vampyroteuthisinfernalis) are deep-sea cephalopods with features similar to both octopus and squid. Extensive video recordings show the diet of the vampire squid consists of items like crustacean remains and fecal pellets. Which of the following terms describes the position of the vampire squid in the deep-sea trophic pyramid?
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A) herbivore B) primary producer C) primary carnivore D) secondary carnivore E) detritivore
19) Over tropical rainforest areas, approximately 90% of the water that reaches the atmosphere comes from A) animal metabolism. B) animal perspiration. C) plant transpiration. D) plant absorption. E) plant metabolism.
20) In the carbon cycle, ______ from the atmosphere is used in photosynthesis to synthesize carbon-containing organic molecules in a process called ______.
A) carbon dioxide; combustion B) carbon dioxide; carbon fixation C) hydrocarbons; oxidation D) hydrocarbons; cellular respiration
21) Even though nitrogen constitutes 78% of Earth's atmosphere, the amount available for living things nearly all comes from A) a few groups of nitrogen-fixing bacteria. B) the breakdown of minerals. C) a few genera of detritivores. D) the breakdown of dead plants. E) nitrogen-containing fertilizers.
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22)
With almost no exceptions, the nitrogen fixers are A) beans. B) green plants. C) insects. D) mammals. E) prokaryotes.
23)
The form of nitrogen most likely to be absorbed from the soil by plants is A) nitrogenous wastes. B) nucleic acids. C) nitrogen gas. D) nitrous oxide gas. E) nitrite/nitrate ions.
24)
Which of the following biogeochemical cycles contain a mineral component? A) phosphorus B) carbon C) nitrogen D) oxygen E) water
25)
The scarcity of which two elements limits plant growth? A) oxygen, nitrogen B) nitrogen, phosphorus C) oxygen, phosphorus D) carbon, nitrogen E) carbon, phosphorus
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26)
Which of the following groups do not contain any species that are autotrophs? A) Bacteria B) Protista C) Plants D) Archaea E) Fungi
27)
Energy enters most ecosystems by the process of A) biosynthesis. B) respiration. C) biogeochemical weathering. D) photosynthesis. E) fermentation.
28)
The net weight of all of the organisms living in an ecosystem is its A) productivity. B) biomass. C) vital force. D) photosynthesis minus metabolism. E) combined output of metabolism and photosynthesis.
29) In an ecosystem, the amount of organic matter produced in a given time that is available for heterotrophs is known as A) daily yield. B) gross primary productivity. C) net primary productivity. D) effective vitality. E) net yield.
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30) A good average value for the amount of energy that reaches the next trophic level is about A) 20%. B) 10%. C) 5%. D) 2%. E) 1%.
31)
The rate of production of new biomass by heterotrophs is called A) secondary productivity. B) primary productivity. C) consumer productivity. D) gross productivity. E) net productivity.
32) Which one of the following factors would NOT influence the productivity of an ocean community? A) the presence of nitrogen-fixing cyanobacteria B) the season of the year C) levels of autotrophs D) fertilizer runoff E) the amount of rainfall
33)
In an ecosystem
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A) both energy and nutrients cycle. B) energy flows and nutrients cycle. C) energy cycles and nutrients flow. D) both energy and nutrients flow. E) energy is contained with nutrient cycles.
34) During the 1960s, a group of scientists in the northeastern United States conducted an experiment at Hubbard Brook, New Hampshire. A 38-acre watershed was completely deforested and the runoff (water flow) monitored for several years. It was compared to an adjacent watershed that was left untouched. The scientists collected data during those years and found A) no difference in the amount of runoff from the two areas. B) an insignificant difference in the amount of nitrogen from the two areas. C) a tremendous increase in the total amount of runoff from Hubbard Brook although the loss of nitrogen was fairly consistent in both areas. D) a tremendous increase in the amount of runoff and nitrogen release from Hubbard Brook compared to the control.
35) In the food chain below, what does the blue jay represent? crabgrass—cricket—garden spider—blue jay—red-tailed hawk A) herbivore B) primary producer C) primary carnivore D) secondary carnivore E) detritivore
36) In the food chain below, what does the garden spider represent? crabgrass—cricket—garden spider—blue jay—red-tailed hawk
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A) herbivore B) primary producer C) primary carnivore D) secondary carnivore E) detritivore
37) A Viceroy caterpillar feeds on a leaf. One day's feeding consumes 1000 calories worth of leaves. 50% of the calories are lost in its feces and 33% of the calories are used in cellular respiration.How many calories of the original intake are available to add to the caterpillar’s biomass each day? A) 830 calories B) 670 calories C) 500 calories D) 330 calories E) 170 calories
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38) The following figure shows studies in a stream where enclosures were set up either with trout or with no trout. Which statement is a correct interpretation of the graph about trout, invertebrates, and algae?
A) If trout are present in a system, algae production is low and invertebrate population levels are also low. B) If trout are present in a system, algae production is high and invertebrate population levels are also high. C) If trout are present in a system, algae production is high and invertebrate population levels are low. D) Trout do not seem to affect the algae production; only the invertebrate populations are affected. E) Trout do affect the algae production but not the invertebrate populations.
39) Which one of the following ecosystems is most likely to show an inverted biomass pyramid but a normal energy pyramid?
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A) grassland B) open ocean C) intertidal D) tropical forest E) desert
40) Which one of the following quantities best represents the respiratory heat lost by plants in an ecosystem? A) gross primary productivity B) net primary productivity C) gross primary productivity - net primary productivity D) gross primary productivity - standing crop biomass E) gross primary productivity - secondary productivity
41) In a food chain with four trophic levels, what would be the energy in the top trophic level if the energy contained in the primary producer level is 40,000 kcal/m2/yr? Assume a trophic level transfer efficiency of 10%. A) 4,000 kcal/m2/yr B) 400 kcal/m2/yr C) 40 kcal/m2/yr D) 4 kcal/m2/yr E) 0.4 kcal/m2/yr
42) In a marine ecosystem with an inverted biomass pyramid, which trophic level should have the smallest number of organisms?
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A) phytoplankton B) zooplankton C) primary carnivores (sardines) D) secondary carnivores (tuna) E) detritivores
43) Addition of a primary carnivore to an ecosystem can sometimes influence the whole ecosystem. This process is called A) ecosystem stabilization. B) a bottom-up effect. C) species turnover. D) disruption. E) a trophic cascade.
44) According to MacArthur and Wilson's island biogeography theory, which of the following would be expected to have the smallest species richness? A) the mainland B) a large island near the mainland C) a large island far from the mainland D) a small island near the mainland E) a small island far from the mainland
45) The tropics are known to have greater species diversity than the temperate zones.Which explanation for this phenomenon is the LEAST convincing?
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A) Seasonal variability is less in the tropics. B) Niches are narrower in the tropics. C) Fewer predators in the tropics allow more prey species to flourish. D) Greater spatial heterogeneity in the tropics creates more niches. E) The tropics have greater plant production, which supports greater overall species richness.
46) In an aquatic ecosystem, a secondary carnivore is temporarily excluded and then, after a period of time, is returned. Which one of the following is NOT an expected top-down effect after it is returned? A) Primary carnivores become less abundant. B) Primary productivity increases. C) Algae decrease. D) Herbivores become more abundant.
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Answer Key Test name: Chap 56_13e_Raven 1) FALSE Both solar energy and heat are forms of energy, but solar energy is organized and can be captured and converted and used to drive cellular work. Heat energy is a by-product of energy conversions and is a disorganized form of energy that cannot be used to power cellular processes. 2) [B, C] 3) [A, B, C, E] 4) [A, B, D] 5) [A, D, E] 6) [A, C, D, E]
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Clarify Question • What is the key concept addressed by the question? o This question addresses the phosphorus cycle. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about the phosphorus cycle? o Phosphorus is found in ATP, the energy carrier of the cell. o Phosphorus is found in the phosphate backbone of DNA and RNA. o Phosphorus is found in phospholipids of the cell membrane. o However, phosphorus is not found in amino acids or proteins. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Phosphorus is an essential plant nutrient for many reasons. Phosphorus is necessary to the metabolism of a plant because it is part of ATP which stores and transfers energy within cells. Phosphorus is found in phospholipids that comprise the majority of the cellular membranes and in the bonds that hold nucleotides together in a DNA molecule. Without phosphorus, cell division would be negatively affected because division requires DNA synthesis and membrane formation. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can Version 1
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you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that phosphorus is important for plants because it is in ATP, DNA, and phospholipids? 7) [A, B, C]
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Clarify Question • What is the key concept addressed by the question? o This question addresses species richness. • What type of thinking is required? o This question is asking youto weigh and judge evidence, or evaluate, to choose the best of the possible answers. Gather Content • What do you already know about species richness? o The species-area relationship states that larger islands contain more species than do smaller islands. Several hypotheses have been proposed to explain this relationship. o First, larger areas have more habitat diversity and therefore harbor mores species (the habitat diversity hypothesis). o The second hypothesis states that species persist longer in larger habitats (the area per se hypothesis). o The third hypothesis states that larger areas are more likely to receive more colonists representing a greater diversity of organisms (the passive sampling hypothesis). o Finally, the resource-concentration hypothesis states that larger areas have more abundant resources and therefore will support a greater number of species. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Do large areas have greater habitat diversity than small areas? Yes. o Are organisms less likely to go extinct in larger areas than smaller areas? Yes. Version 1
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o Do larger areas receive more colonists than smaller areas? Yes. o Do smaller areas have greater concentrations of resources then larger areas? No! Larger areas are likely to have more resources. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. o Did you recognize that larger areas tend to support more species for several reasons? 8) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses trophic levels. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about trophic levels? o The first trophic level in an ecosystem, called the primary producers, consists of all the autotrophs in the system. These are usually photosynthetic organisms – plants, algae and cyanobacteria. At deep sea vents, however, the primary producers are chemosynthetic microbes. o The other trophic levels consist of the heterotrophs—the consumers. All the heterotrophs that feed directly on the primary producers are placed together in a trophic level called the herbivores. o In turn, the heterotrophs that feed on the herbivores (eating them or being parasitic on them) are collectively termed primary carnivores, and those that feed on the primary carnivores are called secondary carnivores. o An additional consumer level is the detritivore trophic level. Detritivores feed on the remains of already dead organisms. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o A producer in an ecosystem is nearly always photosynthetic (except for a few chemoautotrophic prokaryotes such as those near deep sea vents). Version 1
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o The only photosynthetic organism as an option was the pine tree. Any plant is a primary producer. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that producers are nearly always plants, algae, or cyanobacteria? 9) A 10) B 11) C 12) D 13) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses productivity. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about productivity? o The productivity of a trophic level is the rate at which the organisms in the trophic level collectively synthesize new organic matter in their tissues. o Primary productivity is the productivity of the primary producers. An important complexity in analyzing the primary producers is that not only do they synthesize new organic matter by photosynthesis, but they also break down some of the organic matter to release energy by means of aerobic cellular respiration. The respiration of the primary producers, in this context, is the rate at which they break down organic compounds. o Gross primary productivity (GPP) is simply the raw rate at which the primary producers synthesize new organic matter; net primary productivity (NPP) is the GPP minus the respiration of the primary producers. The NPP represents the organic matter available for herbivores to use as food. o The productivity of a heterotroph trophic level is termed secondary productivity. For instance, the rate that new organic matter is made by means of individual growth and reproduction in all the herbivores in an ecosystem is the secondary productivity of the herbivore trophic level. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o NPP quantifies the net carbon absorption rate by living plants. NPP is the difference between plant photosynthesis, which fixes atmospheric CO2 into sugars and other organic molecules, and respiration, which combusts sugar and releases the carbon back into the atmosphere. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that NPP is net primary productivity – the net absorption of carbon by plants? 14) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses trophic levels. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about trophic levels? o The first trophic level in an ecosystem, called the primary producers, consists of all the autotrophs in the system. These are usually photosynthetic organisms – plants, algae and cyanobacteria. At deep sea vents, however, the primary producers are chemosynthetic microbes. o The other trophic levels consist of the heterotrophs—the consumers. All the heterotrophs that feed directly on the primary producers are placed together in a trophic level called the herbivores. o In turn, the heterotrophs that feed on the herbivores (eating them or being parasitic on them) are collectively termed primary carnivores, and those that feed on the primary carnivores are called secondary carnivores. o An additional consumer level is the detritivore trophic level. Detritivores feed on the remains of already dead organisms. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The wolf is not a plant, so it is not a producer. o The wolf does not eat plants, so it is not an herbivore. o The wolf does not eat things that are already dead, so it is not a Version 1
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detritivore. o The wolf eats mostly herbivories, not carnivores. That makes it a primary carnivore. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that a wolf is an example of a primary carnivore? 15) A 16) C 17) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses trophic levels. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about trophic levels? o The first trophic level in an ecosystem, called the primary producers, consists of all the autotrophs in the system. These are usually photosynthetic organisms – plants, algae and cyanobacteria. At deep sea vents, however, the primary producers are chemosynthetic microbes. o The other trophic levels consist of the heterotrophs—the consumers. All the heterotrophs that feed directly on the primary producers are placed together in a trophic level called the herbivores. o In turn, the heterotrophs that feed on the herbivores (eating them or being parasitic on them) are collectively termed primary carnivores, and those that feed on the primary carnivores are called secondary carnivores. o An additional consumer level is the detritivore trophic level. Detritivores feed on the remains of already dead organisms. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Since the honey possum eats nectar, which is the sweet liquid produced in flowers, it is a plant-eater or herbivore.
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that some herbivories don’t eat leaves, but eat other parts of a plant? 18) E
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Clarify Question • What is the key concept addressed by the question? o This question addresses trophic levels. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about trophic levels? o The first trophic level in an ecosystem, called the primary producers, consists of all the autotrophs in the system. These are usually photosynthetic organisms – plants, algae and cyanobacteria. At deep sea vents, however, the primary producers are chemosynthetic microbes. o The other trophic levels consist of the heterotrophs—the consumers. All the heterotrophs that feed directly on the primary producers are placed together in a trophic level called the herbivores. o In turn, the heterotrophs that feed on the herbivores (eating them or being parasitic on them) are collectively termed primary carnivores, and those that feed on the primary carnivores are called secondary carnivores. o An additional consumer level is the detritivore trophic level. Detritivores feed on the remains of already dead organisms. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Since the vampire squid feed on bits of dead organic matter, that makes them detritivores.
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that detritivores are organisms that feed on dead organic matter? 19) C 20) B 21) A 22) E 23) E 24) A 25) B 26) E 27) D 28) B 29) C 30) B 31) A 32) E
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Clarify Question • What is the key concept addressed by the question? o This question addresses productivity. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content • What do you already know about productivity? o The productivity of a trophic level is the rate at which the organisms in the trophic level collectively synthesize new organic matter in their tissues. o Primary productivity is the productivity of the primary producers. An important complexity in analyzing the primary producers is that not only do they synthesize new organic matter by photosynthesis, but they also break down some of the organic matter to release energy by means of aerobic cellular respiration. The respiration of the primary producers, in this context, is the rate at which they break down organic compounds. o Gross primary productivity (GPP) is simply the raw rate at which the primary producers synthesize new organic matter; net primary productivity (NPP) is the GPP minus the respiration of the primary producers. The NPP represents the organic matter available for herbivores to use as food. o The productivity of a heterotroph trophic level is termed secondary productivity. For instance, the rate that new organic matter is made by means of individual growth and reproduction in all the herbivores in an ecosystem is the secondary productivity of the herbivore trophic level. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Since production is the amount of carbon fixed by the photosynthetic activity of plants, algae, and cyanobacteria, factors that increase their success increase production. For instance, nutrient availability from fertilizer or from nitrogen-fixing bacteria, or increased sunlight during the summer, will increase production. o On land, rainfall can also promote production. But in the ocean, this factor is likely to have little effect. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that many factors can influence the productivity of an ecosystem? 33) B 34) D 35) D
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Clarify Question • What is the key concept addressed by the question? o This question addresses trophic levels. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about trophic levels? o The first trophic level in an ecosystem, called the primary producers, consists of all the autotrophs in the system. These are usually photosynthetic organisms – plants, algae and cyanobacteria. At deep sea vents, however, the primary producers are chemosynthetic microbes. o The other trophic levels consist of the heterotrophs—the consumers. All the heterotrophs that feed directly on the primary producers are placed together in a trophic level called the herbivores. o In turn, the heterotrophs that feed on the herbivores (eating them or being parasitic on them) are collectively termed primary carnivores, and those that feed on the primary carnivores are called secondary carnivores. o An additional consumer level is the detritivore trophic level. Detritivores feed on the remains of already dead organisms. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o In this food chain, the blue jay feeds mainly on spiders, the primary carnivore. Therefore the jays are the secondary carnivore.
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that there are often multiple levels of carnivores in a food chain? 36) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses trophic levels. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about trophic levels? o The first trophic level in an ecosystem, called the primary producers, consists of all the autotrophs in the system. These are usually photosynthetic organisms – plants, algae and cyanobacteria. At deep sea vents, however, the primary producers are chemosynthetic microbes. o The other trophic levels consist of the heterotrophs—the consumers. All the heterotrophs that feed directly on the primary producers are placed together in a trophic level called the herbivores. o In turn, the heterotrophs that feed on the herbivores (eating them or being parasitic on them) are collectively termed primary carnivores, and those that feed on the primary carnivores are called secondary carnivores. o An additional consumer level is the detritivore trophic level. Detritivores feed on the remains of already dead organisms. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Since the spiders are feeding on crickets, which are herbivores, the spiders are the primary carnivore.
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that invertebrates that eat meat are also called carnivores? 37) E
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Clarify Question • What is the key concept addressed by the question? o This question addresses energy flow. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content • What do you already know about energy flow? o Energy flow between trophic levels is inefficient. Whenever organisms use chemical-bond or light energy, some of it is converted to heat. Consistent with the Second Law of Thermodynamics, a partial conversion to heat is inevitable. Put another way, animals and plants require chemical-bond energy and light to stay alive, but as they use these forms of energy, they convert them to heat, which they cannot use to stay alive and which they cannot cycle back into the original forms. Fortunately for organisms, the Earth functions as an open system for energy, because light arrives every day from the Sun. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o One day's feeding consumes 1000 calories worth of leaves. o 50% of the calories are lost in its feces – so 500 calories are lost just due to inefficient digestion. o 33% of the calories are used in cellular respiration – so 330 calories are used to keep the caterpillar alive. o 1000 – 500 – 330 = 170 calories o So only 170 calories are available to add to the caterpillar’s biomass Version 1
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each day. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that most of the energy from food is lost or used to support respiration? 38) C 39) B 40) C 41) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses energy flow. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content • What do you already know about energy flow? o Energy flow between trophic levels is inefficient. Whenever organisms use chemical-bond or light energy, some of it is converted to heat. Consistent with the Second Law of Thermodynamics, a partial conversion to heat is inevitable. Put another way, animals and plants require chemical-bond energy and light to stay alive, but as they use these forms of energy, they convert them to heat, which they cannot use to stay alive and which they cannot cycle back into the original forms. Fortunately for organisms, the Earth functions as an open system for energy, because light arrives every day from the Sun. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The food chain has four trophic levels: primary producer, herbivore, primary carnivore, and secondary carnivore. o The primary producer level (level 1) has 40,000 kcal/m2/yr. o If transfer efficiency is 10%, then the herbivore level (level 2) will have 10% of 40,000, or 4,000kcal/m2/yr. o The primary carnivore level (level 3) will have 10% of 4,000, or 400 kcal/m2/yr. Version 1
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o The secondary carnivore level (level 4) will have 10% of 400, or 40 kcal/m2/yr. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that energy is lost between each trophic level of a food chain? 42) A 43) E 44) E 45) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses species richness. • What type of thinking is required? o This question is asking youto weigh and judge evidence, or evaluate, to choose the best of the possible answers. Gather Content • What do you already know about species richness? o Species richness is the number of species present in a community.Species richness is influenced by ecosystem characteristics, including primary productivity, habitat heterogeneity, and climate factors. o Tropical regions have the highest diversity, although the reasons are unclear. Reasonable explanations include the following: o The tropics have existed over long, uninterrupted periods of evolutionary time, whereas temperate regions have been subject to repeated glaciations. The greater age of tropical communities would have allowed complex population interactions to coevolve within them, fostering a greater variety of plants and animals. o The tropics receive more solar radiation than do temperate regions. The argument is that more solar energy, coupled to a year-round growing season, greatly increases the overall photosynthetic activity of tropical plants. o Seasonal variation, though it does exist in the tropics, is generally substantially less than in temperate areas. This reduced seasonality might encourage specialization, with niches subdivided to partition resources and so avoid competition. The expected result would be a larger number of more specialized species in the tropics. Version 1
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o Predation is more intense in the tropics. In theory, more intense predation could reduce the importance of competition, permitting greater niche overlap and thus promoting greater species richness. o Spatial heterogeneity promotes species richness. Tropical forests, by virtue of their complexity, create a variety of microhabitats and so may foster larger numbers of species. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Is seasonal variability less in the tropics? Yes. This may foster species diversity. o Are niches narrower in the tropics? Yes. This may foster species diversity. o Could greater spatial heterogeneity in the tropics create more niches? o Do the tropics have greater plant production, which supports greater overall species richness? Yes. o Are there fewer predators in the tropics, allowing more prey species to flourish? No. In fact, predation is thought to be more intense in the tropics. So this is the worst explanation. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. o Did you recognize that the tropics have high species diversity for several reasons? These include high primary productivity, less extreme Version 1
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seasonal changes, and a large number of specific niches. 46) B
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Clarify Question • What is the key concept addressed by the question? o This question addresses trophic cascades. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content • What do you already know about trophic cascades? o Because of food chain interactions, species in any one trophic level may have effects on more than one trophic level. o Primary carnivoresmay have effects not only on the animals they eat, but also, indirectly, on the plants or algae eaten by their prey. The process by which effects exerted at an upper trophic level flow down to influence two or more lower levels is termed a trophic cascade. The effects themselves are called top-down effects. o Conversely, increases in primary productivity may provide more food not just to herbivores, but also, indirectly, to carnivores. When an effect flows up through a trophic chain, such as from primary producers to higher trophic levels, it is termed a bottom-up effect. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o After returning a secondary carnivore to an ecosystem, would you expect primary carnivores to become less abundant? Yes. This is a reasonable prediction because the secondary carnivores would eat the primary carnivores. o After returning a secondary carnivore to an ecosystem, would you Version 1
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expect that herbivores would become more abundant.? Yes. This is a reasonable prediction, because more secondary carnivores would mean fewer primary carnivores, which would mean more herbivores. o After returning a secondary carnivore to an ecosystem, would you expect algae to decrease? Yes. This is a reasonable prediction, because more secondary carnivores would mean fewer primary carnivores, which would mean more herbivores, which would eat the algae. o After returning a secondary carnivore to an ecosystem, would you expect primary productivity to increase? No. With more secondary carnivores, fewer primary carnivores, more herbivores eating plants and algae, you would expect productivity to DECREASE, not increase. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that changing the numbers of individuals at a high trophic level can have top-down effects all the way down the food chain? o How might this phenomenon influence conservation efforts?
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Chapter 57 13e TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) If the tilt of Earth's axis relative to its plane of orbit was increased to 30 degrees, the seasons in Boston, Massachusetts would become less distinct. ⊚ ⊚
true false
2) An old farm that has been abandoned for 65 years is being sold to develop the land for housing. You attend a town meeting and describe this as a bad idea. Your evidence to support this claim relates to the removal of trees to build the homes. You tell the crowd that removal of the trees will limit the number of predators in the area, and therefore allow the local mouse population to increase, and with the mice, an increase in disease. Is basis of your argument true or false? ⊚ ⊚
true false
CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 3) Which of the following are characteristics of biomes? Check all that apply. A) A biome is a large geographical area with distinctive plant and animal groups. B) Biomes are only located at certain longitudes and latitudes. C) The climate and geography of a region determines what type of biome can exist in that region. D) Each biome consists of only one type of ecosystem. E) Temperate evergreen forest is one of the major biomes.
4) The distribution of biomes is dependent upon which of the following? Check all that apply.
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A) available moisture B) temperature C) the presence of mountains D) distance from the oceans and elevation E) a thermocline
5) Which of the following human activities could contribute to the eutrophication of a lake? Check all that apply. A) dumping piles of leaves near a lake B) planting trees around the periphery of the lake C) washing clothes with soap in the lake D) feeding the ducks in the lake E) dumping plastic trash into the lake F) fertilizing lawns near the lake
6)
Which of the following statements about El Niño are true?
A) Occurrence of ElNiño is irregular and unpredictable. B) The immediateeffect of El Niño is a weakening in the east-to-west trade winds C) Weakening in the trade winds results in more upwelling along the Peru-Ecuador coast. D) El Niño results inthe movement of weather systems from the western Pacific eastward. E) El Niño events inthe Pacific can influence weather as far away as Africa.
7)
Which statements about acid precipitation are accurate? Check all that apply.
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A) Acid rain is intermediate between point-source and diffuse pollution. B) Mercury is a pollutant that often accompanies acid precipitation. C) Acid precipitation is a severe problem in areas with soils having high buffering capacity. D) Acid precipitation can affect aquatic ecosystems. E) Acid precipitation can affect forests, weakening the trees and making them more susceptible to disease.
8)
Which of the following statements about ozone depletion are true? Check all that apply. A) Concentrations of ozone-depleting chemicals continue to rise in the atmosphere. B) Chlorofluorocarbons (CFCs) are the major cause of ozone depletion. C) Free chlorine in the upper atmosphere catalyzes the conversion of O3 into O2. D) Weather conditions also influence the size of the ozone hole in the stratosphere. E) CFCs are acted on by conditions in the stratosphere to form diatomic chlorine (Cl2).
9) Which of following statements about the causes and effects of global warming are accurate? Check all that apply.
A) Theeffects of global warming will be uniform throughout the world. B) In addition to carbon dioxide, other greenhouse gases include methane and nitrous oxide. C) Melting of the Artic permafrost will slow the process of global warming because of new plant growth in those areas. D) The effects of global warming can be measured today. E) Carbon dioxide absorbs short wavelength radiant energy better than long wavelength radiant energy.
10) Which of the following statements about the consequences of global warming are true? Check all that apply.
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A) The rate of global warming may be too great for populations to be able to adapt through natural selection. B) Rising sea levels will be a consequence of global warming. C) Global warming will cause a decrease in the incidence of diseases caused by mosquitoes. D) The frequency ofEl Niño events may increase as a consequence of global warming. E) Agricultural production will increase.
11) Which of the following statements about the effects of deforestation on terrestrial ecosystems are true? Check all that apply. A) At present rates of deforestation, it is predicted that all of the world's tropical rain forests will be degraded or gone within 10 years. B) Today, deforestation is one of the greatest problems facing terrestrial ecosystems. C) Deforestation usually leads to the overaccumulation of nutrients such as nitrates/nitrites in the soil. D) Deforestation can lead to loss of topsoil. E) Deforestation can lead to eutrophication of aquatic ecosystems.
12) Your biology professor takes the class on a field trip to a local lake. You spend an hour studying the lake and writing down all observations. You hypothesize that the lake is oligotrophic. Which observations would support this hypothesis? Check all that apply. A) The shoreline is mostly rock and sand with very little vegetative matter. B) The lake has extensive aquatic plant beds. C) The lake has little planktonic growth. D) The bottom of the lake is easily visible. E) An oxygen probe reveals low oxygen content in the water.
13)
Which of the following are examples of diffuse pollution? Check all that apply.
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A) chemicals released from a factory waste pipe B) wind-borne debris blowing out to sea C) pet waste D) oil leaking from a cargo ship E) oil that washes off of roads
MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 14) To increase the sockeye salmon ( Oncorhynchus nerka) population in three coastal lakes, researchers in Alaska treated ponds with fertilizers. This increased the zooplankton biomass between 40% and 700% in the three lakes. The substantial growth in zooplankton would suggest that prior to these experiments, these lakes were __________________. A) eutrophic B) stratified C) subject to low light levels D) oligotrophic
15) If the energy of the sun no longer reached Earth, the primary productivity of which of the following ecosystems would be least affected? A) deep sea hydrothermal vent B) temperate rain forest C) desert D) taiga E) coral reef
16) While visiting the South Island of New Zealand, you notice that conditions vary sharply across the island. The West Coast is very wet and receives between 600 and 1600 mm of rainfall per year, while the East Coast only receives about 640 mm of rain per year and is very dry. What best explains this regional difference in precipitation?
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A) Proximity to Antarctica. B) The absence of inland lakes. C) The presence of a large river along the West Coast. D) The presence of mountains along the West Coast. E) Latitudinal differences between the East and West Coasts.
17) The great deserts and associated arid areas of the world mostly lie along the western sides of the continents at about A) 0° north and south latitude. B) 15° north and south latitude. C) 30° north and south latitude. D) 60° north and south latitude. E) 90° north and south latitude.
18) Drifting freely in the upper, well-illuminated waters of the ocean, a diverse biological community exists, primarily consisting of microscopic organisms called A) phytoplankton. B) archaeans. C) detritus. D) benthos. E) bacteria.
19)
Most of the ultraviolet radiation reaching the upper atmosphere is absorbed by A) CFCs. B) ozone. C) nitrogen. D) carbon dioxide. E) water vapor.
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20) Periodic disturbances of the Pacific currents that cause global weather changes are given the name A) El Niño. B) gyrals. C) the Humboldt current. D) the Japan current. E) west equatorial drift.
21)
Photosynthetic organisms of the open oceans are confined to the upper A) two hundred millimeters. B) two hundred centimeters. C) two hundred meters. D) two hundred kilometers. E) two thousand kilometers.
22) The relatively shallow part of the ocean extending from the low tide mark to the edge of the continental shelf is called the A) surface zone. B) abyssal zone. C) neritic zone. D) littoral zone. E) limnetic zone.
23) During an ecology field trip to a lake, your professor asks you to take temperature readings at various depths and record your data. At 5 meters, you note a temperature of 25°C and at 10 meters you record a temperature of 10°C. Readings at 20 meters and below stay fairly consistent around 8°C. The temperature readings of 25°C, 10°C, and 8°C represent the
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A) epilimnion, thermocline, and hypolimnion. B) epilimnion, hypolimnion, and thermocline. C) hypolimnion, epilimnion, and thermocline. D) hypolimnion, thermoc line, and epilimnion. E) thermocline, epilimnion, and hypolimnion.
24)
Destruction of which biome would result in the greatest loss of biodiversity? A) desert B) grassland C) savanna D) taiga forest E) tropical rain forest
25)
Prairie is another name for a A) desert. B) temperate grassland. C) savanna. D) taiga. E) tundra.
26) Rhizosphaera needle cast is a fungal disease that affects spruce trees. Which of the following biomes would be most severely affected by an outbreak of this disease? A) tundra B) temperate deciduous forest C) prairie D) taiga E) tropical rain forest
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27)
Tropical climates are warmer than temperate climates because
A) temperate climates have more mountains and thus more snow causing the landmasses to warm slower. B) tropical climates have more vegetation and thus can absorb more heat. C) temperate climates are closer to the poles and the polar surfaces cause a reduction in heat gain. D) tropical climates receive the sun's rays at an almost perpendicular angle; since Earth is a sphere, the temperate climates receive the sun's rays at a much steeper incidence thus spreading the radiation over a broader area. E) tropical climates receive the sun's rays at a much steeper incidence thus spreading the radiation over a broader area and causing the tropics to be warmer while the temperate climates receive the sun's rays at an almost perpendicular angle, which causes some areas to be warm and other areas to be cold.
28) Which of the following choices best describes the relationship that exists between moisture and air temperature? A) The moisture-holding capacity of air decreases when it is warm and increases when it is cool. B) The moisture-holding capacity of air remains the same (warm or cool) and is not related to its temperature. C) The moisture-holding capacity of air increases when it is warm and decreases when it is cool. D) The moisture-holding capacity of air decreases as the higher altitude winds of the polar regions descend onto the continents.
29)
Which statement best describes the relationship between elevation and latitude?
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A) Elevation and latitude are related because they are both measurements of distance. B) Elevation and latitude are related because as one increases the other increases. C) Elevation and latitude are related because they have similar effects on temperature. As the elevation increases, the temperature of the air increases, which is likewise with latitude. D) Elevation and latitude are related because they have similar effects on temperature. As the elevation increases, the temperature of the air decreases, which is likewise with latitude.
30) Biomes are broad regional areas with defined flora and fauna. Which one of the following choices correctly identifies the biomes shown plotted in the graph of precipitation versus temperature?
A) Tropical Rain forest = 1; Desert = 2; Tundra = 3; Grassland = 4 B) Tropical Rain forest = 1; Desert = 3; Tundra = 4; Grassland = 2 C) Tropical Rain forest = 3; Desert = 4; Tundra = 1; Grassland = 2 D) Tropical Rain forest = 3; Desert = 1; Tundra = 2; Grassland = 3
31) Keeping biomagnification in mind, use the following information to estimate the level of chemical X in a large-mouth bass. One alga can accumulate 1 unit of chemical X. Each copepod eats 15 algae. A minnow consumes 10 copepods, each large-mouth bass consumes 20 minnows.
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A) 15 units B) 20 units C) 30 units D) 150 units E) 300 units F) 3,000 units G) 20,000 units
32) Temperate grasslands and temperate deciduous forests are two different biomes that are located in the same latitudes. Which one of the following abiotic conditions is most likely to account for the differences in their community composition? A) temperature B) precipitation C) sunlight D) soil nutrients E) a rain shadow
33) If you plot mean annual precipitation against mean annual temperature and look at the distribution of major biomes relative to these two variables, which biome would be in the central region of the graph? A) savanna B) hot desert C) tropical rain forest D) temperate deciduous forest E) taiga
34) Which one of the following marine ecosystems would be expected to have the lowest species diversity and primary production per unit area?
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A) oligotrophic oceans B) upwelling regions of ocean C) coral reefs D) estuaries E) intertidal zone
35) A mountain range along the coast of a continent is located perpendicular to the prevailing sea breeze. Which one of the following describes an area where the rain shadow is located? A) on the leeward side of the mountain where cool, dry air is descending B) on the leeward side of the mountain where warm, moist air is descending C) on the windward side of the mountain where warm, moist air is rising D) on the windward side of the mountain where cool, dry air is rising E) on the leeward side, far inland from the mountain
36) In a temperate zone lake, what should the temperature profile be immediately after the fall overturn? A) coldest water at the top, 4° C water at the bottom B) warmest water at the top, 4° C water at the bottom C) 4° C water throughout D) 10° C water throughout E) 4° C water at the top, coldest water at the bottom
37)
Biological magnification of persistent toxins would be greatest in a A) deer. B) fox. C) black bear. D) mushroom. E) oak tree.
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38)
Which of the following adversely affects the ozone layer? A) chlorofluorocarbons B) greenhouse gases C) oil D) coal and natural gas E) plastics
39)
Which two countries are both likely to have prevailing winds blowing from west to east? A) the United States and Argentina B) the United States and Panama C) Canada and Brazil D) Panama and Brazil
40) Oxygen levels in the photic zone fluctuate over the course of a 24-hr period. If you were measuring dissolved oxygen over the course of the day, when would you expect to see the lowest levels of oxygen and why? A) Mid-morning -- because fish are most active and their respiration rates are highest. B) Early afternoon -- when the surface water warms up and sinks to the bottom. C) Mid-afternoon -- because the activity of the Calvin cycle (the dark reactions) of photosynthesis are at their peak. D) Early evening -- when animals come to feed and disturb the surface waters. E) During the night -- because the light reactions of photosynthesis are inactive.
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41) Scientists cannot predict when an El Niño will begin. But once it does, forecasters are able to predict changes to weather patterns. What would be a predicted weather effect of an El Niño?
A) Drier and warmer in the southeastern United States B) Colder than normal across the northeastern United States C) More rain in Peru and Ecuador D) More rain in Indonesia and the Phillipines
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Answer Key Test name: Chap 57_13e_Raven 1) FALSE
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Clarify Question • What is the key concept addressed by the question? o This question addresses solar radiation. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content • What do you already know about solar radiation? o A major reason for differences in solar radiation from place to place is the fact that Earth is a sphere, or nearly so. The tropics are particularly warm because the Sun’s rays arrive almost perpendicular to the surface of the Earth in regions near the equator. Closer to the poles, the angle at which the Sun’s rays strike, called the angle of incidence, spreads the solar energy out over more of the Earth’s surface, providing less energy per unit of surface area. o The Earth’s annual orbit around the Sun is also important. The axis of rotation of the Earth is not perpendicular to the plane in which the earth orbits the Sun. Because the axis is tilted by approximately 23.5°, a progression of seasons occurs on all parts of the Earth, especially at latitudes far from the equator. The northern hemisphere tilts toward the Sun during some months but away during others, giving rise to summer and winter; the farther away from the equator, the greater the difference between summer and winter. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o If the tilt of the Earth increased, it would place Boston (and the Version 1
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Northern Hemisphere) further from the sun in the Winter and closer to the sun in Summer. This would result in more extreme seasons, not less. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that the seasons are caused by the tilt of the Earth’s axis? 2) TRUE 3) [A, C, E] 4) [A, B, C, D] 5) [A, C, D, F]
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Clarify Question • What is the key concept addressed by the question? o This question addresses eutrophication. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content • What do you already know about eutrophication? o Eutrophic bodies of water are high in algal nutrients and often populated densely with algae. They are more likely to be low in dissolved oxygen, especially in summer. In a eutrophic body of water, decay microbes often place high demands on the oxygen available because when thick populations of algae die, large amounts of organic matter are made available for decomposition. Moreover, light does not penetrate eutrophic waters well because of all the organic matter in the water; photosynthetic oxygen addition is therefore limited to just a relatively thin layer of water at the top. o Human activities have often transformed oligotrophic lakes into eutrophic ones. For example, when people overfertilize their lawns or fields, nitrate and phosphate from the fertilizers wash off into local water systems. Lakes that receive these nutrients become more eutrophic. When excessive nitrates and phosphates enter rivers and lakes, the character of the bodies of water is changed for the worse; the concentration of dissolved oxygen declines, and fish species such as carp take the place of more desirable species. The problem is exacerbated when rivers empty into the ocean. The eutrophication caused by the accumulation of chemicals can lead to enormous areas of water with no oxygen, causing massive die-offs of fish and other animals. Version 1
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Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Any activity that increases nutrient input into the lake causes eutrophication. Planting trees would likely slow runoff into the lake reducing nutrient input. Plastic would not affect nutrient levels. o Dumping piles of leaves near a lake would add the nutrients that were in the leaves. o Washing clothes with soap in the lake would add phosphorus because detergents have phosphates. o Feeding the ducks in the lake would add nutrients from the food. o Fertilizing lawns near the lake would add nutrients from the fertilizer (usually N, P, and K). Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that anything that increase nutrient levels will contribute to eutrophication? 6) [A, B, D, E] 7) [A, B, D, E] 8) [B, C, D, E] 9) [B, D] 10) [A, B, D] 11) [B, D, E] Version 1
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12) [A, C, D]
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Clarify Question • What is the key concept addressed by the question? o This question addresses eutrophic vs. oligotrophic lakes. • What type of thinking is required? o This question is asking youto weigh and judge evidence, or evaluate, to choose the best of the possible answers. Gather Content • What do you already know about eutrophic vs. oligotrophic lakes? o Lakes and rivers that are low in algal nutrients (such as nitrate or phosphate) and low in the amount of algal material per unit of volume are termed oligotrophic. Such waters are often crystal clear. Oligotrophic lakes and ponds tend to be high in dissolved oxygen at all depths all year because they also have a low rate of oxygen use. o Eutrophic bodies of water are high in algal nutrients and often populated densely with algae. They are more likely to be low in dissolved oxygen, especially in summer. In a eutrophic body of water, decay microbes often place high demands on the oxygen available because when thick populations of algae die, large amounts of organic matter are made available for decomposition. o Human activities have often transformed oligotrophic lakes into eutrophic ones. For example, when people overfertilize their lawns or fields, nitrate and phosphate from the fertilizers wash off into local water systems. Lakes that receive these nutrients become more eutrophic. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o An oligotrophic lake has low nutrient levels, and consequently little Version 1
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plant growth and clear water, with high oxygen content. o So these three observations fit an oligotrophic lake: o The shoreline is mostly rock and sand with very little vegetative matter. o The lake has little planktonic growth. o The bottom of the lake is easily visible. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. o Did you recognize that clear water and little plant growth is the sign of an oligotrophic lake? 13) [B, C, E]
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Clarify Question • What is the key concept addressed by the question? o This question addresses pollution. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about pollution? o Point-source pollution comes from an identifiable location—such as easily identified factories or other facilities that add pollutants at defined locations, such as an outfall pipe. Examples include sewage-treatment plants, which discharge treated effluents at specific spots on rivers. o Diffuse pollution is harder to identify and target for remediation. An example is eutrophication caused by excessive runoff of nitrates and phosphates from lawn and agricultural field fertilization. o Solutions to diffuse pollution often depend on public education and political action. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Diffuse pollution does not have a single clear source. Instead, little bits of pollution are contributed from multiple people and areas. o Examples of diffuse pollution are: pet waste, oil runoff from roads, and bits of trash that blow out to sea. Reflect on Process
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that diffuse pollution is caused by numerous small sources of contamination? 14) D
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Clarify Question • What is the key concept addressed by the question? o This question addresses eutrophic vs. oligotrophic lakes. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about eutrophic vs. oligotrophic lakes? o Lakes and rivers that are low in algal nutrients (such as nitrate or phosphate) and low in the amount of algal material per unit of volume are termed oligotrophic. Such waters are often crystal clear. Oligotrophic lakes and ponds tend to be high in dissolved oxygen at all depths all year because they also have a low rate of oxygen use. o Eutrophic bodies of water are high in algal nutrients and often populated densely with algae. They are more likely to be low in dissolved oxygen, especially in summer. In a eutrophic body of water, decay microbes often place high demands on the oxygen available because when thick populations of algae die, large amounts of organic matter are made available for decomposition. o Human activities have often transformed oligotrophic lakes into eutrophic ones. For example, when people overfertilize their lawns or fields, nitrate and phosphate from the fertilizers wash off into local water systems. Lakes that receive these nutrients become more eutrophic. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Oligotrophic bodies of water are naturally low in nutrients. As a Version 1
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result, the growth of algae is limited. Limited algal growth keeps zooplankton levels low. The addition of the fertilizer created an opportunity for the algae populations to grow rapidly and this in turn supported more zooplankton. Once the zooplankton populations increased, more salmon could be supported in the lakes. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that some lakes have low levels of algae and thus zooplankton, due to low nutrient levels? 15) A The only ecosystem that does not depend on the sun's energy to power primary productivity is the the deep sea hydrothermal vent. 16) D
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Clarify Question • What is the key concept addressed by the question? o This question addresses precipitation. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about precipitation? o Regional differences in precipitation can occur because of rain shadows. o Deserts on land sometimes occur because mountain ranges intercept moisture-laden winds from the sea. When air flowing landward from the oceans encounters a mountain range, the air rises, and its moistureholding capacity decreases because it becomes cooler at higher altitude, causing precipitation to fall on the mountain slopes facing the sea. o As the air—stripped of much of its moisture—then descends on the other side of the mountain range, it remains dry even as it is warmed, and as it is warmed its moisture-holding capacity increases, meaning it can readily take up moisture from soils and plants. o One consequence is that the two slopes of a mountain range often differ dramatically in how moist they are, and a desert may develop on the dry side.The mountains are said to produce a rain shadow. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o In New Zealand, the Southern Alps along the West Coast intercept most of the moisture coming off the Tasman Sea, and as a result, the Version 1
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West Coast receives a lot of rain while the East Coast is extremely dry. This is like the rain shadow effect seen in the Sierra Nevada of California. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that deserts often form on the continental side of mountain ranges, due to the rain shadow effect? 17) C 18) A 19) B 20) A 21) C 22) C 23) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses thermal stratification. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about thermal stratification? o Thermal stratification is characteristic of many lakes and large ponds. In summer, water warmed by the Sun forms a layer known as the epilimnion at the surface—because warm water is less dense than cold water and tends to float on top. Colder, denser water, called the hypolimnion, lies below. Between the warm and cold layers is a transitional layer, the thermocline. Although here we are focusing on freshwater, a similar thermal structuring of the water column occurs also in many parts of the ocean. o In a lake, thermal stratification tends to cut off the oxygen supply to the bottom waters; a consequence of the stratification is that the upper waters that receive oxygen do not mix with the bottom waters. The concentration of oxygen at the bottom may then gradually decline over time as the organisms living there use oxygen faster than it is replaced. If the rate of oxygen use is high, the bottom waters may run out of oxygen and become oxygen-free be-fore summer is over. Oxygen-free conditions, if they occur, kill most animals in a lake. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o The warmest reading at the top represents the top, warm layer – the epilimnion. o The middle reading represents the middle, transitional layer – the thermocline. o The coldest reading represents the bottom, cold layer – the hypolimnion. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that lakes become stratified during the summer, with a warm epilimnion on top, a cold hypolimnion on the bottom, and a thermocline between? 24) E 25) B 26) D
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Clarify Question • What is the key concept addressed by the question? o This question addresses biomes. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about biomes? o Temperature and moisture often determine biomes.Average annual temperature and rainfall, as well as the range of seasonal variation, determine different biomes. Eight major types of biomes are recognized: o Tropical rainforests are highly productive equatorial systems. o Savannas are tropical grasslands with seasonal rainfall. o Deserts are regions with little rainfall. o Temperate grasslands have rich soils. o Temperate deciduous forests are adapted to seasonal change. o Temperate evergreen forests are coastal. o Taiga is the northern forest where winters are harsh. o Tundra is a largely frozen treeless area with a short growing season. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Would the tundra have a large number of spruce trees? No, the tundra is too cold for trees. o Would the prairie have a large number of spruce trees? No, the prairie is dominated by grass. o Would the tropical rain forest have a large number of spruce trees? Version 1
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No, spruce are poorly adapted to the warm, humid rain forest. o Would the temperate deciduous forest have a large number of spruce trees? It may have some, but not as many as colder areas. o Would the taiga have a large number of spruce trees? Yes! Spruce trees and other conifers are well-adapted to the cold. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that spruce trees are well-adapted to the cold weather of the taiga? 27) D 28) C 29) D 30) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses biomes. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about biomes? o Temperature and moisture often determine biomes. Average annual temperature and rainfall, as well as the range of seasonal variation, determine different biomes. Eight major types of biomes are recognized: o Tropical rainforests are highly productive equatorial systems. o Savannas are tropical grasslands with seasonal rainfall. o Deserts are regions with little rainfall. o Temperate grasslands have rich soils. o Temperate deciduous forests are adapted to seasonal change. o Temperate evergreen forests are coastal. o Taiga is the northern forest where winters are harsh. o Tundra is a largely frozen treeless area with a short growing season. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The graph shows temperature on the vertical axis, and precipitation (rainfall) on the horizontal axis. o So the biome graphed at the top right (1) would have high temperature and high precipitation. Which biome is hot and wet? The tropical rainforest. o The biomegraphed at the top left (2) would have high temperature and low precipitation. Which biome is hot and dry? The desert. o The biome graphed at the bottom left (3) would have low temperature and low precipitation. Which biome is cold and dry? The tundra. o The biome graphed at the bottom right (4) would have moderate temperature and moderate precipitation. Which biome is warmwith moderate rainfall? The grassland. o So the correct order is: 1. Tropical Rain forest; 2. Desert; 3. Tundra; 4. Grassland Reflect on Process
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• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that each biome has a unique combination of temperature and rainfall?
31) F
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Clarify Question • What is the key concept addressed by the question? o This question addresses biomagnification. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content • What do you already know about biomagnification? o Environmental pollutants can reach high levels in some organisms due to biomagnification. o For instance, DDT is an insecticide that was sprayed widely in the decades following World War II, often on wetlands to control mosquitoes. During the years of heavy DDT use, populations of ospreys, bald eagles, and brown pelicans—all birds that catch large fish— plummeted. Ultimately, the use of DDT was connected with the demise of these birds. o Scientists established that DDT and its metabolic products became more and more concentrated in the tissues of animals as the compounds were passed along food chains. Animals at the bottom of food chains accumulated relatively low concentrations in their fatty tissues. But the primary carnivores that preyed on them accumulated higher concentrations from eating great numbers, and the secondary carnivores accumulated higher concentrations yet. Top-level carnivores, such as the birds that eat large fish, were dramatically affected by the DDT. In these birds, scientists found that metabolic products of DDT disrupted the formation of eggshells. The birds laid eggs with such thin shells that they often cracked before the young could hatch. o Decades after DDT was banned, populations of ospreys, eagles, and Version 1
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pelicans are rebounding dramatically. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Calculating the amount of the chemical requires multiplication. o One alga can accumulate 1 unit of chemical X. Each copepod eats 15 algae. So each copepod accumulates 15 units. o A minnow consumes 10 copepods, so each minnow accumulates 10 x 15 = 150 units of the chemical. o Each large-mouth bass consumes 20 minnows. So each bass accumulates 20 x 150 = 3000 units of the chemical. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that bio magnification causes chemicals to reach high levels in top predators, because they accumulate all the chemical from the food chain below? 32) B 33) D 34) A 35) A 36) C 37) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses biomagnification. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about biomagnification? o Environmental pollutants can reach high levels in some organisms due to biomagnification. o For instance, DDT is an insecticide that was sprayed widely in the decades following World War II, often on wetlands to control mosquitoes. During the years of heavy DDT use, populations of ospreys, bald eagles, and brown pelicans—all birds that catch large fish— plummeted. Ultimately, the use of DDT was connected with the demise of these birds. o Scientists established that DDT and its metabolic products became more and more concentrated in the tissues of animals as the compounds were passed along food chains. Animals at the bottom of food chains accumulated relatively low concentrations in their fatty tissues. But the primary carnivores that preyed on them accumulated higher concentrations from eating great numbers, and the secondary carnivores accumulated higher concentrations yet. Top-level carnivores, such as the birds that eat large fish, were dramatically affected by the DDT. In these birds, scientists found that metabolic products of DDT disrupted the formation of eggshells. The birds laid eggs with such thin shells that they often cracked before the young could hatch. o Decades after DDT was banned, populations of ospreys, eagles, and Version 1
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pelicans are rebounding dramatically. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Toxic chemicals like DDT accumulate in the largest quantities in higher level carnivores like a polar bear. o A fox is also a predator, but a fox typically eats herbivores, whereas a polar bear eats other predators (seals), so it is higher up the food chain. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that top predators are most vulnerable to the effects of biomagnification? 38) A 39) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses the Coriolis effect and winds. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content • What do you already know about the Coriolis effect and winds? o If Earth did not rotate on its axis, global air movements would follow simple patterns. But the Earth rotates under the winds, so the winds move in curved paths across the surface, rather than straight paths. The curvature of the paths of the winds due to Earth’s rotation is termed the Coriolis effect. o If you were standing on the North Pole, the Earth would appear to be rotating counterclockwise on its axis, but if you were at the South Pole, the Earth would appear to be rotating clockwise. This is why the direction of the Coriolis effect is opposite in the two hemispheres. In the northern hemisphere, winds always curve to the right of their direction of motion; in the southern hemisphere, they always curve to the left. o The reason for these wind patterns is that the circumference of the Earth changes with latitude. It is zero at the poles and 38,000 km at the equator. Thus, land surface speed changes from about 0 to 1500 km per hour going from the poles to the equator. Air descending at 30° north latitude may be going roughly the same speed as the land surface below it. As it moves toward the equator, however, it is moving more slowly than the surface below it, so it is deflected to its right in the northern hemisphere and to its left in the southern hemisphere. In other words, in both the northern and southern hemispheres, the winds blow westward Version 1
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as well as toward the equator. The result is that winds on both sides of the equator—called the Trade Winds—blow out of the east and toward the west. o Conversely, air masses moving north from 30° are moving more rapidly than underlying land surfaces and thus are deflected again to their right, which in this case is eastward. Similarly, in the southern hemisphere, air masses between 30° and 60° are deflected eastward, to the left. In both hemispheres, therefore, winds between 30° and 60° blow out of the west and toward the east; these winds are called Westerlies. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o In North America, the Westerly winds blow from west to east. On both sides of the equator, the Trade Winds blow from east to west. Further south in the southern hemisphere, though, countries like Argentina have winds from west to east. So the pair of countries with west-to-east winds is the United States and Argentina. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that in the United States, the prevailing winds are the Westerlies, that blow from west to east? 40) E
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Clarify Question • What is the key concept addressed by the question? o This question addresses oxygen levels. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content • What do you already know about oxygen levels? o The light reactions of photosynthesis create oxygen, but only during the daytime when light is available, and only in the photic zone. o Water absorbs light passing through it, and the intensity of sunlight available for photosynthesis decreases sharply with increasing depth. In deep lakes, only water relatively near the surface receives enough light for phytoplankton to exhibit a positive net primary productivity. Those waters are described as the photic zone. o The supply of dissolved oxygen to the deep waters of a lake can be a problem because oxygen enters aquatic systems near their surface, where gas exchange occurs with the air and photosynthesis occurs in aquatic organisms. In the still waters of a lake, mixing between the surface and deeper layers may not occur except occasionally as a result of thermal stratification; consequently, oxygen only rarely enters the deep waters from the surface waters. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Oxygen levels would be lowest at night when the light reactions of photosynthesis are quiet. The light reactions produce oxygen not the Version 1
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Calvin cycle. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that photosynthesis produces oxygen only while the sun is up? 41) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses El Niño. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about El Niño? o Every two to seven years on an irregular and relatively unpredictable basis, the water along the Peru-Ecuador coastline becomes warm, and the primary productivity becomes unusually low. This is called El Niño. o Because of the low primary productivity, the ordinarily prolific fish populations weaken, and populations of seabirds and sea mammals that depend on the fish are stressed and plummet. o The cause of El Niño is a weakening of the east-to-west Trade Winds in the region. The Trade Winds ordinarily blow warm surface water to the west, away from the Peru–Ecuador coast. This thins the warm surface layer of water along the coast, so that deep water—cold but highly rich in nutrients—is drawn to the surface, leading to high primary production. Weakening of the Trade Winds allows the warm surface layer to become thicker. Upwelling continues, but under such circumstances it merely recirculates the thick warm surface layer, which is nutrient-depleted. o The weakening of the Trade Winds is actually part of a change in wind circulation patterns that recurs irregularly. One reason the Trade Winds blow east-to-west in ordinary times is that the surface waters in the western equatorial Pacific are warmer than those in the eastern equatorial Pacific; air rises from the warm western areas, creating low pressure at the surface there, and air blows out of the east into the low pressure. During an El Niño, the warmer the eastern ocean gets, the more similar it becomes to the western ocean, reducing the difference in pressure across the ocean. Thus, once the Trade Winds weaken a bit, the pressure difference that makes them blow is lessened, weakening the Trade Winds further. o One specific result of an El Niño is to shift the weather systems of the western Pacific Ocean 6000 km eastward. The tropical rainstorms that usually drench Indonesia and the Philippines occur when warm seawater abutting these islands causes the air above it to rise, cool, and condense its moisture into clouds. When the warm water moves east, so do the clouds, leaving the previously rainy areas in drought. Conversely, the western edge of Peru and Ecuador, which usually receives little precipitation, gets a soaking. In addition, the northern United States and Canada are warmer, and the southeastern United States is cooler and rainier. Choose Answer • Given what you now know, what information and/or problem solving approach is most Version 1
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likely to produce the correct answer? o During an El Niño, topical rainstorms that usually drench Indonesia and the Philippines move eastward instead and bring rain to Peru and Ecuador. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that El Niño causes a reversal of weather patterns, bringing extra rain to the Americas?
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Chapter 58 13e CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 1) While reading an online science magazine, you come across an article on declining turtle populations across the globe. Based on the graph, what would you guess are the two biggest factors in the decline? Choose two.
A) Harvesting of turtles for food, pets, or medicine B) Competition with invasive species C) Destruction of wetlands and breeding beaches D) Developmental problems due to rising temperatures E) Disease from introduced parasites
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2) The following graph shows the relationship between extinction and habitat area. Which statements help explain the trend shown on the graph? Check all that apply.
A) Larger patches are more likely to be encountered by new immigrants. B) Larger patches are likely to have a more uniform habitat. C) Larger patch size reduces genetic drift. D) Larger patches are more geographically isolated than smaller patches. E) Species richness is higher on larger patches.
3)
Human caused introductions can occur by which of the following? Check all that apply. A) plants and animalsaccidentally escaping from ships B) automobile ortruck tires C) being in the soilor on a plant sold at a nursery D) seeds or organismsattaching to clothing or shoes E) international cargo ships releasing ballast water in the ocean before arriving at port
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4) In western Sweden, coastal marine ecosystems have been exposed to discharge of nutrients over several decades. As a result, algal blooms are more common.Algal mats on the sea bottom limit sunlight and alter the amount of dissolved oxygen in the water. Additionally, some algae produce toxic compounds that can enter shellfish. Furthermore, the decomposing algae produces a strong odor. Which statements below correctly match the outcomes to their effects on value of the ecosystem? Check all that apply. A) Aesthetic value is lost because the algae makes the beach ugly and smells terrible. B) Indirect economic value is lost because fisherman cannot catch their usual fish. C) Direct economic value is lost because the toxic shellfish cannot be eaten. D) Aesthetic value is gained because the algae could be used for biomass. E) Direct economic value is lost because the properties near the beach aren’t as desirable.
5)
What becomes more likely to occur in a small population? Check all that apply. A) the Allee effect B) increased genetic drift C) increased genetic diversity D) extinction vortex E) increased edge effect
6)
As a population declines in size, what would you predict? Check all that apply. A) Loss of genetic variation B) More individuals with heterozygote advantage C) Deleterious alleles can become fixed due to chance D) Homozygosity within individuals in the population will decline E) The few remaining individuals will be tough, healthy and fertile F) If the environment changes, the population will adapt quickly
7) Without elephants, African grasslands convert to forests or to shrublands. Which of the following phrases are true statements about the elephant? Check all that apply.
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A) The elephant is a keystone species. B) If elephants went extinct, other species in the area would be unaffected. C) Elephants graze on young shrubs and trees. D) Elephants are the most abundant species on the grassland. E) Grazing antelope depend on the presence of the elephant.
8)
Captive breeding (Check all that apply)
A) is a viable strategy whenever very few individuals of a species remain in the wild. B) has had limited success restoring California condor populations in the western United States because of reduced genetic heterogeneity. C) sometimes deals with low genetic variability and inbreeding. D) is sometimes a part of efforts to restore ecosystems to a balanced, functional state. E) successfullyincreased peregrine falcon populations.
9) The American redstart ( Setophagaruticilla) is in serious decline. Scientists have been able to correlate health and breeding success to levels of 13C in their blood (a chemical signature indicating the source of their diet). Birds with lower levels of 13C in their blood return to their spring breeding ground sooner, weigh more and produce more offspring. Based on this, what would you expect to find in the wintering grounds of the American redstart? Check all that apply. A) Limited availability of habitat in areas where plants have low13C B) Higher insect biomass in areas where plants have low13C C) A lack of territorial behavior being displayed by American redstarts D) Differences in food quality correlating with levels of 13C in the habitat E) Similar flora and fauna in all redstart habitats, unrelated to levels of 13C
10) Which of the following is a recognized way that the processes of natural selection and speciation may mitigate the concerns of conservation biologists?
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A) Hybridization between an introduced and a native species can promote speciation, especially in plants. B) Hybridization between two introduced species can promote speciation, especially in plants. C) Species that go extinct provide additional resources for populations that remain intact. D) The fragmentation of habitats promotes geographic isolation of populations, an important aspect of speciation.
11) Which of the following is a reason that conservation biologists have begun to use phylogenetic trees to assist in determining where to direct the limited resources that support conservation efforts? A) Species with numerous, closely related groups are more likely to survive extinction due to hybridization with those closely related groups. B) Distinct species are valuable because they represent a part of life that, if lost, cannot be recovered. C) Phylogenetic trees can demonstrate species with few close relatives that are more likely to possess unique features and adaptations not shared by other species. D) Conservation biologists do not use phylogenetic trees to make decisions about limited resource use, the diagrams are used strictly in the study of evolution.
12) Modern restoration biologists recognize that it may not be prudent to restore the same species to an ecosystem that has been disturbed. Which of the following statements and or explanations supports this? A) Due to global warming certain species may no longer flourish in the ecosystem. B) Often we do not have a full list of species that made up the original ecosystem. C) Restoring an ecosystem requires a replica of the original state, this version of restoration is called "pristine." D) Restoring an ecosystem should involve rebuilding the systems that allowed the habitat to successfully operate.
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MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 13) Scientists estimate that about _____ of the world's eukaryotic organisms have been discovered and given scientific names. A) 1% B) 5% C) 15% D) 40% E) 90%
14) An organism whose decline or removal from a habitat causes many other species numbers to change dramatically is called __________ species. A) a keystone B) a synergistic C) a nominal D) an introduced
15)
The process of examining the genomes of animals and plants for useful genes is A) gene prospecting. B) genetic engineering. C) phenotypic labeling. D) cloning.
16) A friend asks you for a definition of endemic because she is writing a history paper and this word keeps occurring in the literature in reference to bison on the Great Plains of the United States. Your response is that the word endemic means
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A) a species that has gone extinct since humans have evolved on Earth. B) a species that exists in many habitats on Earth. C) a species that has coevolved with humans on Earth. D) a species that lives in only one area of Earth.
17)
Regarding megafaunal extinctions, it is assumed that the driving factor was A) climate change. B) the Ice Age. C) Homo sapiens. D) a meteorite. E) rising sea levels.
18)
Edge effects are the result of which of the following?
A) Populations of flora and fauna have emigrated from the core of their population center to the edge of their habitat. B) Metapopulations of some of the larger fauna have become more dominant on the landscape and as a result have increased the edge of their habitat. C) Habitat fragmentation or habitat shrinkage has occurred, and thus the edge of the habitat has increased in relative proportion. D) Habitat fragmentation or habitat shrinkage has occurred, and thus the edge of the habitat has decreased in relative proportion. E) Populations of particular species have decreased and are on the edge of extinction.
19) A scientist studied peregrine falcons to determine why the numbers of birds was declining. She determined that
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A) global warming (too much carbon dioxide) had increased the death rates in the newly hatched chicks. B) the genetic diversity of the falcons was too low to sustain their population level. C) the falcons had lost much of their habitat due to human developments. D) the falcon's habitat had been fragmented and the subsequent edge effect affected their ability to hunt for prey items. E) the levels of DDT in the environment were having a detrimental effect on eggs (causing the eggshells to be too thin) that were being laid by the female falcons.
20) Sea otters have been used as an example of the "Keystone Species" concept. This means that sea otters A) are the base of the food chain in their ecosystem. B) are the dominant species in their ecosystem. C) exert a strong influence on the structure and functioning of their ecosystem. D) have been recently introduced and are recruiting other new species to the ecosystem.
21) Island species are particularly vulnerable to extinction for all of the following reasons except A) humans have altered habitats. B) island species have lost the ability to escape predators. C) humans have introduced competitors. D) humans have introduced diseases. E) fewer endemic species are found on islands.
22) A small island has stable populations of plants and animals, including one species of hawk but no other large predators. A ship docks at the island, and the ship's cat escapes. If the cat was pregnant, what do you think the sailors are likely to find if they return ten years later?
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A) The island will have similar flora and fauna, with the addition of a cat population. B) The increase in nitrogenous waste from the cats will increase plant productivity. C) The bird and lizard species on the island will have many new adaptations. D) Some species of ground-nesting birds may have gone extinct. E) Species that were formerly preyed upon by hawks will benefit.
23) A small island has stable populations of plants and animals, including one species of hawk but no other large predators. A ship docks at the island, and the sailors hunt and kill most of the hawks. What would you expect as an immediate consequence? A) an increase in the plants B) an increase in the insects C) an increase in the rodents D) a decrease in the fish E) a decrease in the plants
24)
A major problem with hotspots is humans moving in and causing A) habitat destruction. B) increased genetic diversity. C) increased immigration among species. D) decreased introductions. E) decreased biomagnification.
25) The West African black rhino, one of four subspecies of rhinoceros, was declared extinct in 2006. Their horns were believed by many to hold medicinal value. What is the most likely reason for the extinction of the West African black rhino?
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A) habitat loss B) overexploitation C) introduced species D) pollution E) climate change
26) Which of the following whale species are recovering their population numbers as a result of whale harvesting regulations? I-right whales II-Pacific gray whales III-sperm whales IV-fin whales V-humpback whales A) I and II B) I, II, and III C) II and V D) I, II, III, and IV E) I, II, and V
27) The various endemic cichlid species of Lake Victoria have suffered losses in their population numbers and species due to the introduction of A) the Nile crocodile. B) the Nile perch. C) a new algae species. D) a new ectoparasite that lives on the gills. E) a fish hawk.
28) Why might the different species of whales fail to recover even though hunting has been banned?
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A) loss of genetic diversity B) loss of habitat C) introduction of invasive species D) increasing predation E) increased disease spread due to edge effects
29)
When New York City was given a choice to make regarding its drinking water A) they opted for more bottled water. B) they chose ecosystem maintenance over development. C) they had to construct expensive filtration plants to protect against disease. D) they chose ecosystem conversion to higher density housing for efficiency. E) they dug new and deeper wells rather than pay for desalinization.
30)
In the last 20 years one concern of scientists who study amphibians is that A) genetic diversity is being increased too rapidly for proper maintenance. B) the edge effects are causing declines in species numbers. C) DDT is affecting reproduction by thinning the egg membranes. D) populations are diversifying rapidly and speciation is occurring. E) many species are declining or have gone extinct in recent years.
31)
Ecologists are concerned about amphibian populations because A) their loss would be an aesthetic loss to the planet. B) of the possibility of numerous medicinal uses. C) they are keystone species in many areas—their loss will cause other populations to
crash. D) amphibians are very sensitive to environmental change—they may be indicating serious problems. E) they are increasing to the point of competing with indigenous species.
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32)
Natural colonization can happen in all of the following ways except A) a flock of birds gets blown off course. B) a bird eats a fruit on the mainland and defecates the seed on an island. C) people plant new species on an island. D) lowered sea levels connect two areas previously isolated. E) birds pick up seeds on their feet while wading in mud and drop them elsewhere.
33)
The extinction vortex
A) is what happens as a population decreases and becomes more vulnerable to extinction from a variety of causes. B) begins when one species in an ecosystem goes extinct and other species follow. C) is what happens when competing species fight over a single niche, often driving both species to extinction. D) is a spiral of events that occur once a species has become overcrowded through excess reproduction. E) is a spiral of events that includes introduction of competing species, overexploitation, and disease, in that order.
34) A conservation group is deciding what land to preserve. Why might they want to consider an area of land where the ecosystem is partially damaged by a logging contract that cannot be overturned? A) Conservation groups often focus of fixing damaged land and ecosystems. B) When conservation groups choose land to preserve, they just consider what is best for the one target species that is endangered. C) By making logging difficult, they strengthen environmentalism. D) Human activity often leads to the evolution of unique species that take advantage of the disrupted environment.
35) Which of the statements given below supports the idea that frog populations can demonstrate the phenomenon of evolutionary rescue?
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A) Frog populations have started to rebound as a result of the evolution of resistance to specific fungal diseases. B) Frog populations have started to decline as a result of the evolution of resistance to specific fungal diseases. C) Frog populations have moved to more temperate environments to find more suitable habitats to support their lifestyle. D) Frog populations have moved to more tropical environments to find more suitable habitats to support their lifestyle.
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Answer Key Test name: Chap 58_13e_Raven 1) [A, C]
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Clarify Question • What is the key concept addressed by the question? o This question addresses causes of extinction. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about causes of extinction? o A variety of causes are responsible for extinctions. Habitat loss is the major problem for most animals today. Introduced species and over exploitation are two more major causes. o Many other factors contribute to species extinctions as well, including disruption of ecosystem interactions, pollution, loss of genetic variation, and catastrophic disturbances, either natural or human-caused. o More than one of these factors may affect a species. In fact, a chain reaction is possible in which the action of one factor predisposes a species to be more severely affected by another factor. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o According to the graph, the biggest factor threatening turtle populations is habitat loss, and the second biggest factor is over exploitation. Introduced species and other factors affect fewer of the species. o Is one of the two biggest factors competition with invasive species, or disease from introduced parasites? No, because both of these can be attributed to introduced species. o Is one of the two biggest factors developmental problems due to rising temperatures? No. This is a problem for some turtle species (due to temperature-dependent sex determination), but according to the graph this is not one of the two biggest factors. o Is one of the two biggest factors harvesting of turtles for food, pets, or medicine? Yes, this is over exploitation, a big factor for turtles according to the graph. o Is one of the two biggest factors destruction of wetlands? Yes, this is habitat loss, another big factor for turtles according to the graph. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the Version 1
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process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that habitat loss and over exploitation are two major causes of extinction?
2) [A, C, E]
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Clarify Question • What is the key concept addressed by the question? o This question addresses habitat area and extinction. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content • What do you already know about habitat area and extinction? o Too often, part of the habitat for a particular species may simply be destroyed. This destruction is a common occurrence in the “clear-cut” harvesting of timber, in the burning of tropical forest to produce grazing land, and in urban and industrial development. Deforestation has been, and continues to be, by far the most pervasive form of habitat disruption -- many tropical forests are being cut or burned at a rate of 1% or more per year. o Biologists have a well-established observation that larger areas support more species. Although this relationship varies according to geographic area, type of organism, and type of area, in general a 10-fold increase in area leads to approximately a doubling in the number of species. This relationship suggests, conversely, that if the area of a habitat is reduced by 90%, so that only 10% remains, then half of all species will be lost. Evidence for this hypothesis comes from a study in Finland of extinction rates of birds on habitat islands (that is, islands of a particular type of habitat surrounded by unsuitable habitat) where the population extinction rate was found to be inversely proportional to island size. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The theory of island biogeography predicts that larger islands have greater habitat heterogeneity (more diverse habitats) and therefore have greater species richness than smaller islands. Larger islands have larger habitats and therefore can support larger populations. The larger the population the less likely the populations would experience severe declines due to chance events. A larger population is less subject to genetic drift. Finally, larger islands may also be easier to find and colonize. This is called the target area effect. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more Version 1
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desirable result? o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that larger habitats can support many more species, and help protect species from extinction? o What implication does this have for conservation efforts?
3) [A, B, C, D] 4) [A, C]
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Clarify Question • What is the key concept addressed by the question? o This question addresses the economic value of ecosystems. • What type of thinking is required? o This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. Gather Content • What do you already know about the economic value of ecosystems? o The direct economic value of biodiversity includes resources for our survival, such as sources of food, medicine, clothing, biomass (for energy and other purposes), and shelter. By conserving biodiversity, we maintain the option of finding useful benefits in the future. o Indirect economic value is derived from ecosystem services, such as maintaining the quality of natural water, buffering ecosystems against storms and drought, preserving soils and preventing loss of minerals and nutrients, moderating local and regional climate, absorbing pollution, and promoting the breakdown of organic wastes and the cycling of minerals. Economists have shown that intact ecosystems are often more valuable than the products derived by destroying them. o The aesthetic value of biodiversity is from the pleasure that humans receive when they are able to experience natural beauty. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Aesthetic value is from the beauty of nature. So in this case, aesthetic value is lost because the algae makes the beach ugly and smells terrible. Version 1
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o Direct economic value is due to resources that the ecosystem provides us, like food or shelter. So direct economic value is lost because the toxic shellfish cannot be eaten. o Indirect economic value is from ecosystem services, not direct resources like fish. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. o Did you recognize that an ecosystem can provide value in different ways? 5) [A, B, D]
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Clarify Question • What is the key concept addressed by the question? o This question addresses population size. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content • What do you already know about population size? o As populations decrease in size, demographic and genetic factors combine to cause what has been termed an “extinction vortex.” o As it gets smaller, it becomes more vulnerable to demographic catastrophes. Genetic variation is lost, causing re productive rates to decline and population numbers to decline even further. Eventually, the population disappears entirely, but attributing its demise to one particular factor would be misleading. o When populations become extremely small, bad luck can spell the end. For example, the dusky seaside sparrow dwindled to a population of five individuals, all of which happened to be males. In a large population, the probability that all individuals will be of one sex is infinitesimal. But in small populations, just by the luck of the draw, it is possible that 5 or 10 or even 20 consecutive births will all be individuals of one sex, and that can be enough to send a species to extinction. In addition, when populations are small, individuals may have trouble finding each other (the Allee effect), thus leading the population into a downward spiral toward extinction. Choose Answer • Given what you now know, what information and/or problem Version 1
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solving approach is most likely to produce the correct answer? o A small population will suffer from: the Allee effect (individuals have trouble finding mates), increased genetic drift, decreased genetic diversity, and possibly an extinction vortex as these different factors synergize. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that small populations suffer in several ways, as lower genetic diversity increases genetic drift, and they have trouble finding mates as well? 6) [A, C]
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Clarify Question • What is the key concept addressed by the question? o This question addresses population size and genetic diversity. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content • What do you already know about population size and genetic diversity? o Small populations face a dilemma. They are prone to the loss of genetic variation as a result of genetic drift. Many small populations have little or no genetic variability. o Genetichomogeneity can be catastrophic. Variation is beneficial because of heterozygote advantage and because genetically variable individuals tend not to have two copies of deleterious recessive alleles. Populations lacking variation are often composed of sickly, unfit, or sterile individuals. o Studies of zoo and natural populations reveal that more genetically variable individuals have greater fitness. Furthermore, in the longer term, populations with low variation have less ability to adapt to changing environments. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o As a population shrinks, will more individuals have heterozygote advantage? No, there will be fewer heterozygotes due to genetic drift. o Will homozygo sity within individuals in the population decline? No, Version 1
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it will increase. o Will the few remaining individuals be tough, healthy and fertile? No, they will likely be sickly and sterile. o Will the population adapt quickly if the environment changes? No, there will not be variation to be selected upon. o Will there be a loss of genetic variation? Yes. o Will deleterious alleles become fixed due to chance? Yes, due to more genetic drift. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that as a population declines in number genetic variability goes down, leading to sickly individuals that may carry two copies of deleterious alleles, and less variation for adapting to new conditions? 7) [A, C, E]
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Clarify Question • What is the key concept addressed by the question? o This question addresses the concept of keystone species. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about the concept of keystone species? o A keystone species exerts a greater influence on the structure and functioning of an ecosystem than might be expected solely on the basis of its abundance. The removal of a keystone species can have disastrous consequences. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The elephant is more important to this ecosystem than we might predict from its numbers. Thus we can say that the elephant is a keystone species. o If elephants went extinct, other species in the area would be greatly affected. o Elephants maintain grassland because they feed on the competitors of grass -- they graze on young shrubs and trees. o Elephants are not most abundant species on the grassland. But they are surprisingly important. o Grazing antelope depend on the presence of the elephant, because they eat the grass that the elephant maintains.
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that elephants are a keystone species – a species that is surprisingly important, even if not common? 8) [A, C, D, E] 9) [A, B, D]
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Clarify Question • What is the key concept addressed by the question? o This question addresses habitat loss and songbirds. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content • What do you already know about habitat loss and songbirds? o Over the last 50 years, forest songbirds have declined severely, especially among long-distance migrants. These birds nest in northern forests in the summer, but spend their winters in South or Central America or the Caribbean Islands. o The culprit responsible for this widespread decline appears to be habitat fragmentation and loss, especially the availability of critical winter habitat in Central and South America. o Studies of the American redstart clearly indicate that birds with better winter habitat have a superior chance of successfully migrating back to their breeding grounds in the spring. In one study, scientists were able to determine the quality of the habitat that particular birds used during the winter by examining levels of the stable carbon isotope 13C in their blood. Plants growing in the best habitats in Jamaica and Honduras (mangroves and wetland forests) have low levels of 13C, and so do the redstarts that feed on the insects that live in them. Of these wet-forest birds, 65% maintained or gained weight over the winter. o By contrast, plants growing in substandard dry scrub have high levels of 13C, and so do the redstarts that feed in those habitats. Scrub-dwelling birds lost up to 11% of their body mass over the winter. Now here’s the key: Birds that winter in the substandard scrub leave later in the spring Version 1
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on the long flight to northern breeding grounds, arrive later at their summer homes, and have fewer young. o Thus, loss of mangrove habitat in the neotropics is having a quantifiable negative influence. As the best habitat disappears, over wintering birds fare poorly, and this leads to decreased reproduction and population declines. o Unfortunately, the Caribbean lost about 10% of its mangroves in the 1980s, and continues to lose about 1% per year. This loss of key habitat appears to be a driving force in the looming extinction of some songbirds. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o American redstarts primarily overwinter in Central and South America. The preferred wintering grounds are mangroves and wetland forests, which have lower levels of 13C. Plants in these habitats retain their leaves throughout the winter and is both a food source and a refuge for insects. There is strong competition among birds to secure territories in these habitats. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that the different levels of 13C in the birds is a marker of food quality in their winter breeding grounds, and thus an Version 1
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indication of loss of high quality habitat? 10) [A, B, D] 11) [B, C] 12) [A, B, D] 13) C 14) A 15) A 16) D 17) C 18) C 19) E 20) C 21) E 22) D
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Clarify Question • What is the key concept addressed by the question? o This question addresses causes of extinction. • What type of thinking is required? o This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. Gather Content • What do you already know about causes of extinction? o A variety of causes are responsible for extinctions. Habitat loss is the major problem for most animals today. Introduced species and over exploitation are two more major causes. o Many other factors contribute to species extinctions as well, including disruption of ecosystem interactions, pollution, loss of genetic variation, and catastrophic disturbances, either natural or human-caused. o More than one of these factors may affect a species. In fact, a chain reaction is possible in which the action of one factor predisposes a species to be more severely affected by another factor. o The majority of historic extinctions—though by no means all of them—have occurred on islands. For example, of the 85 species of mammals that have gone extinct in the last 400 years, 60% lived on islands. The particular vulnerability of island species probably results from a number of factors: Such species have often evolved in the absence of predators, and so have lost their ability to escape both humans and introduced predators such as rats and cats. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Version 1
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o Is it likely that the island will have similar flora and fauna, with the addition of a cat population? No, on a small island a population of cats is likely to affect the ecosystem. o Is it likely that the increase in nitrogenous waste from the cats will increase plant productivity? No, because any nitrogen the cats get must come from the island – they cannot import new nutrients. o Is it likely that the bird and lizard species on the island will have many new adaptations? This is unlikely in such a short span of time. o Is it likely that species that were formerly preyed upon by hawks will benefit? Not likely. Cats aren’t very good at catching raptors like a hawk. If the hawks eat the cats, then the hawk population will only grow, and is likely to continue eating other prey as well. o Is it likely that some species of ground-nesting birds may have gone extinct? Yes. Unfortunately, this scenario has played out on islands in the past. Ground-dwelling island birds are often poorly adapted to predators like a cat. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. o Did you recognize that introduced cats have contributed to the extinction of island bird species, since they could not adapt quickly enough to a new predator? 23) C
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Clarify Question • What is the key concept addressed by the question? o This question addresses causes of extinction. • What type of thinking is required? o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer. Gather Content • What do you already know about causes of extinction? o A variety of causes are responsible for extinctions. Habitat loss is the major problem for most animals today. Introduced species and over exploitation are two more major causes. o Many other factors contribute to species extinctions as well, including disruption of ecosystem interactions, pollution, loss of genetic variation, and catastrophic disturbances, either natural or human-caused. o More than one of these factors may affect a species. In fact, a chain reaction is possible in which the action of one factor predisposes a species to be more severely affected by another factor. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Most hawk species feed on rodents. A reduction in the hawk population will lead to at least a temporary increase in the rodent population. Reflect on Process • Did your problem-solving process lead you to the correct answer? Version 1
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If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer. o Did you recognize that population changes in a predator can affect other species in the food chain? 24) A 25) B
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Clarify Question • What is the key concept addressed by the question? o This question addresses causes of extinction. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about causes of extinction? o A variety of causes are responsible for extinctions. Habitat loss is the major problem for most animals today. Introduced species and overexploitation are two more major causes. o Many other factors contribute to species extinctions as well, including disruption of ecosystem interactions, pollution, loss of genetic variation, and catastrophic disturbances, either natural or human-caused. o More than one of these factors may affect a species. In fact, a chain reaction is possible in which the action of one factor predisposes a species to be more severely affected by another factor. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o The West African black rhino was a victim of widespread poaching (overexploitation) due to a common belief that their horns could cure cancer and male infertility problems. Reflect on Process • Did your problem-solving process lead you to the correct answer? Version 1
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If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that even an incorrect belief about the medicinal value of an animal part can lead to the extinction of a species by overexploitation? 26) C 27) B 28) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses genetic diversity. • What type of thinking is required? o This question is asking you to take what you already know and apply it to this unfamiliar situation. Gather Content • What do you already know about genetic diversity? o Several factors may synergize to threaten a species. In fact, a chain reaction is possible in which the action of one factor predisposes a species to be more severely affected by another factor. o For example, habitat destruction may lead to decreased birth rates and increased mortality rates. As a result, populations become smaller and more fragmented, making them more vulnerable to disasters such as floods or forest fires, which may eliminate populations. Also, as the habitat becomes more fragmented, populations become isolated, so that genetic interchange ceases and areas devastated by disasters are not recolonized. Finally, as populations become very small, inbreeding increases, and genetic variation is lost through genetic drift, further decreasing population fitness. Which factor acts as the final coup de grace may be irrelevant; many factors, and the interactions between them, may have contributed to a species’ eventual extinction. Choose Answer • Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o After a population once falls to a low size, it may suffer lasting problems due to a lack of genetic diversity. Version 1
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Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to take what you already know and apply it to this unfamiliar situation. o Did you recognize that even if a threatened population recovers, it can suffer lasting effects from going through a genetic bottleneck? 29) B 30) E 31) D 32) C 33) A 34) A
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Clarify Question • What is the key concept addressed by the question? o This question addresses conservation. • What type of thinking is required? o This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. Gather Content • What do you already know about conservation? o Historically, conservationists strived to solve the problems of habitat fragmentation by focusing solely on preserving as much land as possible in a pristine state. Increasingly, however, it has become apparent that the amount of land that can be preserved in such a state is limited; moreover, many areas that are not completely protected nonetheless provide suitable habitat for many species. o As a result, conservation plans are becoming multidimensional, including not only pristine areas, but also surrounding areas in which some level of human disturbance is permitted. Isolated patches of habitat lose species far more rapidly than large preserves do. By including these other, less pristine areas, the total amount of area available for many species is increased. o The key to managing such large tracts of land successfully over a long time is to operate them in a way compatible with local land use. For example, although no economic activity is allowed in the core pristine area, the remainder of the land may be used for nondestructive harvesting of resources. Even areas in which hunting of some species is allowed provide protection for many other species. Choose Answer Version 1
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• Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? o Even disturbed land can help support some species, especially if it can act as a corridor to connect other pristine areas. Reflect on Process • Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result? o The question required you to weigh and judge evidence, or evaluate, to choose the best of the possible answers. o Did you recognize that sometimes the size of a habitat is more important than keeping it totally pristine? 35) A
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